for Journals by Title or ISSN
for Articles by Keywords
help
  Subjects -> ENGINEERING (Total: 2268 journals)
    - CHEMICAL ENGINEERING (190 journals)
    - CIVIL ENGINEERING (183 journals)
    - ELECTRICAL ENGINEERING (103 journals)
    - ENGINEERING (1201 journals)
    - ENGINEERING MECHANICS AND MATERIALS (380 journals)
    - HYDRAULIC ENGINEERING (55 journals)
    - INDUSTRIAL ENGINEERING (67 journals)
    - MECHANICAL ENGINEERING (89 journals)

CIVIL ENGINEERING (183 journals)                     

Showing 1 - 183 of 183 Journals sorted alphabetically
ACI Structural Journal     Full-text available via subscription   (Followers: 17)
Acta Polytechnica : Journal of Advanced Engineering     Open Access   (Followers: 2)
Acta Structilia : Journal for the Physical and Development Sciences     Open Access   (Followers: 2)
Advances in Civil Engineering     Open Access   (Followers: 35)
Advances in Structural Engineering     Full-text available via subscription   (Followers: 28)
Ambiente Construído     Open Access   (Followers: 1)
American Journal of Civil Engineering and Architecture     Open Access   (Followers: 30)
Architectural Engineering     Open Access   (Followers: 4)
Archives of Civil and Mechanical Engineering     Full-text available via subscription   (Followers: 1)
Archives of Civil Engineering     Open Access   (Followers: 10)
Archives of Hydro-Engineering and Environmental Mechanics     Open Access   (Followers: 2)
ATBU Journal of Environmental Technology     Open Access   (Followers: 4)
Australian Journal of Structural Engineering     Full-text available via subscription   (Followers: 6)
Baltic Journal of Road and Bridge Engineering     Full-text available via subscription   (Followers: 1)
BER : Building and Construction : Full Survey     Full-text available via subscription   (Followers: 10)
BER : Building Contractors' Survey     Full-text available via subscription   (Followers: 4)
BER : Building Sub-Contractors' Survey     Full-text available via subscription   (Followers: 3)
BER : Survey of Business Conditions in Building and Construction : An Executive Summary     Full-text available via subscription   (Followers: 4)
Bioinspired Materials     Open Access   (Followers: 5)
Bridge Structures : Assessment, Design and Construction     Hybrid Journal   (Followers: 15)
Building and Environment     Hybrid Journal   (Followers: 15)
Building Women     Full-text available via subscription  
Built Environment Project and Asset Management     Hybrid Journal   (Followers: 15)
Bulletin of Pridniprovsk State Academy of Civil Engineering and Architecture     Open Access   (Followers: 6)
Canadian Journal of Civil Engineering     Hybrid Journal   (Followers: 12)
Case Studies in Engineering Failure Analysis     Open Access   (Followers: 8)
Case Studies in Nondestructive Testing and Evaluation     Open Access   (Followers: 11)
Case Studies in Structural Engineering     Open Access   (Followers: 9)
Cement and Concrete Composites     Hybrid Journal   (Followers: 17)
Challenge Journal of Concrete Research Letters     Open Access   (Followers: 2)
Challenge Journal of Structural Mechanics     Open Access   (Followers: 5)
Change Over Time     Full-text available via subscription   (Followers: 2)
Civil and Environmental Engineering     Open Access   (Followers: 7)
Civil And Environmental Engineering Reports     Open Access   (Followers: 5)
Civil and Environmental Research     Open Access   (Followers: 19)
Civil Engineering = Siviele Ingenieurswese     Full-text available via subscription   (Followers: 4)
Civil Engineering and Architecture     Open Access   (Followers: 17)
Civil Engineering and Environmental Systems     Hybrid Journal   (Followers: 3)
Civil Engineering and Technology     Open Access   (Followers: 10)
Civil Engineering Dimension     Open Access   (Followers: 8)
Cohesion and Structure     Full-text available via subscription   (Followers: 2)
Composite Structures     Hybrid Journal   (Followers: 265)
Computer-aided Civil and Infrastructure Engineering     Hybrid Journal   (Followers: 11)
Computers & Structures     Hybrid Journal   (Followers: 36)
Concrete Research Letters     Open Access   (Followers: 6)
Construction Economics and Building     Open Access   (Followers: 2)
Construction Engineering     Open Access   (Followers: 9)
Construction Management and Economics     Hybrid Journal   (Followers: 22)
Construction Science     Open Access   (Followers: 4)
Constructive Approximation     Hybrid Journal  
Curved and Layered Structures     Open Access   (Followers: 2)
DFI Journal : The Journal of the Deep Foundations Institute     Hybrid Journal   (Followers: 1)
Earthquake Engineering and Structural Dynamics     Hybrid Journal   (Followers: 16)
Enfoque UTE     Open Access   (Followers: 4)
Engineering Project Organization Journal     Hybrid Journal   (Followers: 7)
Engineering Structures     Hybrid Journal   (Followers: 13)
Engineering Structures and Technologies     Hybrid Journal   (Followers: 2)
Engineering, Construction and Architectural Management     Hybrid Journal   (Followers: 14)
Environmental Geotechnics     Hybrid Journal   (Followers: 5)
European Journal of Environmental and Civil Engineering     Hybrid Journal   (Followers: 9)
Fatigue & Fracture of Engineering Materials and Structures     Hybrid Journal   (Followers: 16)
Frattura ed Integrità Strutturale : Fracture and Structural Integrity     Open Access  
Frontiers in Built Environment     Open Access  
Frontiers of Structural and Civil Engineering     Hybrid Journal   (Followers: 6)
Geomaterials     Open Access   (Followers: 4)
Geosystem Engineering     Hybrid Journal   (Followers: 1)
Geotechnik     Hybrid Journal   (Followers: 3)
Géotechnique Letters     Hybrid Journal   (Followers: 6)
HBRC Journal     Open Access   (Followers: 2)
Hormigón y Acero     Full-text available via subscription  
HVAC&R Research     Hybrid Journal  
Indoor and Built Environment     Hybrid Journal   (Followers: 2)
Infrastructure Asset Management     Hybrid Journal   (Followers: 2)
Infrastructures     Open Access  
Ingenio Magno     Open Access   (Followers: 1)
Insight - Non-Destructive Testing and Condition Monitoring     Full-text available via subscription   (Followers: 22)
International Journal for Service Learning in Engineering     Open Access  
International Journal of 3-D Information Modeling     Full-text available via subscription   (Followers: 3)
International Journal of Advanced Structural Engineering     Open Access   (Followers: 16)
International Journal of Civil, Mechanical and Energy Science     Open Access   (Followers: 1)
International Journal of Concrete Structures and Materials     Open Access   (Followers: 14)
International Journal of Condition Monitoring     Full-text available via subscription   (Followers: 2)
International Journal of Construction Engineering and Management     Open Access   (Followers: 9)
International Journal of Geo-Engineering     Open Access   (Followers: 3)
International Journal of Geosynthetics and Ground Engineering     Full-text available via subscription   (Followers: 4)
International Journal of Masonry Research and Innovation     Hybrid Journal   (Followers: 1)
International Journal of Pavement Research and Technology     Open Access   (Followers: 5)
International Journal of Protective Structures     Hybrid Journal   (Followers: 6)
International Journal of Steel Structures     Hybrid Journal   (Followers: 2)
International Journal of Structural Engineering     Hybrid Journal   (Followers: 10)
International Journal of Structural Integrity     Hybrid Journal   (Followers: 2)
International Journal of Structural Stability and Dynamics     Hybrid Journal   (Followers: 7)
International Journal of Sustainable Built Environment     Open Access   (Followers: 4)
International Journal of Sustainable Construction Engineering and Technology     Open Access   (Followers: 8)
International Journal on Pavement Engineering & Asphalt Technology     Open Access   (Followers: 6)
International Journal Sustainable Construction & Design     Open Access  
Journal of Bridge Engineering     Full-text available via subscription   (Followers: 15)
Journal of Building Engineering     Hybrid Journal   (Followers: 1)
Journal of Building Materials and Structures     Open Access   (Followers: 2)
Journal of Building Performance Simulation     Hybrid Journal   (Followers: 6)
Journal of Civil Engineering and Construction Technology     Open Access   (Followers: 12)
Journal of Civil Engineering and Management     Hybrid Journal   (Followers: 7)
Journal of Civil Engineering and Science     Open Access   (Followers: 7)
Journal of Civil Engineering Research     Open Access   (Followers: 6)
Journal of Civil Society     Hybrid Journal   (Followers: 4)
Journal of Civil Structural Health Monitoring     Hybrid Journal   (Followers: 4)
Journal of Composites for Construction     Full-text available via subscription   (Followers: 13)
Journal of Computing in Civil Engineering     Full-text available via subscription   (Followers: 24)
Journal of Construction Engineering     Open Access   (Followers: 7)
Journal of Construction Engineering and Management     Full-text available via subscription   (Followers: 19)
Journal of Constructional Steel Research     Hybrid Journal   (Followers: 8)
Journal of Earth Sciences and Geotechnical Engineering     Open Access   (Followers: 4)
Journal of Fluids and Structures     Hybrid Journal   (Followers: 6)
Journal of Frontiers in Construction Engineering     Open Access   (Followers: 2)
Journal of Green Building     Full-text available via subscription   (Followers: 11)
Journal of Highway and Transportation Research and Development (English Edition)     Full-text available via subscription   (Followers: 13)
Journal of Infrastructure Systems     Full-text available via subscription   (Followers: 21)
Journal of Legal Affairs and Dispute Resolution in Engineering and Construction     Full-text available via subscription   (Followers: 5)
Journal of Marine Science and Engineering     Open Access   (Followers: 1)
Journal of Materials and Engineering Structures     Open Access   (Followers: 5)
Journal of Materials in Civil Engineering     Full-text available via subscription   (Followers: 10)
Journal of Nondestructive Evaluation     Hybrid Journal   (Followers: 11)
Journal of Performance of Constructed Facilities     Full-text available via subscription   (Followers: 4)
Journal of Pipeline Systems Engineering and Practice     Full-text available via subscription   (Followers: 7)
Journal of Rehabilitation in Civil Engineering     Open Access   (Followers: 3)
Journal of Solid Waste Technology and Management     Full-text available via subscription   (Followers: 1)
Journal of Structural Engineering     Full-text available via subscription   (Followers: 40)
Journal of Structural Fire Engineering     Full-text available via subscription   (Followers: 6)
Journal of Sustainable Architecture and Civil Engineering     Open Access   (Followers: 3)
Journal of Sustainable Design and Applied Research in Innovative Engineering of the Built Environment     Open Access   (Followers: 1)
Journal of the Civil Engineering Forum     Open Access  
Journal of the South African Institution of Civil Engineering     Open Access   (Followers: 4)
Jurnal Spektran     Open Access   (Followers: 1)
Jurnal Teknik Sipil dan Perencanaan     Open Access   (Followers: 1)
Konstruksia     Open Access  
KSCE Journal of Civil Engineering     Hybrid Journal   (Followers: 2)
Latin American Journal of Solids and Structures     Open Access   (Followers: 4)
Materiales de Construcción     Open Access  
Mathematical Modelling in Civil Engineering     Open Access   (Followers: 3)
Nondestructive Testing And Evaluation     Hybrid Journal   (Followers: 17)
Obras y Proyectos     Open Access   (Followers: 1)
Open Journal of Civil Engineering     Open Access   (Followers: 7)
Photonics and Nanostructures - Fundamentals and Applications     Hybrid Journal   (Followers: 2)
Practice Periodical on Structural Design and Construction     Full-text available via subscription   (Followers: 4)
Proceedings of the Institution of Civil Engineers - Bridge Engineering     Hybrid Journal   (Followers: 7)
Proceedings of the Institution of Civil Engineers - Civil Engineering     Hybrid Journal   (Followers: 11)
Proceedings of the Institution of Civil Engineers - Management, Procurement and Law     Hybrid Journal   (Followers: 8)
Proceedings of the Institution of Civil Engineers - Municipal Engineer     Hybrid Journal   (Followers: 3)
Proceedings of the Institution of Civil Engineers - Structures and Buildings     Hybrid Journal   (Followers: 4)
Random Structures and Algorithms     Hybrid Journal   (Followers: 5)
Research in Nondestructive Evaluation     Hybrid Journal   (Followers: 7)
Revista IBRACON de Estruturas e Materiais     Open Access   (Followers: 1)
Road Materials and Pavement Design     Hybrid Journal   (Followers: 10)
Russian Journal of Nondestructive Testing     Hybrid Journal   (Followers: 6)
Science and Engineering of Composite Materials     Hybrid Journal   (Followers: 61)
Selected Scientific Papers - Journal of Civil Engineering     Open Access   (Followers: 3)
Slovak Journal of Civil Engineering     Open Access   (Followers: 2)
Soils and foundations     Full-text available via subscription   (Followers: 4)
Steel Construction - Design and Research     Hybrid Journal   (Followers: 3)
Structural and Multidisciplinary Optimization     Hybrid Journal   (Followers: 9)
Structural Concrete     Hybrid Journal   (Followers: 11)
Structural Control and Health Monitoring     Hybrid Journal   (Followers: 9)
Structural Engineering International     Full-text available via subscription   (Followers: 11)
Structural Safety     Hybrid Journal   (Followers: 7)
Structural Survey     Hybrid Journal  
Structure     Full-text available via subscription   (Followers: 23)
Structure and Infrastructure Engineering: Maintenance, Management, Life-Cycle Design and Performance     Hybrid Journal   (Followers: 13)
Structures     Hybrid Journal   (Followers: 1)
Study of Civil Engineering and Architecture     Open Access   (Followers: 8)
Superlattices and Microstructures     Hybrid Journal   (Followers: 2)
Surface Innovations     Hybrid Journal  
Technical Report Civil and Architectural Engineering     Open Access  
Teknik     Open Access  
The IES Journal Part A: Civil & Structural Engineering     Hybrid Journal   (Followers: 6)
The Structural Design of Tall and Special Buildings     Hybrid Journal   (Followers: 6)
Thin Films and Nanostructures     Full-text available via subscription   (Followers: 2)
Thin-Walled Structures     Hybrid Journal   (Followers: 4)
Transactions of the VŠB - Technical University of Ostrava. Construction Series     Open Access   (Followers: 1)
Transportation Geotechnics     Full-text available via subscription   (Followers: 1)
Transportation Infrastructure Geotechnology     Hybrid Journal   (Followers: 8)
Underground Space     Open Access  
Water Science & Technology     Partially Free   (Followers: 25)
Water Science and Technology : Water Supply     Partially Free   (Followers: 22)

           

Journal Cover Cement and Concrete Composites
  [SJR: 3.017]   [H-I: 83]   [17 followers]  Follow
    
   Hybrid Journal Hybrid journal (It can contain Open Access articles)
   ISSN (Print) 0958-9465
   Published by Elsevier Homepage  [3048 journals]
  • Synergy assessment in hybrid Ultra-High Performance Fiber-Reinforced
           Concrete (UHP-FRC)
    • Abstract: Publication date: February 2018
      Source:Cement and Concrete Composites, Volume 86
      Author(s): Alessandro P. Fantilli, Sukmin Kwon, Hirozo Mihashi, Tomoya Nishiwaki
      Ultra-High Performance Fiber-Reinforced Concretes (UHP-FRC) subjected to uniaxial tensile loads are investigated in the present paper. The study comprises a new procedure to assess the effectiveness of the hybridization, herein obtained by reinforcing UHP-FRC with micro and macro steel fibers. A comprehensive experimental campaign is also performed on monofiber and hybrid UHP-FRC. In all the concretes, the distance between the cracks and the minimum fiber volume fraction, which produces strain hardening response and multiple cracking, are theoretically and experimentally evaluated. If the bond parameter of the macro-fibers is properly calculated, the results of the analytical model, in terms of crack-spacing vs. fiber volume fraction, are in good agreement with the test data. Moreover, to increase the number of the cracks, and to reduce crack spacing, the hybridization is suitable only when the amount of macro-fibers is within a well-defined range.

      PubDate: 2017-11-15T15:21:52Z
       
  • How do recycled concrete aggregates modify the shrinkage and self-healing
           properties'
    • Abstract: Publication date: February 2018
      Source:Cement and Concrete Composites, Volume 86
      Author(s): Sonagnon Medjigbodo, Ahmed Z. Bendimerad, Emmanuel Rozière, Ahmed Loukili
      This paper presents the main results of a research carried out to analyze the mechanical properties, intrinsic permeability, drying shrinkage, carbonation, and the self-healing potential of concrete incorporating recycled concrete aggregates. The recycled concrete mixtures were designed by replacing natural aggregates with 0%, 30%, and 100% of recycled concrete gravel (RG) and 30% of recycled concrete sand (RS). The water to equivalent binder ratio was kept constant and recycled concrete aggregates were initially at saturated surface dried (SSD) state. The contribution of the porosity of natural and recycled aggregates to the porosity of concrete was estimated to understand the evolution of the intrinsic permeability and the open porosity. At long term, the maximum variation of drying shrinkage magnitude due to recycled concrete gravels did not exceed 15%. The correlation between drying shrinkage and mass-loss through “drying depth” concept showed that recycled concrete aggregates are affected by drying as soon as concrete is exposed to desiccation. A good correlation between 1-day compressive strength and 18-month carbonation depth was observed. The recycled concrete aggregates presented a good potential for self-healing as the relative recovery of cracks reached up to 60%.

      PubDate: 2017-11-15T15:21:52Z
       
  • Impact performances of steel tube-confined recycled aggregate concrete
           (STCRAC) after exposure to elevated temperatures
    • Abstract: Publication date: February 2018
      Source:Cement and Concrete Composites, Volume 86
      Author(s): Wengui Li, Zhiyu Luo, Chengqing Wu, Wen Hui Duan
      The impact behaviours of steel tube-confined recycled aggregate concrete (STCRAC) following exposure to elevated temperatures of 20 °C, 200 °C, 500 °C and 700 °C were experimentally investigated using a 100 mm-diameter split Hopkinson pressure bar (SHPB). The recycled coarse aggregate (RCA) replacement ratios were set as 0, 50% and 100%. The effect of RCA replacement ratio and exposure temperature on the impact properties of STCRAC were analysed in terms of failure modes, stress-strain time history curve and dynamic increase factor (DIF). The results show that the fire-damaged STCRAC can maintain its integrity during impact load. However, there were evident degradations in the dynamic behaviour of STCRAC after exposure to high temperatures of 500 °C and 700 °C. The ultimate impact strength, impact secant modulus and residual impact strength of STCRAC obviously decreased because of the damage due to high temperature exposure. But the degradations of both the ultimate impact strength and impact secant modulus of STCRAC under impact loading were less severe than those under quasi-static loading. The remaining strength factor and the DIF tended to increase with the raise of the elevated temperatures. Overall, during the impact loading, the fire-deteriorated STCRAC exhibited excellent impact behaviour.

      PubDate: 2017-11-15T15:21:52Z
       
  • Comparison of glass powder and pulverized fuel ash for improving the water
           resistance of magnesium oxychloride cement
    • Abstract: Publication date: February 2018
      Source:Cement and Concrete Composites, Volume 86
      Author(s): Pingping He, Chi Sun Poon, Daniel C.W. Tsang
      The water resistance of magnesium oxychloride cement (MOC) incorporating glass powder (GP) and pulverized fuel ash (PFA) with and without CO2 curing was investigated in terms of the strength retention coefficient and the volume stability. The microstructure was studied using quantitative X-ray diffraction (QXRD), thermogravimetry (TG), scanning electron microscopy (SEM) and transmission electron microscopy (TEM). The results show that the effect of incorporating GP on the water resistance is much lower than that of PFA due to the lower pozzolanic activity of GP generating a lower amount of magnesium silica hydrate gel (M-S-H gel). The MOC incorporated with GP or PFA showed high water resistance after CO2 curing due to the higher quantity of amorphous gel that formed a much denser interlocking network.

      PubDate: 2017-11-15T15:21:52Z
       
  • Sensitivity of the rapid chloride conductivity index test to concrete
           quality and changes in various test parameters
    • Abstract: Publication date: February 2018
      Source:Cement and Concrete Composites, Volume 86
      Author(s): Mike Otieno
      This study assessed the robustness of the chloride conductivity test with respect to the effect of concrete quality on its sensitivity to selected test parameters. Experiments were carried out to assess the sensitivity of the test to changes in the following parameters: (i) test duration (10, 40 and 120 s), (ii) concentration of the NaCl solution (3M and 5M), and (iii) variation of capillary voltage (7, 10 and 15 V). Concrete test specimens were made using three w/b ratios (0.40, 0.50 and 0.60) and three binder types (CEM I 52.5N (PC – Portland cement), 70/30 PC/FA (FA – fly ash) and 50/50 PC/GGCS (GGCS – ground granulated Corex slag)). One parameter was varied at a time. The results show that concretes with high chloride conductivity index (CCI) values (>∼0.8 mS/cm) are generally sensitive to changes in concentration of NaCl solution, capillary voltage across the test specimen, and test duration. For such concretes, the CCI increases with increase in capillary voltage, CCI decreases with decrease in salt concentration while the effect of a longer testing duration on CCI appears to be random. Even though it is not stipulated in the test standard, this study recommends that the test duration (i.e. the duration the capillary voltage is passed across the specimen once the electrical circuit of the test set-up is closed) is limited to <10 s.

      PubDate: 2017-11-15T15:21:52Z
       
  • Numerical modeling of mechanical regain due to self-healing in cement
           based composites
    • Abstract: Publication date: Available online 11 November 2017
      Source:Cement and Concrete Composites
      Author(s): Giovanni Di Luzio, Liberato Ferrara, Visar Krelani
      Recently there has been an increasing interest in self-healing materials which have the ability to retrieve their physico-mechanical properties once the material is damaged. This paper presents a numerical model on the self-healing capacity of cementitious composites capable of simulating the recovery of mechanical properties of the damaged (cracked) material. The recent SMM (Solidification-Microprestress-Microplane model M4) model for concrete, which makes use of a modified microplane model M4 and the solidification-microprestress theory, is able to reproduce the concrete time-dependent behavior, e.g. creep, shrinkage, thermal deformation, aging, and cracking from early age up to several years. The moisture and heat fields, as well as the hydration degree, are obtained from the solution of a hygro-thermo-chemical problem which is coupled with the SMM model. This numerical framework is extended to incorporate the self-healing effects and, in particular, the effect of delayed cement hydration, which is the main cause of the self-healing for young concrete. The new update model can also simulate the effects of cracking on the permeability and the opposite restoring effect of the self-healing on the mechanical constitutive law, i.e. the microplane model. A numerical example is presented to validate the proposed computational model employing experimental data from a recent test series undertaken at Politecnico di Milano. The experimental campaign has dealt with a normal strength concrete, in which (by means of three-point-bending tests performed up to controlled crack opening and up to failure, respectively before and after exposure to different conditioning environments) the recovery of stiffness and load bearing capacity has been evaluated.

      PubDate: 2017-11-15T15:21:52Z
       
  • Effects of fibers and conventional reinforcement contents on fibers
           scaterring in prismatic bars
    • Abstract: Publication date: Available online 11 November 2017
      Source:Cement and Concrete Composites
      Author(s): Yuri S. Karinski, Avraham N. Dancygier
      This paper presents results from a second stage of an experimental study of the dependence of steel fibers distribution along RFC prismatic specimens on the conventional reinforcement ratio and on the total amount of fibers in the concrete mix. The experimental program included two types of prismatic specimens with 30- and 60- kg/m3 of hooked-end steel fibers. Each specimen was sawed into equal segments and the numbers of fibers appearing at the cross-sections were counted and used for a further statistical analysis. This analysis comprised calculations of the average value and standard deviation of a non-dimensional variable, which represents the distribution of the total steel along the specimen. They were used to calibrate a theoretical model, which had been previously proposed by the authors. The test results showed reasonable to good agreement with the theoretical model. A comparison between the results of the 30- and 60-kg/m3 fibers shows that as the conventional reinforcement ratio increases, the standard deviations for the different mixtures approach each other.

      PubDate: 2017-11-15T15:21:52Z
       
  • Development of sandwich panels combining Sisal Fiber-Cement Composites and
           Fiber-Reinforced Lightweight Concrete
    • Abstract: Publication date: Available online 10 November 2017
      Source:Cement and Concrete Composites
      Author(s): Cristina Frazão, Joaquim Barros, Romildo Toledo Filho, Saulo Ferreira, Delfina Gonçalves
      This research proposes the development of an innovative structural panels based on the use of thin outer layers of Sisal Fiber-Cement Composites (SiFCC) together with a core layer of Polypropylene Fiber-Reinforced Lightweight Concrete (PFRLC). The influence of sisal fibers was studied in two different ways, short sisal fibers (50 mm) randomly distributed in the matrix, and long unidirectional aligned sisal fibers (700 mm) applied by a cast hand layup technique. Lightweight aggregates and polypropylene fibers were used in the concrete layer forming the panel's core in order to reduce its density and improve its post-cracking tensile strength and energy absorption capacity. The behavior of the sandwich panels in four-point bending test is described, and the various failure mechanisms are reported. Mechanical properties of both SiFCC and PFRLC were obtained, which were also used in the numerical simulations. Pull-off tests were performed to evaluate the bond strength between the outer SiFCC layers and the core PFRLC. The results revealed that the long sisal fibers were more effective in terms of providing to the panel higher flexural capacity than when using short sisal fibers, long fibers ensured the development of a deflection hardening behavior followed by the formation of multiple cracks, while short sisal fibers promoted a softening response after cracking.

      PubDate: 2017-11-15T15:21:52Z
       
  • Interfacial transition zone of cement composites with steel furnace slag
           aggregates
    • Abstract: Publication date: Available online 10 November 2017
      Source:Cement and Concrete Composites
      Author(s): Alexander S. Brand, Jeffery R. Roesler
      As previous studies of mortar and concrete with steel furnace slag (SFS) aggregates have shown increases or decreases in the bulk mechanical properties, this study investigated the microstructural cause of these opposing trends through characterization of the interfacial transition zone (ITZ) with quantitative image analysis of backscatter electron micrographs. Three SFS types – basic oxygen furnace (BOF), electric arc furnace (EAF), EAF/ladle metallurgy furnace (EAF/LMF) – were examined as aggregates in a portland cement mortar. The ITZ size for all SFS mortar mixtures was similar, with the ITZ of BOF and EAF/LMF being slightly more porous than mortar mixtures with EAF or dolomite. Microstructural examinations of the SFS particle revealed that BOF and EAF/LMF aggregates have different outer and interior compositions, with the outer composition consisting of a porous layer, which likely contributes to the reduced strength relative to EAF. The imaging results demonstrated that the type of SFS and its spatial composition greatly influences the bulk properties of mortar and concrete, mainly as a function of porosity content in the ITZ and the outer layer and interior porosity of the SFS aggregate.

      PubDate: 2017-11-15T15:21:52Z
       
  • Chemical and mineralogical alterations of concrete subjected to chemical
           attacks in complex underground tunnel environments during 20–36 years
    • Abstract: Publication date: Available online 9 November 2017
      Source:Cement and Concrete Composites
      Author(s): Chen Li, Mengxue Wu, Qing Chen, Zhengwu Jiang
      This paper investigates the chemical and mineralogical alterations of concrete in underground tunnel structures built from 1980 to 1996, located on the China's east seashore. The underground water around the tunnels had once been treated to be not or little aggressive. However, the complex environments in the tunnels had increased the aggressiveness of certain ingredients, thus causing chemical attacks. The chlorides in the leakage underground water cause chloride attack, and the NaCl crystallizations on the surface of the C50 pre-cast concrete segments induce a deeper chloride contamination. When the concrete suffers flowing leakage water, calcium leaching also occurs, leading to decalcification and magnesium incorporation. Under this circumstance, C50 pre-cast concrete shows a higher resistance compared with C30 cast-in-place concrete, mainly due to the low water to binder ratio. Within the C30 cast-in-place concrete facing concentrated leakage water and NaCl crystallization, a strong magnesium chloride attack is observed. Besides the materials factors, the environmental factors, including the high concentrations of both chloride and magnesium ions, the removal timing of calcium ion, and the water saturation, are believed to take responsibility for the magnesium chloride attack.

      PubDate: 2017-11-15T15:21:52Z
       
  • Feasibility of using near-field microwave reflectometry for monitoring
           autogenous crack healing in cementitious materials
    • Abstract: Publication date: January 2018
      Source:Cement and Concrete Composites, Volume 85
      Author(s): Iman Mehdipour, Reza Zoughi, Kamal H. Khayat
      This study demonstrates the feasibility of using the near-field microwave reflectometry technique to nondestructively monitor the evolution of autogenous crack healing of mortar containing high volume of supplementary cementitious materials. Mortar samples were subjected to controlled compressive loading to generate cracks, and subsequently exposed to wetting/drying cycles to initiate the autogenous crack healing process. Test results indicate that cracked mortar samples exhibit higher point-to-point microwave reflection coefficient variations caused by cracking and moisture ingress (i.e., larger coefficient of variation (COV) values of magnitude of reflection coefficient, Γ , obtained from microwave reflectometry). When subjected to wetting/drying cycles, samples with higher crack healing capability are found to undergo less variation in microwave reflection coefficient. Based on the results for cracked samples, the COV trends obtained for microwave reflection properties can be divided into three parts as a function of wetting/drying cycles: part (I) corresponding to a significant point-to-point microwave reflection variations resulting from crack formation and moisture ingress after the first wetting/drying cycle; part (II) indicating the onset of the crack healing process identified by the reduction in the COV values; and part (III) representing slow-down of crack healing process for the regions exposed to microwave radiation as indicated by the relatively constant COV values during additional wetting/drying cycles. Such variations in microwave reflection properties can be linked to changes in moisture transport properties and subsequent crack healing process. To corroborate the microwave reflectometry results, concurrent ultrasonic measurements were conducted on the mortar samples during the self-healing process, and a good correlation was observed between the outcomes of these two test methods. The results of material characterization assessments including capillary water absorption, crack healing quantification, as well as X-ray diffraction and scanning electron microscopy of crack healing products were also used to quantify the crack healing evolution for the investigated mortar samples.

      PubDate: 2017-11-08T14:26:30Z
       
  • Application of 3D-DIC to characterize the effect of aggregate size and
           volume on non-uniform shrinkage strain distribution in concrete
    • Abstract: Publication date: Available online 7 November 2017
      Source:Cement and Concrete Composites
      Author(s): Yang Chen, Jiangxiong Wei, Haoliang Huang, Wen Jin, Qijun Yu
      To elucidate the effect of aggregate size and volume on the non-uniform strain distribution in concrete, drying shrinkage of mortar and concretes were determined with 3D digital image correlation (3D-DIC). The distribution of shrinkage displacements and strains in mortar and concrete were analyzed. The results show that 3D-DIC makes it possible to measure non-uniform displacement distributions initiated by shrinkage in mortar and concrete. The non-uniformity became more remarkable with drying time. The presence of aggregates larger than 5 mm in concrete have locally changed the displacement and strain fields. Aggregates within 5–25 mm make non-uniform strain of concrete more fluctuant, especially when the aggregate size is larger than 10 mm. The maximum and minimum principal strain distributions became more heterogeneous with decreasing volume of aggregates.

      PubDate: 2017-11-08T14:26:30Z
       
  • Effect of fiber geometric property on rate dependent flexural behavior of
           ultra-high-performance cementitious composite
    • Abstract: Publication date: Available online 6 November 2017
      Source:Cement and Concrete Composites
      Author(s): Doo-Yeol Yoo, Nemkumar Banthia, Jin-Young Lee, Young-Soo Yoon
      In order to examine the rate dependent flexural performance of ultra-high-performance cementitious composite (UHPCC), a number of UHPCC beams containing three straight steel fibers with different aspect ratios of 65, 97.5, and 100 and one twisted steel fiber with an aspect ratio of 100 were fabricated and tested under quasi-static and impact loadings. Test results indicated that the use of long straight and twisted steel fibers resulted in improved quasi-static flexural performance, and their effectiveness was higher at large deflections. The twisted steel fiber was most effective at improving the deflection capacity and the number of micro-cracks under quasi-static flexural loading. In contrast, long straight steel fibers were more favorable than twisted steel fibers in terms of impact resistance and residual performance after impact damage. A lower sensitivity of the strain rate to the dynamic increase factor (DIF) was obtained for the post-cracking flexural strength than for the first-cracking strength, and the use of twisted steel fibers led to lower sensitivity to the strain rate on the DIF of post-cracking strength than that of straight ones. Finally, the higher strength concrete was less sensitive to the strain rate than the lower strength concrete.

      PubDate: 2017-11-08T14:26:30Z
       
  • Hot-pressed geopolymer: Dual effects of heat and curing time
    • Abstract: Publication date: Available online 6 November 2017
      Source:Cement and Concrete Composites
      Author(s): Navid Ranjbar, Amin Kashefi, Mahmoud R. Maheri
      Hot-pressed curing of geopolymers introduces an efficient fabrication of almost pore-less and high strength binders with a minimum usage of alkali activator in an extremely short time. This study presents the dual effects of temperature and curing time on kinetics and mechanical properties of VA-based hot-pressing geopolymer. Moreover, the effects of elevated temperature on the aluminosilicate precursors dissolution and the pressure loss of the hot-pressed geopolymer are investigated. It is observed that increment in temperatures and time improves the dissolving trends of the aluminosilicates. Furthermore, pressure loss of the hot-pressing system is associated with the liquid phase removal and gelation of particles; and, a successive repressing of mixture to the initial condition reduces the porosity of the matrix significantly. The increase in curing temperature of the hot-pressing system is the key point in acceleration of the geopolymerization kinetic, however, curing time is essential in stabilization of the reaction.

      PubDate: 2017-11-08T14:26:30Z
       
  • Applying a biodeposition layer to increase the bond of a repair mortar on
           a mortar substrate
    • Abstract: Publication date: Available online 4 November 2017
      Source:Cement and Concrete Composites
      Author(s): D. Snoeck, J. Wang, D.P. Bentz, N. De Belie
      One of the major concerns in infrastructure repair is a sufficient bond between the substrate and the repair material, especially for the long-term performance and durability of the repaired structure. In this study, the bond of the repair material on the mortar substrate is promoted via the biodeposition of a calcium carbonate layer by a ureolytic bacterium. X-ray diffraction and scanning electron microscopy were used to examine the interfaces between the repair material and the substrate, as well as the polymorph of the deposited calcium carbonate. The approximately 50 μm thick biodeposition film on the mortar surface mostly consisted of calcite and vaterite. Both the repair material and the substrate tended to show a good adherence to that layer. The bond, as assessed by slant shear specimen testing, was improved by the presence of the biodeposition layer. A further increase was found when engineering the substrate surface using a structured pattern layer of biodeposition.

      PubDate: 2017-11-08T14:26:30Z
       
  • Compressive strength and microstructure of alkali-activated fly ash/slag
           binders at high temperature
    • Abstract: Publication date: Available online 31 October 2017
      Source:Cement and Concrete Composites
      Author(s): Z. Pan, Z. Tao, Y.F. Cao, R. Wuhrer, T. Murphy
      This paper reports the results of the compressive strength and microstructure of various alkali-activated binders at elevated temperatures of 300 and 600 °C. The binders were prepared by alkali-activated low calcium fly ash/ground granulated blast-furnace slag at ratios of 100/0, 50/50, 10/90 and 0/100 wt.%. Specimens free of loading were heated to a pre-fixed temperature by keeping the furnace temperature constant until the specimens reached a steady state. Then the specimen was loaded to failure while hot. XRD, SEM and FTIR techniques were used to investigate the microstructural changes after the thermal exposure. The fly ash-based specimen shows an increase in strength at 600 °C. On the other hand, the slag-based specimen gives the worst high-temperature performance particularly at a temperature of 300 °C as compared to ordinary Portland cement binder. This contrasting behaviour of binders is due to their different binder formulation which gives rise to various phase transformations at elevated temperatures. The effects of these transformations on the compressive strength are discussed on the basis of experimental results.

      PubDate: 2017-11-02T13:58:14Z
       
  • A maturity approach to estimate compressive strength development of
           CO2-cured concrete blocks
    • Abstract: Publication date: Available online 28 October 2017
      Source:Cement and Concrete Composites
      Author(s): Dongxing Xuan, Baojian Zhan, Chi Sun Poon
      An alternative CO2 curing method for precast concrete products has been proposed in order to achieve rapid strength development at early age, as well as to capture and store greenhouse gas (CO2). In this paper, an experimental study for the development of a maturity approach is presented to estimate the strength development of carbonated concrete blocks. In order to promote the use of industrial flue gas containing CO2, a flow-through CO2 curing regime at ambient pressure and temperature was employed using different atmospheric conditions, such as various CO2 concentrations, RH values and gas flow rates. The experimental results showed that the compressive strength or maturity of the carbonated concrete blocks was affected by two factors: accelerated cement hydration and carbonation extent. A high CO2 concentration, a fast gas flow rate and a moderate relative humidity are essential for enhancing the maturity and the strength development. The developed model based on the maturity approach may accurately predict the strength development of the carbonated concrete blocks.

      PubDate: 2017-11-02T13:58:14Z
       
  • Mechanical properties of ambient cured high strength hybrid steel and
           synthetic fibers reinforced geopolymer composites
    • Abstract: Publication date: Available online 27 October 2017
      Source:Cement and Concrete Composites
      Author(s): Musaad Zaheer Nazir Khan, Yifei Hao, Hong Hao, Faiz Uddin Ahmed Shaikh
      Ambient cured geopolymer offers significant promise to the construction world as a possible alternative to ordinary Portland cement (OPC). However, as a member of the ceramic family, geopolymers exhibit extremely brittle behaviour. The inclusion of short discrete fibers is an effective way to enhance their ductility. In this research, a series of fiber combinations and volume fractions between steel fibers with end-hooked or spiraled and synthetic fibers (made of high strength polyethylene (HSPE)) were incorporated in a high strength ambient cured geopolymer matrix. The performance of synthesized geopolymer composites was compared in terms of fresh and hardened state properties, such as workability, uniaxial compressive strength, modulus of elasticity, Poisson's ratio, flexural tensile strength, energy absorption capacity and post-peak residual strength etc. The interfacial bond between the spiral steel fiber and the geopolymer matrix as well as fiber distribution in the composites were assessed through individual fiber-pull out tests and physical examination of the cast samples, respectively. The test results show that the addition of fibers significantly improved the load carrying capacity of the composites under flexure load, i.e. increased from 3.89 MPa to 11.30 MPa together with an improved behaviour in compression. In general, all fiber reinforced composites displayed a stable deflection hardening response and multiple-cracking failure mode. Moreover, among composites with different fiber volume fractions, the composite having 1.60% steel+0.40% HSPE showed the highest ultimate flexure strength, correspondingly the highest energy absorption capacity. The individual fiber pull-out test curves ascertained a strong bonding between the geopolymer mortar and spiral-steel fiber.

      PubDate: 2017-11-02T13:58:14Z
       
  • IFC - Editorial board
    • Abstract: Publication date: November 2017
      Source:Cement and Concrete Composites, Volume 84


      PubDate: 2017-10-25T22:15:36Z
       
  • Influential factors in volume change measurements for cementitious
           materials at early ages and in isothermal conditions
    • Abstract: Publication date: Available online 25 October 2017
      Source:Cement and Concrete Composites
      Author(s): Lavinia Stefan, Claude Boulay, Jean-Michel Torrenti, Benoît Bissonnette, Farid Benboudjema
      Early age deformations, when restrained, lead to an increase of cracking risk of the material, especially in the case of high strength materials to which we apply modern high energy mixing techniques which accelerate initial hydration rate. The experimental campaign aims to investigate and understand the differences not yet explained between several autogenous measurement techniques, such as the initial swelling measured by the linear devices that is not observed in the case of volumetric measurements. The differences between the results obtained by means of devices when values are zeroed at setting time can be imputed to the intrinsic behaviour of the material within the well-defined boundary conditions imposed by the molds, and not only to the measurement artefact.

      PubDate: 2017-10-25T22:15:36Z
       
  • Immobilization of copper indium selenide solar module waste in concrete
           constructions
    • Abstract: Publication date: Available online 24 October 2017
      Source:Cement and Concrete Composites
      Author(s): Gintautas Skripkiūnas, Saulius Vasarevičius, Vaidotas Danila
      The aim of this study was to investigate the properties of concrete containing various quantities of copper indium selenide (CIS) solar module waste by replacing a certain part (up to 40%) of sand. The obtained results have shown that an increase in the content of solar module waste resulted in an increase of the density of fresh and hardened concrete. The compressive strength of the specimens compared to the control specimens has been higher, when sand aggregate was replaced by CIS solar module waste particles from 5 to 20%. Also, in all cases a decrease in the water absorption and porosity of concrete specimens containing immobilized waste compared to those with no waste has been observed. The leaching behaviour of the concrete containing immobilized waste was also studied. The results showed that the concrete with sand aggregate replacement by waste particles between 5 and 10% has the best leaching properties. That replacement can be used for CIS solar module waste recycling in concrete production.

      PubDate: 2017-10-25T22:15:36Z
       
  • Decoupling the autogenous swelling from the self-desiccation deformation
           in early age concrete with mineral additions: Micro-macro observations and
           unified modelling
    • Abstract: Publication date: Available online 23 October 2017
      Source:Cement and Concrete Composites
      Author(s): Jérôme Carette, Shiju Joseph, Özlem Cizer, Stéphanie Staquet


      PubDate: 2017-10-25T22:15:36Z
       
  • Model for practical prediction of natural carbonation in reinforced
           concrete: Part 1-formulation
    • Abstract: Publication date: Available online 20 October 2017
      Source:Cement and Concrete Composites
      Author(s): Stephen O. Ekolu
      A model is proposed for prediction of natural carbonation in reinforced concrete (RC) structures, and is potentially applicable to existing and new RC structures. The major components of the model comprise mathematical functions applied to predict the influence of concrete composition, and environmental factors on natural carbonation. This paper introduces the model concept and explains its structure including derivation, optimization and calibration. Over 163 data sets taken from a 10-year carbonation study were used in the model development and calibration. Only the experimental data that were based on outdoor natural exposure environment were employed in this research. Also in this study, the proposed model is compared with fib-Model Code 2010 using carbonation predictions generated from 346 data sets involving real world, highway structures. It is shown that the proposed model is comparably accurate and involves mainly basic tests with no major anticipated costs.

      PubDate: 2017-10-25T22:15:36Z
       
  • Age-dependent size effect and fracture characteristics of ultra-high
           performance concrete
    • Abstract: Publication date: January 2018
      Source:Cement and Concrete Composites, Volume 85
      Author(s): Lin Wan-Wendner, Roman Wan-Wendner, Gianluca Cusatis
      This paper presents an investigation of the age-dependent size effect and fracture characteristics of ultra-high performance concrete (UHPC). The study is based on a unique set of experimental data connecting aging tests for two curing protocols of one size and size effect tests of one age. Both aging and size effect studies are performed on notched three-point bending tests. Experimental data are augmented by state-of-the-art simulations employing a recently developed discrete early-age computational framework. The framework is constructed by coupling a hygro-thermo-chemical (HTC) model and the Lattice Discrete Particle Model (LDPM) through a set of aging functions. The HTC component allows taking into account variable curing conditions and predicts the maturity of concrete. The mechanical component, LDPM, simulates the failure behavior of concrete at the length scale of major heterogeneities. After careful calibration and validation, the mesoscale HTC-LDPM model is uniquely posed to perform predictive simulations. The ultimate flexural strengths from experiments and simulations are analyzed by the cohesive size effect curves (CSEC) method, and the classical size effect law (SEL). The fracture energies obtained by LDPM, CSEC, SEL, and cohesive crack analyses are compared, and an aging formulation for fracture properties is proposed. Based on experiments, simulations, and size-effect analyses, the age-dependence of size effect and the robustness of analytical-size effect methods are evaluated.

      PubDate: 2017-10-18T21:36:04Z
       
  • Chemical self-healing system with novel microcapsules for corrosion
           inhibition of rebar in concrete
    • Abstract: Publication date: January 2018
      Source:Cement and Concrete Composites, Volume 85
      Author(s): Biqin Dong, Weijian Ding, Shaofeng Qin, Ningxu Han, Guohao Fang, Yuqing Liu, Feng Xing, Shuxian Hong
      Two kinds of chemically-triggered self-healing systems with novel microcapsules are designed to protect rebar from corrosion in concrete. X-ray micro-computed tomography (XCT) method is employed to non-destructively visualize the protection performance and quantitatively evaluate the efficacy of the self-healing system in a wet-dry cyclic accelerating corrosion test. Environmental scanning electron microscopy (ESEM) system equipped with texture element analysis microscopy (TEAM) is used to verify the results of XCT imaging analysis. The results reveal that the self-healing system-high efficiency is achieved by delaying the depassivation of the rebar and reducing the corrosion rate.

      PubDate: 2017-10-18T21:36:04Z
       
  • Pore-scale modeling of chloride ion diffusion in cement microstructures
    • Abstract: Publication date: January 2018
      Source:Cement and Concrete Composites, Volume 85
      Author(s): Yuankai Yang, Moran Wang
      Understanding the mechanism of chloride ion diffusion in cement is significant to improve the reliability of offshore reinforced concrete structures. The chloride ionic diffusivity in cement-based microstructures is predicted by pore-scale modeling using a modified lattice Boltzmann method. Both the Nernst-Planck equation for ion diffusion and the Poisson equation for electrodynamic effect are fully solved. The predicted effective diffusivities in cement-based microstructures with different porosities are in good agreements with the experiment data. The results show that the pore size distribution and Zeta potential of cement-based microstructures directly influence the effective diffusivities of chloride ions. The cement-based microstructure with smaller pore size and higher negative Zeta potential hinders chloride ions corrosion more effectively. The electrokinetic effect on the chloride ionic transport is negligible when the ratio of the maximum-probability pore size and the Debye length is higher than 32 in the cement-based microstructure. For engineering applications, we provide a predictive and easy-to-use formula by up-scaling to correlate the effective chloride ion diffusivity with electrokinetic effect in cement paste.

      PubDate: 2017-10-18T21:36:04Z
       
  • Alkali-activated slag concrete: Fresh and hardened behaviour
    • Abstract: Publication date: January 2018
      Source:Cement and Concrete Composites, Volume 85
      Author(s): F. Puertas, B. González-Fonteboa, I. González-Taboada, M.M. Alonso, M. Torres-Carrasco, G. Rojo, F. Martínez-Abella
      The behaviour of fresh and hardened alkali-activated slag (AAS) and OPC concretes was compared and the effect of mixing time assessed. OPC and AAS concrete slump and rheological results proved to differ, particularly when the slag was activated with waterglass (WG). The nature of the alkaline activator was the key determinant in AAS concrete rheology. Bingham models afforded a good fit to all the OPC and AAS concretes. In OPC and NaOH-activated AAS concretes, longer mixing had an adverse effect on rheology while improving hardened performance only slightly. In WG-AAS concrete, longer mixing times, improved mechanical properties and also rheological behaviour was enhanced, in which those conditions were required to break down the microstructure. Longer mixing raised thixotropy in OPC and NaOH-activated AAS concretes, but lowered the value of this parameter in waterglass-activated slag concrete.

      PubDate: 2017-10-11T06:59:00Z
       
  • A time-variant model of surface chloride build-up for improved service
           life predictions
    • Abstract: Publication date: November 2017
      Source:Cement and Concrete Composites, Volume 84
      Author(s): Mahmoud Shakouri, David Trejo
      Current service life models for predicting the time to chloride-induced corrosion initiation of steel reinforcement in concrete structures are based on a hypothesized surface chloride concentration, C s , as a boundary condition. This is either assumed to be constant or varies with time, generally disregarding other factors that influence C s . For example, Fickian models use a constant C s and existing time-variant models assume C s is only a function of time. In this paper, an improved time-variant C s model is hypothesized using general physical concepts and is then validated by an empirical study. The proposed model, as opposed to the existing time-variant models, not only accounts for the variability of C s with exposure time but also incorporates the effects of time to exposure and the effects of the concentration of chlorides in the exposure environment. The model assumes that C s is sigmoidal in shape with an asymptote that is a function of the concentration of chlorides in the environment. The input variables for the proposed model were selected based on best subset sampling analysis on the results of the experimental work to determine the influence of water-to-cement ratio, time to exposure, the concentration of chlorides in the exposure environment, and exposure time on C s . The accuracy of the proposed model is assessed versus existing time-variant C s models and the results indicate that the proposed model better predicts the C s in concrete exposed to chlorides. Moreover, results of service life predictions using the proposed model show that the proposed model yields more accurate results, better protecting owners from financial and engineering risks.

      PubDate: 2017-10-11T06:59:00Z
       
  • Susceptibility of Portland cement and blended cement concretes to plastic
           shrinkage cracking
    • Abstract: Publication date: Available online 4 October 2017
      Source:Cement and Concrete Composites
      Author(s): Sadegh Ghourchian, Mateusz Wyrzykowski, Luis Baquerizo, Pietro Lura
      The market share of different types of blended cements is increasing year by year. Generally, blended cements are ground to higher fineness and exhibit a slower development of mechanical properties compared to Ordinary Portland Cement (OPC), which might affect the concrete performance in terms of shrinkage cracking at early ages. In this paper, the performance of concretes made with different cement types are compared according to the ASTM C1579-13 standard for plastic shrinkage cracking. The cracking behavior was further correlated to the deformations of both unrestrained and restrained specimens measured by a 3D image correlation system. The main factors influencing the cracking behavior were discussed based on poromechanics. It is concluded that the bulk modulus evolution has a dominant effect on controlling the plastic shrinkage cracking. Concretes made of more reactive cements, in particular with higher clinker content, are less susceptible to plastic shrinkage cracking. For cements with the same clinker content, increasing the cement fineness reduces the risk of plastic shrinkage cracking.

      PubDate: 2017-10-11T06:59:00Z
       
  • Passivity of embedded reinforcement in carbonated low-calcium fly
           ash-based geopolymer concrete
    • Abstract: Publication date: Available online 4 October 2017
      Source:Cement and Concrete Composites
      Author(s): Mahdi Babaee, M.S.H. Khan, Arnaud Castel
      This paper investigates the carbonation of two low-calcium fly ash-based geopolymer concretes to assess the effect of alkali concentration in the activator, and the carbon dioxide concentration on the pH drop and passivity of the reinforcement. Chemical adsorption of carbon dioxide at different concentrations into an aqueous NaOH solution, as representative of the pore solution, is studied to predict the distribution of carbonate species and pH drop. pH profiles were obtained during the exposure period. X-ray diffraction (XRD) was conducted to identify the carbonate phases. Half-cell potential and polarization resistance of reinforced concrete samples were monitored to assess the passivity of embedded reinforcement. The carbonated binders remained rather highly alkaline during the accelerated carbonation test which was in agreement with the predicted values. No sign of depassivation of reinforcement was observed, even for the lower strength grade concrete, during the long exposure time of 500 days to 1% carbon dioxide.

      PubDate: 2017-10-11T06:59:00Z
       
  • Effect of internal water content on carbonation progress in cement-treated
           sand and effect of carbonation on compressive strength
    • Abstract: Publication date: Available online 3 October 2017
      Source:Cement and Concrete Composites
      Author(s): Lanh Si Ho, Kenichiro Nakarai, Yuko Ogawa, Takashi Sasaki, Minoru Morioka
      This study investigates the effect of internal water content in cement-treated sand on carbonation progress and the effect of carbonation on compressive strength. To alter the internal water content, specimens were cured under three conditions: sealed, drying, and water sprayed. The carbonation coefficient, which was determined by a phenolphthalein spray test, decreased as the internal water content increased because of water sprayed. However, a thermal analysis revealed that the amounts of portlandite consumed and calcium carbonate generated by carbonation exhibited dissimilar trends: the amount of generated calcium carbonate was the maximum when there was a small increase in water content by water sprayed. Further increments in water content significantly lowered the amount of generated calcium carbonate. The measured compressive strength increased linearly with the amount of calcium carbonate. This implies that the amount of calcium carbonate is a good indicator of the effect of carbonation on the strength development of cement-treated sand and that both these quantities are affected by the internal water content.

      PubDate: 2017-10-03T17:48:26Z
       
  • Nanoindentation study of the interfacial zone between cellulose fiber and
           cement matrix in extruded composites
    • Abstract: Publication date: Available online 3 October 2017
      Source:Cement and Concrete Composites
      Author(s): R.S. Teixeira, G.H.D. Tonoli, S.F. Santos, E. Rayon, V. Amigó, H. Savastano, F.A. Rocco Lahr
      The present study shows the application of the nanoindentation technique to evaluate the properties of the cellulose fiber-cement matrix interfacial zone in composites prepared with an auger extruder. The degree of strength of the bond between fiber and matrix is recognized as important variable that influences macro-mechanical properties, such as modulus of rupture and toughness of cement based composites. The nanoindentation measurements showed the highest hardness and elastic modulus in the part inner of the cellulosic fiber after hydration process due to precipitation and re-precipitation of cement hydration products. These results indicate that mineralization of the cellulosic fibers can affect the stress distribution and interfacial bond strength in the cement based composite.

      PubDate: 2017-10-03T17:48:26Z
       
  • A combined SPM/NI/EDS method to quantify properties of inner and outer
           C-S-H in OPC and slag-blended cement pastes
    • Abstract: Publication date: Available online 3 October 2017
      Source:Cement and Concrete Composites
      Author(s): Y. Wei, X. Gao, S. Liang
      To identify the distinct microstructural features and to provide insight into the mechanism by which the phases in hardened paste possess, this study adopts the coupled techniques of quantitative modulus mapping in the form of Scanning Probe Microscopy (SPM) images, nanoindentation (NI), and energy-dispersive X-ray spectroscopy (EDS) for comprehensive investigation on the chemical-mechanical-morphological properties of C-S-H gel in both ordinary Portland cement (OPC) and slag-blended cement pastes. The thickness of the inner C-S-H (IP) layer is precisely measured for the first time by modulus mapping, it varies with the types of unreacted cores as well as the addition of the supplementary cementitious materials. An interface transition zone (ITZ) is found between the unreacted C3S grain and the surrounding inner C-S-H layer. The mechanical properties of the five types of C-S-H in OPC and the slag-blended pastes are not significantly affected by their chemical compositions. A good correlation between the storage modulus and the indentation modulus of the individual phases is found. The results indicate the significance of SPM-based modulus mapping technique as a powerful tool to characterize the phase in cementitious materials with more attractive features of higher spatial resolution.

      PubDate: 2017-10-03T17:48:26Z
       
  • Effect of chloride content on mechanical properties of ultra high
           performance concrete
    • Abstract: Publication date: November 2017
      Source:Cement and Concrete Composites, Volume 84
      Author(s): Sukhoon Pyo, Million Tafesse, Heeae Kim, Hyeong-Ki Kim
      Experimental results on the effects of chloride content of ultra high performance concrete (UHPC) are presented. The experimental variables are the amount of sodium chloride, ranging from zero to 3.0% per cement weight, and matrix strength, including normal mortar and high strength mortar. Sodium chloride is directly mixed with cement matrix in order to simulate harsh environments by promoting the corrosions of fibers and matrix. The effects of chloride content are evaluated in terms of visual observation, electrical resistivity change, compressive strength, bending strength, and dynamic Young's modulus. The experimental results show that UHPC has the superior capability to resist chloride ions due to its dense microstructures, which prevent the growth of rust crystals. Furthermore, the experimental findings suggest that the potentials for corrosion of steel fibers and for corrosion-induced matrix cracking are inconsequential in UHPC even if chloride ions penetrate into UHPC.

      PubDate: 2017-09-25T17:23:44Z
       
  • Incorporating phase change materials in concrete pavement to melt snow and
           ice
    • Abstract: Publication date: November 2017
      Source:Cement and Concrete Composites, Volume 84
      Author(s): Yaghoob Farnam, Hadi S. Esmaeeli, Pablo D. Zavattieri, John Haddock, Jason Weiss
      This paper discusses the use of phase change materials (PCM) in concrete pavement as a method to store energy which can be used as a heat source during cooling events to melt ice/snow. The experimental program includes: (1) use of low-temperature differential scanning calorimetry to evaluate thermal properties of PCM, and (2) use of large-scale concrete slabs containing PCM to evaluate the ability of the PCM concrete to melt snow on the surface of the concrete pavement. The temperature in the concrete slabs and the snow melting rate were monitored as quantitative measurements of the efficiency of the PCM in the concrete. In addition, time-lapse images were taken. Two approaches were used to incorporate PCM in concrete: placing the PCM in lightweight aggregate (LWA) which was then mixed into the concrete, and placing the PCM in embedded metal pipes embedded in the slab during concrete casting. In this study, paraffin oil was use as a PCM that is effective in releasing heat near the freezing temperature of PCM when the PCM undergoes a phase transformation from liquid to solid. The heat released during the phase transformation can melt ice and snow on the concrete pavement surface. The results indicate that incorporating PCM in concrete pavement is not only feasible, but also practical.

      PubDate: 2017-09-19T16:57:32Z
       
  • Eco-efficient ultra-high performance concrete development by means of
           response surface methodology
    • Abstract: Publication date: November 2017
      Source:Cement and Concrete Composites, Volume 84
      Author(s): Iman Ferdosian, Aires Camões
      The research described in this paper represents a statistically based model with the help of response surface methodology (RSM) aiming to study the applicability of this method to ultra-high performance concrete (UHPC) mixture design and its optimization. Besides, the effects of silica fume, ultra-fine fly ash (UFFA) and sand as three main variable constituents of UHPC on workability and compressive strength as the main performance criteria and responses of this high-tech material were investigated. The models proposed here demonstrate a perfect correlation among variables and responses. Furthermore, through performing a multi-objective optimization, cement and silica fume, as two main constituents of UHPC affecting its eco-efficiency and cost, were substituted by UFFA and sand as much as possible. Finally, an eco-efficient UHPC with cement and silica fume content of 640 kg/m3 and 56.3 kg/m3 respectively and compressive strength and flow diameter of 160.3 MPa and 19 cm was developed.

      PubDate: 2017-09-19T16:57:32Z
       
  • Comparative performance of alkali activated slag/metakaolin cement pastes
           exposed to high temperatures
    • Abstract: Publication date: November 2017
      Source:Cement and Concrete Composites, Volume 84
      Author(s): Oswaldo Burciaga-Díaz, José Iván Escalante-García
      This paper presents a study on the effect of temperature exposure of binders of blast furnace slag (BFS) and metakaolin (MK) in BFS-MK weight ratios of 100-0, 50-50, and 0-100 activated with sodium silicate of modulus Ms = SiO2/Na2O = 1 and 5, 10 and 15% Na2O. A blended ordinary CPC-30R Portland cement reference was used. Pastes were subjected to exposure up to 1200 °C and the performance was evaluated in terms of compressive strength, residual strength, volumetric shrinkage, physical appearance and microstructural changes at different temperatures. All the binders retained more than 30 MPa after exposure to 800 °C for 4 h; specimens of MK and CPC-30R experienced the highest strength losses of 42 and 56% respectively, while those of 100-0 and 50-50 showed minor losses of ∼20%. After heating at 1200 °C the samples showed microstructural damage and more than 65% of strength losses. XRD indicated that the 100-0 and 50/50 binders are prone to form crystalline phases as akermanite, nepheline and nosean at temperatures greater than 1000 °C, while 0-100 geopolymeric binders preserved mostly an amorphous structure even at 1200 °C with some traces of mullite. The dehydration of C-A-S-H and N-A-S-H altogether with the crystallization of the binder gel induced the formation of highly porous microstructures.

      PubDate: 2017-09-19T16:57:32Z
       
  • Use of pre-wetted lightweight fine expanded shale aggregates as internal
           nutrient reservoirs for microorganisms in bio-mineralized mortar
    • Abstract: Publication date: November 2017
      Source:Cement and Concrete Composites, Volume 84
      Author(s): Zeynep Başaran Bundur, Mary Jo Kirisits, Raissa Douglas Ferron
      Interest in developing bio-based self-healing cement-based materials has gained broader attention in the concrete community. One of challenges in developing bio-based self-healing cement-based materials is that cell death or insufficient metabolic activity might occur when the cells are inoculated to the cement paste. This paper investigates the use of internal nutrient reservoirs via pre-wetted lightweight fine expanded shale aggregates to improve cell viability in mortar. Incorporation of internal nutrient reservoirs resulted in an increase in the vegetative cells remaining without any substantial loss in strength. These results pave the way to develop a self-healing and self-curing concrete with an extended service life.

      PubDate: 2017-09-19T16:57:32Z
       
  • Optimization of normal and high strength recycled aggregate concrete
           mixtures by using packing model
    • Abstract: Publication date: November 2017
      Source:Cement and Concrete Composites, Volume 84
      Author(s): Mayara Amario, Caroline Santana Rangel, Marco Pepe, Romildo Dias Toledo Filho
      This paper analyzes the possibility of applying the Compressible Packing Model (CPM) for the proportion of concrete mixtures produced with Recycled Concrete Aggregates (RCAs). As a matter of fact, the RCAs are composed of natural aggregates and attached mortar and, as a consequence, they generally present a higher porosity in comparison with ordinary natural aggregates. The higher porosity of RCAs can affect the resulting Recycled Aggregate Concretes (RACs) properties and, for this reason, the mix design procedure available in literature for ordinary concrete mixture cannot be applied as such in the case of RACs. In this context, the present work first presents a preliminary study in which the optimal mixing procedure for RACs is investigated and then, a possible extension of the CPM in the case of RACs is analyzed. Several structural RAC mixtures were designed for three strength classes (25, 45 and 65 MPa) by considering the variation of the aggregate replacement from 0 to 100%. Finally, the proposed procedure is experimentally validated by performing mechanical and durability tests on selected mixtures for the three strength classes with a RCAs content up to 60%. The results reported herein demonstrate the applicability of the CPM for recycled concrete mixtures and highlight as the rational use of RCAs lead to produce structural RAC without affecting its mechanical and the durability performance.

      PubDate: 2017-09-13T20:39:58Z
       
  • Greening effect in slag cement materials
    • Abstract: Publication date: November 2017
      Source:Cement and Concrete Composites, Volume 84
      Author(s): Domitille Le Cornec, Qirong Wang, Laurence Galoisy, Guillaume Renaudin, Laurent Izoret, Georges Calas
      This article presents the first spectroscopic data describing the processes responsible for the temporary blue-green coloration that forms during the hydration of various materials containing Ground Granulated Blast-furnace Slag (GGBS) under anoxic conditions. UV-visible-near infrared Diffuse Reflectance (DR) spectra demonstrate a striking similarity of the coloring center forming during the curing of a broad range of GGBS-bearing materials (pure GGBS with different compositions, mix Portland cement/GGBS (30/70), concrete and mortar). All spectra are similar to those of polysulfide complexes contained in the interlayer spacing of a synthetic green-colored hydrated calcium aluminate phase (AFm). This “greening effect” demonstrates a progressive oxidation of sulfide-based compounds initially contained in these materials during curing of GGBS bearing materials.

      PubDate: 2017-09-13T20:39:58Z
       
  • Material characterisation of macro synthetic fibre reinforced concrete
    • Abstract: Publication date: November 2017
      Source:Cement and Concrete Composites, Volume 84
      Author(s): Ali Amin, Stephen J. Foster, R. Ian Gilbert, Walter Kaufmann
      In this paper, the post cracking behaviour of macro synthetic polypropylene fibre reinforced concrete is investigated through a series of matched tests that measure tension directly through uniaxial tension tests and indirectly through prism bending and determinate round panel tests. An analytical model previously developed by the authors for the determination of the residual tensile strength provided by steel fibres in prism bending tests is adapted for the round panel tests and is shown to correlate well with the collected experimental data.

      PubDate: 2017-09-13T20:39:58Z
       
  • Assessment of pore structure evolution in the limestone calcined clay
           cementitious system and its implications for performance
    • Abstract: Publication date: November 2017
      Source:Cement and Concrete Composites, Volume 84
      Author(s): Yuvaraj Dhandapani, Manu Santhanam
      Use of limestone and calcined clay together for clinker substitution makes an effective low clinker cement blend, which shows promising mechanical properties at early ages. The performance of these cementitious systems strongly depends on the pore structure, which is a dominant factor governing the durability characteristics because of its direct influence on the transport properties. The experimental study described in this paper on three different binder systems including Ordinary Portland Cement, Portland Pozzolana Cement - with 30% Type F Fly Ash (designated FA30) - and Limestone Calcined Clay Cement (LC3) pastes shows that the LC3 system attains greater refinement of the pore structure as early as 3 days, as seen from mercury intrusion porosimetry. Electrical measurements also reveal lower conductivity in the system, which suggests better resistance to ionic transport in the binder phase. The results of hydrate phase assemblage studied by X-ray diffraction also indicate that greater amount of hydrates contribute in a major way to the reduction in the (water-filled) porosity in all the systems. This change occurs at varying rates for the different systems due to the difference in hydration characteristics. The estimated permeability suggests that the LC3 binder system attains much lower permeability compared to the ordinary Portland cement and FA30. A comparison of the formation factor shows distinct differences in the microstructural development and suggests a more durable binder with LC3 cementitious system.

      PubDate: 2017-09-07T20:37:36Z
       
  • Acoustic characterization of damage and healing of
           microencapsulation-based self-healing cement matrices
    • Abstract: Publication date: November 2017
      Source:Cement and Concrete Composites, Volume 84
      Author(s): Wenting Li, Zhengwu Jiang, Zhenghong Yang
      Self-healing of cracks in cementitious composites is of great significance to improve the serviceability of concrete structures. In this study, poly urea–formaldehyde (PUF) microcapsules enclosing epoxy resins were synthesized. The damage- and healing process of cement paste incorporating microcapsules was in situ detected by acoustic emission (AE) technique, in which passive AE and active AE were combined to provide complementary information about the damage and crack formation. The two representative AE signals, i.e., matrix cracking and debonding of the interface, were used as calibration for further AE post-processing analysis. The effects of the concentration of microcapsules and the level of pre-damage were investigated. The results revealed the distinguished cracking mechanisms according to the differentiated feature of the signals in terms of the temporal and spectral AE descriptors. The plot of average frequency (AF) versus RA index (rise time/amplitude) confirms that the cracking modes contribute to the characteristic spectrum.

      PubDate: 2017-09-07T20:37:36Z
       
  • Damage model for simulating chloride concentration in reinforced concrete
           with internal cracks
    • Abstract: Publication date: November 2017
      Source:Cement and Concrete Composites, Volume 84
      Author(s): Mao Kurumatani, Hisashi Anzo, Kenji Kobayashi, Shinichiro Okazaki, Sohichi Hirose
      We present a method to simulate, in three dimensions, the concentration of chloride ions that penetrate into concrete with internal cracks. The method comprises the crack-propagation analysis of concrete and the diffusion analysis of chloride ions. A finite-element model with a damage model that is based on fracture mechanics for concrete was applied in the crack-propagation analysis, and we were able to reproduce the three-dimensional geometry of the internal cracks. Chloride-ion transfer through internal cracks was simulated by diffusion analysis with the simultaneous consideration of damage, and a diffusion coefficient that was expressed as a function of the damage variable obtained from crack-propagation analysis. We present a formulation of crack-propagation analysis by using the damage model and unsteady-diffusion analysis in consideration of damage. We also present a verification analysis of internal cracking in concrete to demonstrate that the crack width and the chloride concentration can be evaluated without mesh dependency. This is followed by a validation analysis. A comparison between the numerical and experimental results shows that the proposed method enables the high-accuracy simulation of chloride penetration into concrete with internal cracks.

      PubDate: 2017-09-07T20:37:36Z
       
  • Pressure-sensitive properties of emulsion modified graphene
           nanoplatelets/cement composites
    • Abstract: Publication date: November 2017
      Source:Cement and Concrete Composites, Volume 84
      Author(s): Jiaming Xu, Dong Zhang
      Graphene nanoplatelets(GNP)/cement composites were prepared using three types of GNP with different structures. In order to investigate the effects of GNP and styrene-acrylate emulsion on properties of GNP/cement composites, GNP with different addition (0-2.0 wt%) and styrene-acrylate emulsion (10 wt%) were mixed into cement through the method of mechanical stirring. Electrical performance and the pressure-sensitive property of GNP/cement composites were studied. The results showed that the addition of GNP to cement would lead to a significant drop of resistivity and make composites manifest pressure sensitivity. In addition, the structure (C/O atomic ratio) of GNP greatly affected the properties of the GNP/cement composites. A distinct enhancement in pressure sensitivity was found when emulsion was added to GNP/cement composites. The gauge factor of emulsion modified GNP/cement composites reached a peak value of 7.783, which was 1 order of magnitude higher than composites without emulsion. This work offered a new opportunity to make use of traditional cement materials combining with GNP.

      PubDate: 2017-09-07T20:37:36Z
       
  • Effects of CaCl2 on hydration and properties of lime(CaO)-activated
           slag/fly ash binder
    • Abstract: Publication date: Available online 5 September 2017
      Source:Cement and Concrete Composites
      Author(s): Woo Sung Yum, Yeonung Jeong, Seyoon Yoon, Dongho Jeon, Yubin Jun, Jae Eun Oh
      This study presented CaCl2 as a potential additive activator to develop a new strong, price-competitive CaO-activated GGBFS binder blended with fly ash (CAS 4:4:2) to commercially replace ternary blended cements, which generally consist of 40% Portland cement, 40% GGBFS, and 20% fly ash (wt.%) (PC 4:4:2), widely used for concrete production. Despite CAS 4:4:2 having no clinker cement compound, the addition of CaCl2 not only significantly accelerated reactions of CAS 4:4:2 binders but also largely increased strengths at all curing days. Up to 72 h, the cumulative reaction heat of CAS 4:4:2 with CaCl2 was also reasonably low. Reaction products and microstructures of hardened CAS 4:4:2 pastes were considerably changed after CaCl2 addition. The CaCl2 presence markedly promoted dissolution of the glass phase of GGBFS and fly ash in early days, resulting in more production of reaction products (e.g., C-S-H, hydrocalumite) and pore-size refinement.

      PubDate: 2017-09-07T20:37:36Z
       
  • Chloride binding capacity of pastes influenced by carbonation under three
           conditions
    • Abstract: Publication date: November 2017
      Source:Cement and Concrete Composites, Volume 84
      Author(s): Honglei Chang
      This research investigates the influence of carbonation on chloride binding capacity under three conditions varying in the sequence and way of carbonation-chloride contact: I, hardened pastes first carbonated then contacted with chloride; II, hardened pastes first contacted with chloride then carbonated; III, pastes inner-introduced with chloride during casting, hardened and then carbonated. The results indicate that, before carbonation, the bound chloride content of pastes inner-introduced with chloride is slightly higher than that of pastes first hardened then contacted with chloride because more Friedel's salt is formed through the former way. And during the carbonation process, the remaining bound chloride content mainly depends on the content of un-carbonated C-S-H gel. And based on the content of it before total carbonation, the content of residual bound chloride in samples under condition I is higher than that under the other two conditions after the same carbonation time. After complete carbonation, the bound chloride content under the three conditions all approximates to zero, which indicates that carbonation makes paste lose chloride binding capacity completely.

      PubDate: 2017-09-01T20:35:21Z
       
  • Using ultrasonic wave reflection to monitor false set of cement paste
    • Abstract: Publication date: November 2017
      Source:Cement and Concrete Composites, Volume 84
      Author(s): Chul-Woo Chung, Prannoy Suraneni, John S. Popovics, Leslie J. Struble
      The standard mechanical penetration approach for monitoring cement paste stiffening (Vicat needle method, ASTM C191) does not distinguish responses associated with false set of cement paste caused by secondary gypsum formation. The objective of this research is to determine whether ultrasonic wave reflection, using a testing set up with high measurement sensitivity, could be used to monitor false set of cement paste. Penetration resistance, P-wave, and S-wave reflection coefficients were measured on cement pastes with water-to-cement ratio 0.5. The S-wave reflection coefficient showed a sharp and abrupt linear drop associated with secondary gypsum formation, thereby indicating that S-wave ultrasonic wave reflection can be used to monitor false set of cement pastes. False set could not be distinguished in penetration resistance or P-wave UWR test data.

      PubDate: 2017-09-01T20:35:21Z
       
  • Alkali resistant glass fiber reinforced concrete: Pull-out investigation
           of interphase behavior under quasi-static and high rate loading
    • Abstract: Publication date: November 2017
      Source:Cement and Concrete Composites, Volume 84
      Author(s): Christina Scheffler, Serge Zhandarov, Edith Mäder
      Single fiber model composites of alkali resistant (AR-) glass fibers and a cementitious matrix were used to investigate the pull-out behavior under quasi-static and high speed loading. For fundamental understanding of the effect of the fiber/matrix interphase on the pull-out behavior under impact, differently sized AR-glass fibers were spun. As a first approach, the fiber surface was modified in oppositional ways using the following sizings: one based on a polypropylene (PP, weak) film former and another one based on a styrene-butadiene (strong) film former. Additionally, some of the fibers were kept unsized for comparison. A new ‘alternative’ approach was employed to determine the local interfacial shear strength, τ d , and the critical energy release rate, G ic , from the reliable force values of the force–displacement curves. For all fiber surface states, the τ d and G ic values for high loading rates appeared to be considerably greater than the corresponding parameters for a quasi-static pull-out test. This can be explained using a model based on Zhurkov's kinetic (thermal fluctuation) theory of the strength of solids, which also enabled to estimate the apparent activation energy for interfacial debonding. Both quasi-static and high-rate pull-out tests on this fiber/matrix pair can be considered as ‘normal’ (slip-dependent interfacial friction was not observed) and their results can be evaluated using the described approaches. The interfacial frictional stress reduced at high-rate pull-out tests for all systems. One of the possible mechanisms responsible for this behavior may be the smoothing of surface asperities upon debonding. As revealed by AFM of fracture surfaces, in the case of unsized fibers or those with the ‘strong’ styrene–butadiene sizing, the interfacial crack occurs through surface layers of the matrix material adjacent to the fiber, but it may propagate through the weak interface when the fiber is sized with ‘weak’ PP film former.

      PubDate: 2017-09-01T20:35:21Z
       
  • Effects of coarser fine aggregate on tensile properties of ultra high
           performance concrete
    • Abstract: Publication date: November 2017
      Source:Cement and Concrete Composites, Volume 84
      Author(s): Sukhoon Pyo, Hyeong-Ki Kim, Bang Yeon Lee
      This experimental research investigates the mechanical properties and shrinkage of ultra high performance concrete (UHPC) incorporating coarser fine aggregates with maximum particle size of 5 mm. To adequately design UHPC mixtures using various sizes of solid constituents, particle packing theory was adopted. UHPC mixtures containing either dolomite or basalt, and four fiber volume fractions up to two volume percent were investigated. Uniaxial tension test was performed to evaluate the first cracking tensile strength, ultimate tensile strength, tensile strain capacity and cracking pattern. The UHPC mixtures with dolomite and steel fibers with more than one volume percent achieved more than 150 MPa of compressive strength at the age of 56 days, and showed strain hardening behavior and limited decrease in tensile strength compared to typical UHPC without coarser fine aggregates. The experimental results highlight the potential of dolomite used as coarser fine aggregate in UHPC.

      PubDate: 2017-09-01T20:35:21Z
       
 
 
JournalTOCs
School of Mathematical and Computer Sciences
Heriot-Watt University
Edinburgh, EH14 4AS, UK
Email: journaltocs@hw.ac.uk
Tel: +00 44 (0)131 4513762
Fax: +00 44 (0)131 4513327
 
Home (Search)
Subjects A-Z
Publishers A-Z
Customise
APIs
Your IP address: 54.224.187.45
 
About JournalTOCs
API
Help
News (blog, publications)
JournalTOCs on Twitter   JournalTOCs on Facebook

JournalTOCs © 2009-2016