JournalTOCs

Challenge Journal of Concrete Research Letters
Number of Followers: 5

This is an Open Access Journal

Open Access journal
ISSN (Online) 2548-0928
Published by ISSR Journals

[3 journals]

Performance of light weight ferrocement composite walls
- Authors: Yousry Bauomy I. Shaheen; Zeinab Abd El khaleq Etman, Doha Elmetwally Abdelmonem Kandil
  Abstract: The aim of this research is to examine the performance of reinforced lightweight ferrocement walls under vertical and horizontal loading. The walls were made up of two thin layers of ferrocement reinforced with one, two, three, or four layers of welded wire mesh or expanded steel mesh. The panels’ core was constructed of lightweight extruded foam. An experimental program of thirteen lightweight walls with total dimensions of 100x650x1250 mm was casted to achieve this goal and tested until failure. ABAQUS finite-element package was conducted. The parameters in this study were the kind of reinforcement; welded and expanded wire meshes, the steel bars, and. the number of layers of steel mesh. Ultimate load, mode of failure, initial cracking load, service load, energy absorption, and ductility ratio were calculated and observation to evaluate the findings. The findings displayed that the performance of the ferrocement walls reinforced with expanded wire meshes is better than that of the walls reinforced with welded wire meshes. The energy absorbed increased by 40 % for specimens reinforced with expanded wire meshes is more than that of the walls reinforced with welded wire a good agreement was observed among the theoretical and experimental observations. This paper highlights uses of employing light weight ferrocement units in building of economic housing, which is particularly valuable for both developed and developing nations, with significant frugal benefits.
  PubDate: Fri, 15 Sep 2023 15:23:03 +030
Evaluation of the lightweight foamed concrete characteristics
- Authors: Zeinab A. Etman; Samar A. Rokbah
  Abstract: The purpose of this paper is to assess the properties of light weight foamed concrete. In this research, two phases are investigated. The first stage explored the characteristics of fresh and hardened foamed concrete using a foaming agent. The following parameters were employed in this study: foaming agent used as a volume of concrete mix by 10, 20, and 40%, fly ash used as a replacement of cement content by 10, 25, and 50%, and polypropylene fiber used with varied volume fractions of 0.5, 0.75, and 1.0%. Slump values are applied to evaluate the fresh properties. To evaluate the hardened concrete, the dry density and compressive strength at 7 and 28 days are computed. Furthermore, the 28-day tensile splitting strength and flexural strength are studied. The effect of a high temperature was evaluated. The second stage investigated the effects of polypropylene fiber on both fresh and hardened concrete. It was observed that foaming agents improve fresh characteristics while decreasing compressive strengths and dry density. Furthermore, utilizing fly ash improves the characteristics of both fresh and hardened foamed concrete. The fiber reduces the fresh characteristics while enhancing the toughened properties. Because of its low density, foamed concrete is being used for structural applications because of this study. Such as those utilized for thermal insulation, acoustic impedance, and fire breaks. Also used to create road foundations for roads built on soft soil.
  PubDate: Fri, 15 Sep 2023 15:23:03 +030
Mechanical, durability and solar reflectance properties of colored
self‒compacting concrete
- Authors: Sadık Alper Yıldızel
  Abstract: Urbanized areas are known to have significantly higher temperatures than rural areas. The Urban Heat Island (UHI) effect is caused by surfaces such as asphalt, buildings, and other heat-absorbing surfaces that store more heat than natural vegetation. Sunlight reflecting properties of building materials are improved with different applications. The present study investigates the mechanical, durability and solar reflectance properties of the colored self-compacting concrete. SCCs containing yellow, green, and black pigments were produced and evaluated. The fresh properties were determined with the slump, L-Box and V-funnel tests. Furthermore, compressive strength, solar reflectance and magnesium sulfate resistance tests were conducted. Yellow pigment added SCC showed a great potential (with the albedo of 0.42) in terms of solar reflectance and decreasing the contribution to the urban heat island effect.
  PubDate: Fri, 15 Sep 2023 15:23:03 +030
Cover & Contents Vol.14 No.3
- Authors: Journal Management CJCRL
  PubDate: Fri, 15 Sep 2023 15:23:02 +030
Chemical resistance of hardened mortar containing andesite and marble
industry waste powder
- Authors: İsmail İsa Atabey; Serhat Çelikten, Mehmet Canbaz
  Abstract: The sludge generated during forming processes of marble and andesite rocks is kept in dust form after drying. Due to the high consumption of andesite and marble, the storage and health problems of these dusts arise. Therefore, reducing the environmental impacts of waste and recovering them for the economy is an important issue. For this purpose, in this work, mortar specimens were manufactured using 0%, 5%, 10%, 15% and 20% of waste marble and andesite powders separately by Portland cement. Strength properties of the samples were investigated before and after immersion to the hydrochloric acid (HCl), sodium sulfate (Na2SO4) and magnesium sulfate (MgSO4) solutions. The results indicated that partial substitution of Portland cement by andesite and marble powder up to 10% have positive influence on the mechanical properties of the mortars at ambient conditions. In addition, the andesite incorporated mortars have the better performance under the acid and sulfate environments than the other mortars. On the other hand, substitution of Portland cement by marble powder more than 5% has negative influence on the chemical resistance of the mortars.
  PubDate: Tue, 20 Jun 2023 17:48:18 +030
Efficacies of suggested strength-based prediction models for estimation of
compressive and tensile properties of normal concrete
- Authors: Mukunda Matada Nalina
  Abstract: One of the most crucial challenges faced by today’s construction industry for a speedy delivery is undeniably the ‘time-factor’ accompanied by promised quality within the framework of distinct budget. Strength based - Prediction models helps in estimating the early strengths as well as later-stage strength or strength at any age of concrete. Such models assist the structural and execution engineers in arriving at a fair judgement of compressive strength of concrete. A normal practice usually followed by the material testing laboratories and quality assurance cell at site is to assess the cube compressive strength of concrete which is an intrinsic engineering property governing the design and performance phase of structures. It is found from the literature that most of the prediction models that are formulated to estimate the compressive strength of concrete at any age are actually based on cylinder compressive strength of concrete. Therefore, this paper attempts to use some of the suggested prediction models with two sets of data, that is, one by considering experimental results of cube compressive strength found at the age of 7, 14 and 28-days and two by utilizing a conversion value, suitable cylinder compressive strength is obtained. These datasets are thoroughly used in the prediction models to accurately estimate the compressive strength of concrete. Similarly, appropriate prediction models are sought to determine the split tensile strength of normal concretes based on cubic compressive strength and cylinder compressive strength. Particularly, results of the present study showcase that although the prediction models are developed based on cylinder compressive strength, they can agreeably be used on cube strength data as the ratio of (Pi/Ai) obtained is the higher range of 0.85-1.00 and with only an early cube strength result, it is possible to predict an accurate value of split tensile strength of concrete at an age of 28-days. The effectiveness of suggested prediction models through statistical parameters are determined and their efficiencies are found to be in the higher range of 94% to 98%.
  PubDate: Tue, 20 Jun 2023 17:48:18 +030
Use of crushed bricks and recycled concrete as replacement for fine and
coarse aggregates for sustainable concrete production
- Authors: Alaa Abdeltawab Aboalella; Abeer Elmalky
  Abstract: The growing concern over the significant ecological changes requires sustainable developments in all fields. Concrete production is one of the largest consumers of natural resources as it consumes a huge volume of natural fine and coarse aggregates, which constitute 70% - 80% of the concrete volume. It is evident that such large amount of concrete production in the growing construction industry puts significant impact on the use of natural resources and the environment. Hence, investigating the use of recycled materials to replace the finite natural resources became evident and is the focus of researchers. In this research, the use of waste crushed bricks (CB), and crushed recycled concrete (CRC) as a partial replacement of fine and coarse aggregates in concrete was studied. The replacement ratios of 10%, 50%, and 100% by weight of either fine or coarse aggregates were used. Eight concrete mixes with 168 specimens were tested for compressive, splitting tensile as well as, flexural strength. All tests were carried out at ages of 7, 28 and 56 days. The results indicated that there is a feasibility of using bricks and concrete wastes in concrete mix as a partial replacement of course and fine aggregates. It is deduced that a 50% replacement ratio of coarse aggregate with crushed concrete resulted in a 30%, 25%, and 23% increase in compressive, tensile, and flexural strengths, respectively. While 50% replacement ratio of fine aggregate with crushed bricks resulted in a 23%, 28%, and 19% increase in compressive, tensile, and flexural strengths, respectively. The most effective mix was at 50% replacement ratio of coarse aggregate with crushed concrete in combination with 50% replacement ratio of fine aggregate with crushed bricks. The results of this mix showed 32%, 28%, 26% increase in compressive, tensile, and flexural strengths, respectively.
  PubDate: Tue, 20 Jun 2023 17:48:18 +030
Cover & Contents Vol.14 No.2
- Authors: Journal Management CJCRL
  PubDate: Tue, 20 Jun 2023 17:48:17 +030
Optimization of reinforced concrete frame structures and matrix
displacement method
- Authors: Muhammed Çoşut; Gebrail Bekdaş, Sinan Melih Nigdeli
  Abstract: In this study, reinforced concrete frame system is generated, and all structural elements which are beam and columns are optimized according to the applied distributed loads and different concrete classes by using Matlab program. Jaya algorithm which is a Metaheuristic Algorithm that enables to optimization process and finds the best cross sections, reinforcement area as well as cost of the system, is proposed. It is observed that cross-section, reinforced area as well as cost of the system are changed when concrete classes are used differently. After finding the optimum design values for frame system, the matrix displacement method is utilized to specify the system displacements and all nodes forces. Furthermore, columns and beam displacement results are not similar, and also internal forces are different for nodes. TS500 (2000) (Reinforced concrete structures design and construction rules) and TBDY (2018) (Turkey Building Earthquake Regulation) are used together to specify variables, constraints and also necessity values. The proposed method is feasible for frame structures consisting of different members.
  PubDate: Tue, 07 Mar 2023 16:29:34 +030
Cause of distress of an old building through analytical and
micro‒analytical methods ‒ a case study
- Authors: Rajappan Preetha; Kalpana Kumari, Balakrishnan Sakthi, Chandrasekharan Nair Harikumar, Haneef Ibrahim Abdul Gani
  Abstract: The case study pertains to the methods such as nondestructive, semi-destructive, chemical, electrochemical and micro-analytical, utilized to assess the cause of cracking and spallation of a reinforced concrete building near to the eastern coastline of India. Cause of degradation of the structure is assessed to arrive at the appropriate repair methodology. From the analysis methods, direct cause of failure could not be attributed to a single cause since many factors co-exist such as structural cracking, carbonation and presence of chloride and the synergistic effect; hence concludes that an appropriate repair methodology has to be evolved to address each issue.
  PubDate: Tue, 07 Mar 2023 16:29:34 +030
Cover & Contents Vol.14 No.1
- Authors: Journal Management CJCRL
  PubDate: Tue, 07 Mar 2023 16:29:34 +030
Axial compression behaviour of concrete-filled auxetic tubular short
columns
- Authors: Kemal Solak; Süleyman Nazif Orhan
  Abstract: Concrete-filled steel columns (CFSCs) are of great interest in the literature as they are capable of carrying higher loads by combining the exceptional qualities of steel and concrete. With auxetic materials being introduced to civil engineering applications, the influence of these materials on CFSCs remains a matter of curiosity. The current study implements a nonlinear finite element analysis to evaluate the performance of circular CFSCs with six auxetic tubes under axial compression and the proposed numerical model was validated using published experimental data. The effect of the auxetic steel tube’s porosity and Poisson’s ratio on CFSCs was examined parametrically in terms of ultimate strength using the confined concrete model. Moreover, the stress distributions of the concrete and the auxetic steel tubes were also thoroughly examined. Based on the findings of the analysis, the ultimate load of CFSCs, utilising auxetic tubes with the same density and porosity but different Poisson’s ratio, increased proportionally with the increase of auxetic behaviour. When it comes to auxetic tubes with different densities and porosities, the influence of the Poisson’s ratio of the tubes diminished and the stiffness of tubes became more dominant over the mechanical characteristics of columns as the density of the auxetic steel tubes increased or decreased. The stiffness of the auxetic tubes reduced as porosity increased, as did the ultimate load of the columns. Additionally, the ultimate loads of the auxetic steel tube columns are found to be lower than those of bare steel tube columns filled with concrete due to perforations.
  PubDate: Tue, 07 Mar 2023 16:29:34 +030