Abstract: Publication date: Available online 19 May 2018Source: HBRC JournalAuthor(s): Yasser M. El-Sherbiny Manmade objects such as buildings, statues and other materials made from cement, brick and stone are subject to mechanical weathering. Windblown sand wears down sharp edges, causing loss of style, features and details. Heat and cold cause expansion cracks that permit water to enter, freeze and or expand, causing more damage.The aggressive environment of the North West coast of Egypt, including sea storms, streams sand to impingement the facades of the summer houses and causes severe staining, peeling and damage to the paints and finishes of the exterior. High maintenance cost of such houses may eventually discourage owners to maintain the style and the architectural integrity of the compounds and villages. Architectural designs utilizing appropriate building and finishing materials which resist the wear and erosion, caused by high speed sand and salt laden air carrying sand particles and sea water droplets, are of vital importance to reduce maintenance cost.This paper investigates the wear rates and erosion mechanism for different finishing materials such as plastic paints (Complico), artificial stone tiles, Pharos stones, Calcium Carbonate natural stones, and fired brick tiles. Tests showed considerable wear rates when the facades are oriented about 60 degrees from the local wind directions. The results indicate a superior performance for the fired brick tiles. Other materials may be used on facades with somewhat different orientations ranging between 45 and 70 degrees from the wind direction.
Abstract: Publication date: April 2018Source: HBRC Journal, Volume 14, Issue 1Author(s): Walid A. Attia, Masood M.M. Irheem Design of the structures to resist seismic force depends on the theory of dissipation in elastic energy that already exists in response modification factor “R-factor”. The main problem in codes gives a constant value for R-factor, since change in boundary conditions of building change in behavior of braced steel frame structures and that effects on R-factor. This study is an attempt to assess overstrength, ductility and response modification factor of X-braced steel frame under change in boundary conditions, as change in the direction of strong axis of column and connection support type of column besides variation in storey and bays numbers to be 21 frames and each frame has 8 different boundary conditions as sum of 168 cases for analysis. These frames were analyzed by using nonlinear static “pushover” analysis. As results of this study change in support type and direction of strong axis of column give large change in value of R-factor; the minimum value was 4.37 and maximum value 10.97. Minimum value is close to code value that’s mean the code is more conservative in suggesting of R-factor and gives a large factor of safety. Change in the location of bracing gives change in value of R-factor for all boundary conditions. Change in direction of strong axis of columns and support type didn’t give change in value of fundamental period, all boundary conditions.
Abstract: Publication date: April 2018Source: HBRC Journal, Volume 14, Issue 1Author(s): Baher I. Farahat, Khaled A. Osman Some movements within modern architecture particularly emphasize the importance of matching buildings to their surroundings. However, practicing such “contextual architecture” is highly challenging and typically not something the future inhabitants of a building are well equipped for participating in. This paper attempts to be a new vision to design an important building in such sensitive places, for example, designing a museum in a historical context. The methodology of the study is a qualitative method based on a theoretical foundation. It sheds light on the concepts and definition of museums and contextualism, and answers the main question proposed in this paper: “How can we design a huge and important building such as a museum in historical context while respecting its importance and at the same time avoiding the deterioration of this historical place'” And based on answering the sub following questions too: What is the museum concept' What are the activities and functions of this prototype' What is the museum form and morphology' What are the types of contextual design' What are the strategies of contextual design' This part ends with electing some criteria that will be used as basis for the practical part. And thus it can be concluded the ideal strategy for designing a museum in historical context. Discussion of the findings is expected to enrich the talk in that domain.
Abstract: Publication date: April 2018Source: HBRC Journal, Volume 14, Issue 1Author(s): Hossam Elbadry, Ashraf Eid Geotechnical engineers are still facing the true harmful problems of the very deep deposits of very soft clay soils for structural foundations. It is believed that the current used methods of geotechnical engineering improvement in soft clays are justified on the basis that pre-knowledge of the potential problems can lead to economic benefits if the planning, design, and construction of projects can be modified to suit the problems to provide increase of its strength, reduction of total and differential settlement, reasonable cost, and shorten construction time. Therefore, the cost-effective alternatives play significantly an essential role to evaluate considerably the efficiency among the widely used current methods in this true problematic field. From this considerable point, vast experience has been acquired to solve this problem through soft ground improvement before turning to deep foundations which need considerably huge cost especially for the very deep very soft ground. Unfortunately, the improvement magnitudes of the most widely used current techniques do not suit even fairly with their required cost and their installation difficulty which need highest level of accuracy.In this paper, innovative convenient type of foundation system has been laboratory tested to evaluate the significance through the aspect of cost-effective alternative which is clearly unachieved by the currently used techniques. This novel technique was achieved by high efficiency rate, simplicity for execution, huge increase of strength under footings, rapid rate of construction process, considerable saving in the required cost, and significantly reduce total and differential settlement.
Abstract: Publication date: April 2018Source: HBRC Journal, Volume 14, Issue 1Author(s): Mona B. Anwar The simplicity and low cost of the standard penetration test (SPT) have always been the major advantages of this test over other field tests. Despite that other field tests (e.g. PMT, CPT, DMT, …) are supposed to provide more reliable results, yet they are still costly and not feasible in every project. Considering that SPT is available in all site investigation programs for all sizes of project, it was tempting to provide correlations between SPT results and other field test results. Through these correlations it will be feasible to estimate the soil parameters and deformation properties from the SPT number of blows. However, it is believed that correlations will differ, if the tested soil is calcareous. Furthermore, adopting local correlations is more favorable as it caters for the geological formation of the site. In this research it is aimed to obtain correlation between the PMT results and the SPT results for calcareous soil. A site investigation comprising boreholes with SPT and PMT was carried out near to the Red sea coast in Jeddah. The study was carried out to develop a local correlation between the results of SPT and PMT considering the effects of soil gradation and carbonate content. Comparison between the obtained correlation and other available correlations is also considered.
Abstract: Publication date: April 2018Source: HBRC Journal, Volume 14, Issue 1Author(s): Mohammed H. Serror, Mohammed N. Abdelmoneam Despite the fact that steel is a ductile material, the significant damage, during earthquake events, highlighted the need to thoroughly investigate the seismic performance of steel structures. Seismic design procedures have been developed to enable structures to achieve specific acceptable level of damage under dynamic loads in accordance with particular levels of ductility. The ductility of steel moment resisting frames is developed through flexural yielding of beams, shear yielding of column panel zones, and flexural yielding of columns. Meanwhile, the frame must develop the required ductility without failure in the beam-to-column connection. The observations on panel zone behavior revealed that it can afford high ductility; however, localized deformations at corners of panel zone may increase the likelihood of fracture in vicinity of beam flange welds. On the other hand, the observations on flexural yielding behavior of columns reported potential soft story collapse. Consequently, counting on ductility due to shear yielding of panel zone and flexural yielding of columns is not recommended. Hence, the focus of this study has been directed toward flexural yielding of frame beams. The effect of beam profile slenderness (according to the Egyptian code design limits) has been examined against ductility, over-strength and redundancy with numerical assessment for the anticipated seismic force reduction factor. The reduction factor has been evaluated using both the N2-method and the time history analysis method. Accordingly, a guideline has been established for the Egyptian code provisions to enable professionals to assign the steel moment resisting frame between adequate-ductility, intermediate-ductility and limited-ductility.
Abstract: Publication date: April 2018Source: HBRC Journal, Volume 14, Issue 1Author(s): Bashir H. Osman, Erjun Wu, Bohai Ji, Suhaib S. Abdulhameed Carbon fiber reinforcement polymer (CFRP) sheets are the most commonly materials that are used to strengthen reinforced concrete members due to high strength-to-weight ratio, excellent mechanical strength, and good fatigue properties. In this research program seven reinforced concrete beams were tested under four points loading with different shear span-to-depth ratios avd, longitudinal and vertical reinforcement ratios. A numerical analysis using ANSYS software program was done by modeling 27 reinforced concrete beams with and without CFRP sheets. The beam dimensions, concrete strength, strengthening configuration of the CFRP sheets (full wrapped, U shape, and side bonding), and FRP thickness were considered as the main parameters of the numerical analysis. A comparison between the finite element (FE) results and the ACI standard code demonstrated the validity of the computational models in capturing the structural response of FRP contribution with variation varied from (10–16)%, (12–20)% and (13–19)% for full wrapping, U-jacketing, and side bonding, respectively. The finite element models were able to accurately predict the load capacities for the simulated RC beams strengthened in shear with CFRP composites. The results obtained using ANSYS finite element are relatively identical to the experimental ones, showing reasonable agreement with variation not more than 5% in all the specimens.
Abstract: Publication date: April 2018Source: HBRC Journal, Volume 14, Issue 1Author(s): Ghada M.F. Essa, Hossam M. Zakria, Tamer S. Mahmoud, Tarek A. Khalifa This paper studies the microstructure and microhardness of the welded joints of the annealed aluminum alloy AA7020-O produced by friction stir welding (FSW) technique. The material was applied to post weld heat treatment (solution treatment and artificially aged, T6). The traverse speed and the rotational speed are the most important process parameters of FSW, and have great influence on the heat input of the welding operation which governs the welded joints quality. To investigate their effect, the welding operation was performed using three traverse speeds, 20, 40 and 60 mm/s with two rotational speeds of 1125 and 1400 rpm, and other welding parameters were kept constant to produce comparable joints. It was found that the two rotational speeds are accepted with lower traverse speeds to produce sound joints. Microstructure of the welded joints was significantly affected by the FSW process parameters, and slight effect was reported for the grain size. Microhardness examination showed high weld joint quality with respect to the base metal hardness, which proves the reprecipitation of the hardening phase in the weld zone. The microhardness profile was strongly dependant on the rotational speed, and the average values of the joints hardness have increased with the decrease in the rotational speed, where it have been slightly affected by the welding speed.
Abstract: Publication date: April 2018Source: HBRC Journal, Volume 14, Issue 1Author(s): Mina Michel Samaan, Osama Farag, Magdi Khalil This article presents a case of heuristic optimization of cooling loads and daylighting levels in deep halls of Egyptian Universities, using DesignBuilder software, with EnergyPlus and Radiance engines, in order to show the vital role of simulation tools in architects’ hands. Generally speaking, campus buildings in Egypt reflect real problems of energy efficiency and indoor environmental quality of the overcrowded educational spaces. The case, studied in the article, is for three drawing halls of different specifications, located in the main building of the Faculty of Engineering at Mansoura University. The simulation work is processed along a road map of three consequent phases: simulating the existing situation of thermal and visual comfort inside the three halls; optimizing cooling loads by testing various alternatives of design parameters; and including daylighting levels in the optimization process. The study found that optimizing windows shading of overhangs and louvers, low-transmittance characteristics of glazing, and ventilation system would provide from 26% to 31% reduction of cooling loads compared to base case, without taking into account daylighting requirements. While, opening skylight strips, perpendicular to the external facade, with 8% window–roof-ratio, would provide required daylighting levels with minimum increase of cooling loads. The principle objective, attained through this article, is to underline the significance of using building performance simulation (BPS) tools in the architectural educational and research work.
Abstract: Publication date: April 2018Source: HBRC Journal, Volume 14, Issue 1Author(s): Yasser Abdelghany Fawzy This paper investigates the effect of recycled gravel obtained from low (Gl) or medium (Gm) concrete grade on fresh property of concrete (slump), mechanical properties (compressive-splitting tensile strength) and mass transport properties (ISAT-sorptivity) of concrete containing dolomite as a natural coarse aggregate. Concrete specimens were prepared with cement, water, sand and dolomite admixed with recycled gravel. The percentage of recycled gravel/dolomite was 0:100, 25:75, 50:50 and 75:25 at w/c = 0.50, 0.55 and 0.60. The effect of silica fume and bonding admixture at w/c = 0.55 on concrete properties were also considered. The results indicated that, increasing the percentage of recycled gravel/dolomite led to decreasing the slump. All mechanical properties of concrete discussed were inversely affected by increasing percentage of recycled gravel/dolomite from low and medium concrete. Adding 10% SF or bonding admixture increased the mechanical properties of concrete. Mass transport properties of concrete (ISAT-sorptivity) were enhanced by decreasing the percentage of recycled gravel/dolomite. The optimum percentage of recycled gravel/dolomite = 25%.
Abstract: Publication date: April 2018Source: HBRC Journal, Volume 14, Issue 1Author(s): Amal Kamal Mohamed Shamseldin A number of Environmental Assessment Methods of Buildings (EAMB) had emerged all over the world, and a number of global variables affect the estimation of the assessment item weights in those methods. Unifying the global common variables’ effect on estimating the weights of the assessment items of all different methods among the world for different time periods helps saving the duplicated time and effort spent by experts around the world when designing new versions of the EAMBs. Therefore, it is suggested to apply an approach to determine these variables’ effect on the estimated weights of the assessment items for the different assessment methods, noting that due to the presence of other private and local variables, the final estimated weights of the items may vary from one method to another, and from one building type to another. Thus, the research aims to spot a light on the possibility and ability of unifying the importance degree and effect of the global common variables on estimating the weights of the assessment items among the EAMBs, which will not lead to unified items’ weights, but it ensures their importance degree over the world due to their worldwide concern, and reduces the duplicated effort and time waste of the experts responsible for producing the different environmental methods.
Abstract: Publication date: April 2018Source: HBRC Journal, Volume 14, Issue 1Author(s): Mohamed Moawad, Anwar Mahmoud, Hossam El-karmoty, Ashraf El zanaty Prestressed concrete is widely used in the construction industry in buildings. And corrosion of reinforcing steel is one of the most important and prevalent mechanisms of deterioration for concrete structures. Consequently the capacity of post-tension elements decreased after exposure to corrosion. This study presents results of the experimental investigation of the performance and the behavior of partially prestressed beams, with 40 and 80 MPa compressive strength exposed to corrosion. The experimental program of this study consisted of six partially prestressed beams with overall dimensions equal to 150 × 400 × 4500 mm. The variables were considered in terms of concrete compressive strength, and corrosion location effect. The mode of failure, and strain of steel reinforcement, cracking, yield, ultimate load and the corresponding deflection of each beam, and crack width and distribution were recorded. The results showed that the partially prestressed beam with 80 MPa compressive strength has higher resistance to corrosion exposure than that of partially prestressed concrete beam with 40 MPa compressive strength. Not big difference in deterioration against fully/partially corrosion exposure found between partially prestressed beams at the same compressive strength. The most of deterioration incident in partially prestressed beam acts on non prestressed steel reinforcement. Because the bonded tendons are less likely to corrode, cement grout and duct act as a barrier to moisture and chloride penetration, especially plastic duct without splices and connections. The theoretical analysis based on strain compatibility and force equilibrium gave a good prediction of the deformational behavior for high/normal partially prestressed beams.
Abstract: Publication date: Available online 24 March 2018Source: HBRC JournalAuthor(s): Dina A. Emarah, Safwat A. Seleem A numerical parametric study using the finite element program of PLAXIS was performed on single and double anchored sheet piles systems using different types of sandy soil backfill (loose, medium dense, and dense sand). This numerical study aimed at evaluation of the variation of maximum values of bending moments and anchor forces exerted in the sheet piles. This evaluation was affected by varying of some parameters such as the embedded depth, positions of anchor rods either the upper rod or the lower one, and the sheet pile wall flexural rigidity. For all cases, a surcharge strip load of different values covering a width of about 0.5 of the free height (h) was placed at a free distance of 0.20 h away from the wall of sheet pile. Furthermore, the effect of earth pressure due to both the own weight of backfill soil and the surcharge were considered. The study results indicated that the forces developed in the lower anchor rods are always higher than those developed in the upper anchor rods. The higher value of maximum bending moment achieved at the stiffer sheet pile wall. Finally, in the double anchored sheet pile wall, the lower values of anchor forces and that of maximum bending moments were achieved at the higher density of the soil.
Abstract: Publication date: Available online 21 February 2018Source: HBRC JournalAuthor(s): Mohamed F. Mansour, Muhammad D. Saad El-Din, Yasser M. El-Mossallamy, Hesham A. Mahdi Geotechnical design is carried out according to one of two main methods; the Working Stress Design (WSD) and the Limit States Design (LSD) methods. The LSD can be carried out according to two main approaches; the Factored Strength Approach (FSA), and the Factored Resistance Approach (FRA). The use of LSD in Egypt is limited to the design of reinforced concrete structures. The geotechnical design is still based on the WSD method. The updated Egyptian Geotechnical Code will include both methods for a transition period before fully adopting the LSD. This study describes the methodology and results of determination of the partial factors for the limit states FSA for cantilever walls in dry cohesionless soils such that the LSD matches the WSD. These calibrated values are essential for the transition period when both the WSD and LSD design philosophies are applicable. The study recommends a partial factor of 1.25 in the future version of the Egyptian Code for the limit states FSA design of cantilever walls in dry cohesionless soils, which agrees with the current state of practice in different international codes.
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