Latest Issue: Volume 67,
Skylights are widelyutilized in buildings to improve daylighting conditions for deep spaces. However, the majority of skylightsin historical spacesare not efficiently designed to adapt to public reuse and they uncover challenges insatisfying daylight requirementsof potential visitors. This paper investigatesa case of an old historical palace located in Cairo, Egypt, originally designed as a residence. The reuse purpose is a public museum where daylight plays an important experiential dimension,which makes it more challenging to adjust to the new daylighting conditions. In this study, adequacy of daylight is tested and verified witha developed comprehensive simulation modelbased on Daysim, for investigating the daily illuminance levels for fixed points on a 5×5 m grid. Comparative analysis is performed between simulation results and actual palace lux readings taken on the same created grid for the different skylight affectedfloor levels. Finally, the most significant skylight influential factors on the daylight performance are discussed for further skylight redesign with optimum performance.
The treatment with double-skin facades has recently been observed, and there is a conflict of opinion when choosing the depth of the air cavity between the two layers of skin of the facades, which ranges from 0.20 m: 2.00 m, resulting in interfaces that do not meet the needs of the users (thermal comfort, natural light,and air flow). The paper aimsto determinethe best suitable air cavity depth for buildings in hot areas, by following the experimental inductive method and analytical descriptive method.Process simulationon a scaled model in the laboratoryis performed to determine the appropriate depth of the cavity that reducesair temperature of the internal spaces, and the proper air speed that achieves thermal comfort.It isconcluded that there is an inverse relationship between the air speed and the depth of the air cavity.
The paper aims to develop the assessment strategies in the construction industry in an attempt to achieve end-project goals. No methods are available for an assessment strategy for the contractors based on evident aspects. The Key Performance Indicators (KPIs) draw guidelines and give a roadmap for the decision makers. It helps to select the most appropriate contractor to implement the proposed projects. The Egyptian Federation for Construction and Building Constructions did not provide an assessment plan for the technical experiences through scientific indicators. This paper therefore attempts to provide the core KPIs in the construction field. All KPIs are presented with the different selection methods. These will then be rated and the core KPIs will be selected according to scientific theories. The main objective of the study is to develop a new strategy for contractor assessment via core KPIs in the tendering stage. The study uses a scientific path starting with theoretical and analytical studies, followed by a pilot case study to verify the validity in the practical field. The conclusions highlight the different levels affected by the core KPIs.
Flyovers and bridges are vital infrastructure elements in the built environment. They are built to solve traffic and mobility problems especially in cities with high traffic density. Usually, those flyovers do notconsider the architecture and city urban aesthetics. At the end of the 20thcentury, numerous national authorities and agencies initiated a new term "context-sensitive design", promoting the importance of bridge aesthetics. The research focuseson the flyover negative effects on urban aesthetics, with special reference to heritage urban spaces in Cairo, Egypt.Theaim is to draw attention to the importance of issuing guidelines concerned with flyover aesthetic values for urban areas. This is achievedthrough documenting and analyzing international pilot bridge and flyover aesthetics guidelines. The paper also documents and analyzes the situation in Cairo, Egypt through visual inspection and interviews. El-Azhar area and El-Azhar flyover, Cairo, Egypt are chosen as thearea for field study. The paperpresents a list of flyover-negativeinterventions on the built environment and community together with a proposalto includethe main elements in future guidelines.
This paper aims to analyze and compare the effect of using grass, or trees with grass as a bioclimatic landscape design strategy. The study is simulation-based, where ENVI-met was used to model and simulate different scenarios. The start-up scenario represented the existing buildings of the selected entertainment venue.Aset of scenarios representing 40% and 60% of either grass or trees with grasswere then established. Simulations were run on a typical summer day. The Predicted Mean Vote (PMV) for all thescenarios was calculated using BIOMET, also outdoor air temperature was compared. The results of the simulations pointed out that increasing the percentage of different treatments helped in enhancing thermal comfort level with significanteffects. However, scenarios using different percentages of grass coverage with trees always resulted in the highest effect. In the case of adding trees to grass surfaces, the simulated PMV results ranged between 3.16 and 1.73. For grass with trees coverage scenarios, the simulated air temperature values ranged between 27.6°C and 34.38°C. The increase in grass coverage and adding treescausedchange between 1°C dropsat 10:00 and 0.36°C at 14:00.The results showed that adding grass and trees result in significant drop in outdoor thermal comfort and air temperature.
Ezbet El-Haggana, in Cairo, is an informal settlement on a desert state-owned land. It is currently surrounded by formal lands, making expansion impossible. Maps of Ezbet El-Haggana of 2006 and 2017 show an enormous urban transformation within the informal land. The purpose of this paper is to document and analyze the residential typologies to trace the urban physical transformation in Ezbet El-Haggana. The study relies on informal discussions, resident-led walks, onsite sketches, observation, photographs, and urban mapping. The analysis of the residential typologies clarifies the reasons behind the dramatic change in the urban fabric. This change emerged through a real-estate investment act, which replaces small one family residences with apartment buildings that accommodate more than forty families each. This act caused two changes in the informal settlement: transformation in the urban fabric from fine-grained to coarse-grained, and increase in the number of families per residential typology. Furthermore, mapping the location and dominance of those residential typologies was conducted, highlighting different urban physical transformation patterns within Ezbet El-Haggana. The urban areas, with proximity to the highway and formal neighboring lands, have witnessed a massive physical transformation. However, the heart is currently experiencing a rapid change in the urban fabric.
The research problem lies in reaching sustainability of buildings through nanotechnology and its applications in architecture. Sustainable urban and architectural environment should adopt alternative technologies rather than traditional ones in an attempt to find smart, renewable and recyclable building materials. These would then be adapted to serve human beings and the environment. The research is based on the inductive inference approach and includes the identification of nanotechnology and its impact on the environment, sustainable architecture. The analytical approach, which is the study of Nano applications in construction through the analysis of some examples of existing projects and then reaching the results and recommendations. In light of the world's suffering from the spread of epidemics and current natural conditions, it is recommended to use nanotechnology to improve the performance of building materials and coatings to raise the efficiency of buildings using these environmentally friendly materials in order to reach a sustainable building that serves humanity and the environment.
One of the most important phases while planning any new residential urban community is to determine the floor area constraints suitable for the type and scale of the project in addition to determining the area standards and ratios for the open, recreational, and vehicle spaces. The study proposes a computerized tool using visual basic for applications (VBA), provided within the Microsoft Excel software, to extract the numerical standards for residential complex projects urban design area factors. The study uses the best fit functions using regression analysis to simulate the graphical logarithmic relationships consisted in the land-use intensity (LUI) comprehensive determining system, which is a compulsory system imposed in the Egyptian code for housing design and residential complex. The study aims to solve the difficulties mentioned by the experts for the application of the LUI system in addition to decreasing the time and the effort of calculations by converting the manual procedures into systematic equations that can be converted into a software script.
The purpose of this paper is to compute time period for tall buildings rested on piled-rafts including soil-structure interaction effects. The pile-pile, pile-soil and soil-soil interactions are considered through the development of two-iteration based coupling procedures between the super and sub-structures. The super-structure is modeled using any commercial finite element software, whereas the sub-structure including the building foundation is modeled using a developed boundary element software (PLPAK). It was demonstrated that the consideration of soil-structure interaction greatly increases the time period and consequently reduces the seismic design forces.
The time period of structures has a significant effect on seismic forces calculations. However, most of the design code use an approximate empirical formula that depends mainly on building height, for time period estimation. The aim of this study is to investigate the effect of lateral load resisting systems and irregularities of building configuration on the fundamental period of vibration for steel structures. For this purpose, steel buildings with different lateral systems and irregularities were selected. 36-Moment Resisting Frames (MRFs), 108-Concentric Braced Frames (CBFs) and 68-Eccentric Braced Frames (EBFs) were studied using ETABS software. Three heights were considered; 5, 8, and 12 story and three types of irregularity were investigated; vertical, horizontal and combined irregularities. After full analysis and optimum design for buildings, the results of the fundamental periods of vibration of this study were compared with the time period recommended by different international design codes and standards. The comparison showed that the lateral system and building irregularity have a significant effect on the fundamental period of vibration for the buildings with the same height. It is recommended that the code equation for irregular steel buildings be investigated further.
In this research, the performance of slag with metakaolin based geopolymer concrete in aggressive media is investigated. Firstly, the effect of adding metakaolin on the compressive strength of slag based geopolymer mortar is studied. Ordinary Portland cement and geopolymer concrete samples are then prepared and cured in water for 28 days then immersed in tap water and in an aggressive media for 90 days. The durability of samples is assessed using compression test, Fourier Transform Infrared Spectroscopy and Scanning Electron Microscopy. Also, Linear Polarization Resistance technique is utilized to assess the corrosion rate of steel embedded in concrete samples. It is concluded that replacing slag by 5% metakaolin by weight leads to the highest compressive strength. The compressive strength of geopolymer in aggressive media boosts by up to 30% compared to tap water. Also, the corrosion rate of steel in geopolymer samples nearly diminishes in different media. Moreover, the microstructure of geopolymer matrix shows more stable behavior in aggressive media compared to Portland cement.
Ultimate bearing capacity of shallow foundations under axial vertical loads resting on strong cohesionless soil overlying weak deposit was investigated. Previous studies addressed simplified failure mechanisms and punching shear failure mechanism. In this paper, stress analysis using the limit equilibrium method was performed on an assumed failure plane, which is believed to be close to the observed failure plane from experimental investigation available in the literature. Furthermore, the footing will fail by punching of the upper layer through to the lower by a truncated column making an angle alpha with the vertical. The results showed that the ultimate bearing capacity of a footing on a strong sand layer overlying weak sand deposit depends on the relative shear strength of the two layers, footing geometry, embedment depth, and the thickness of the upper sand layer. The theoretical model developed was validated with the available experimental data in the literature, where good agreement was noted.
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