External confinement of concrete columns by means of carbon fiber reinforced polymer (CFRP) sheets can be considered as an efficient technique for their structural strengthening. An experimental research program including 18 circular short column specimens were tested under axial compression load, to investigate the gain strength of reinforced concrete (RC) columns confined with CFRP sheets. The parameters studied were both the volume and configurations of CFRP sheets, the size of cross-section, the percentage of main reinforcement, and the volume of internal stirrups. On the basis of the obtained results, mathematical models (Egyptian code and American Concrete Institute code) proposed to predict the axial compressive strength of non-slender RC column strengthened by means of CFRP sheets are evaluated. These codes showed an underestimation in predicting the axial compressive strength of RC strengthened columns. This, from the authors’ point of view, is attributed mainly to the fact that the proposed models overlooked the amount of internal stirrups when calculating the strength of strengthened columns. Therefore, modifications in the studied models were considered. The modifications take the effective lateral confining pressure due to presence of internal steel stirrups into account. The modified codes showed an acceptable approach to the experimental results

Recent experimental results of the FRP–concrete bonded joint using flexible adhesive showed that the most popular analytical models available in the literature underestimate the bond strength and the effective bond length of these experiments. Most of these existing models need to be modified to consider the type of adhesive layer. Consequently, the bond strength model proposed by Chen and Teng (2001) has been modified to consider the type of adhesive layer. An extensive database consisting of about 100 test results of FRP–concrete joint has been assembled to examine the validity of the proposed model taking the type of adhesive layer into consideration. The modified bond strength model is accurately capable of predicting the bond strength and the effective bond length.

Recent experimental results of the FRP–concrete bonded joint using flexible adhesive showed that the most popular analytical models available in the literature underestimate the bond strength and the effective bond length of these experiments. Most of these existing models need to be modified to consider the type of adhesive layer. Consequently, the bond strength model proposed by Chen and Teng (2001) has been modified to consider the type of adhesive layer. An extensive database consisting of about 100 test results of FRP–concrete joint has been assembled to examine the validity of the proposed model taking the type of adhesive layer into consideration. The modified bond strength model is accurately capable of predicting the bond strength and the effective bond length.

Houses in Egypt are often designed without taking the climate into account sufficiently. Consequently, new houses often have a poor indoor climate, which affects comfort, health and building efficiency. In hot and arid climates, passive cooling system employs non-mechanical procedures to maintain suitable indoor temperature. Thus, they have been increasing the influence of the traditional cooling concepts but with new technology. Therefore, these conditions encourage such a concept to enhance natural ventilation with evaporative cooling and save energy in the New Assiut city. In the present study, the effect of solar chimney parameters on wind tower parameters was numerically investigated as a second phase of the new integrated model. All the detailed mathematical equations and system description are presented in phase one. A numerical simulation is implemented in Transient systems simulation program-Conjunction of multizone infiltration specialists program softwares. The parametric studies of the integrated system in phase two were studied to achieve high performance with new compact small design especially for the hottest days in the summer season. The temperature and airflow rates are predicted iteratively taking into account the zone pressure and the pressure drop in the evaporative cooler component. The result shows that the system achieves nearly at least close to 80 % acceptable comfort range according to Adaptive Comfort Standard of American Society of Heating, Refrigerating and Air-Conditioning Engineers with optimum ventilation rate 414 m3/h for the hottest day. The findings show that the system achieves high performance in the hottest day with small solar chimney dimension and is easy to integrate in the building envelope than the proposed system before parametric studies in phase one.

Houses in Egypt are often designed without taking the climate into account sufficiently. Consequently, new houses often have a poor indoor climate, which affects comfort, health and building efficiency. In hot and arid climates, passive cooling system employs non-mechanical procedures to maintain suitable indoor temperature. Thus, they have been increasing the influence of the traditional cooling concepts but with new technology. Therefore, these conditions encourage such a concept to enhance natural ventilation with evaporative cooling and save energy in the New Assiut city. In the present study, the effect of solar chimney parameters on wind tower parameters was numerically investigated as a second phase of the new integrated model. All the detailed mathematical equations and system description are presented in phase one. A numerical simulation is implemented in Transient systems simulation program-Conjunction of multizone infiltration specialists program softwares. The parametric studies of the integrated system in phase two were studied to achieve high performance with new compact small design especially for the hottest days in the summer season. The temperature and airflow rates are predicted iteratively taking into account the zone pressure and the pressure drop in the evaporative cooler component. The result shows that the system achieves nearly at least close to 80 % acceptable comfort range according to Adaptive Comfort Standard of American Society of Heating, Refrigerating and Air-Conditioning Engineers with optimum ventilation rate 414 m3/h for the hottest day. The findings show that the system achieves high performance in the hottest day with small solar chimney dimension and is easy to integrate in the building envelope than the proposed system before parametric studies in phase one.

Houses in Egypt are often designed without taking the climate into account sufficiently. Consequently, new houses often have a poor indoor climate, which affects comfort, health and building efficiency. In hot and arid climates, passive cooling system employs non-mechanical procedures to maintain suitable indoor temperature. Thus, they have been increasing the influence of the traditional cooling concepts but with new technology. Therefore, these conditions encourage such a concept to enhance natural ventilation with evaporative cooling and save energy in the New Assiut city. In the present study, the effect of solar chimney parameters on wind tower parameters was numerically investigated as a second phase of the new integrated model. All the detailed mathematical equations and system description are presented in phase one. A numerical simulation is implemented in Transient systems simulation program-Conjunction of multizone infiltration specialists program softwares. The parametric studies of the integrated system in phase two were studied to achieve high performance with new compact small design especially for the hottest days in the summer season. The temperature and airflow rates are predicted iteratively taking into account the zone pressure and the pressure drop in the evaporative cooler component. The result shows that the system achieves nearly at least close to 80 % acceptable comfort range according to Adaptive Comfort Standard of American Society of Heating, Refrigerating and Air-Conditioning Engineers with optimum ventilation rate 414 m3/h for the hottest day. The findings show that the system achieves high performance in the hottest day with small solar chimney dimension and is easy to integrate in the building envelope than the proposed system before parametric studies in phase one.

This study concerns road traffic noise in Alexandria, the second biggest city in Egypt. Goals of this study are to carry out measurements to evaluate road traffic noise levels, are these levels exceeded permissible noise levels set by Egyptian noise standard and policy to protect public health. To carry out restrictions to reduce noise levels for improving environmental conditions. Measurements taken for traffic noise levels, indicates that noise levels are higher than those set by Egyptian noise standards. Ldn = 80 dB and higher were recorded, while maximum permissible level is 60 dB. Ldn are calculated for 22 locations spread over different urban zones of city. It was found out that 95.5 % out of locations display Ldn are over 65 dB. 86.4 % out of total number of locations their Ldn are over 70 dB. Results of restrictions found that (i) in absence of horns, Ldn decreased at all sites reduction was 11.2 dB occurred in downtown area. (ii) In absence of horns, trucks and buses reductions in Ldn range between 6.2 to 14.3 dB. This shows that town planner can use various strategies to change traffic composition in order to achieve quieter city environments.

Fatigue behaviour of rubber is a very important characteristic due to its extensive use in many engineering applications. In most applications, rubber is commonly subjected to fluctuating loads, which often lead to failure due to the nucleation and growth of defects or cracks. Due to their viscoelastic behavior, rubbers have a high damping ability. Very often rubbers are subjected to different frequencies in the service, such as engine mounts. The effect of frequency on the fatigue lifetime needs deep investigations. In present work, the effect of frequency on the styrene butadiene (SBR) and nitrile-butadiene rubber (NBR) with 0,20,30,50 and 70 Phr of carbon black was investigated. It was found that the fatigue lifetime decreased with the increase of the frequency. Increasing carbon black (CB) contents in rubber improved the fatigue resistant and increased of the fatigue lifetime.

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Milling is a machining process by which a surface is generated by a progressive chip removal. An experimental investigation has been carried out on the performance of up and down milling under dry and flood conditions when end milling medium carbon steel utilizing titanium coated carbide tools. The performances are evaluated in terms of the cutting force, specific energy and power of cutting tool. The results show that milling in dry condition under up milling mode produce higher cutting force, specific energy and power. However, cutting under down milling mode gives less significant effect either being cut in dry or flood condition.