This experimental study investigates the influence of replacing certain ratios of natural aggregate by recycled concrete aggregate on properties of fresh and hardened concrete. Two maximum nominal sizes of aggregate used in this study 40 mm and 20 mm, the source of used recycled concrete aggregate comes from the demolitions of the upper skeleton of Al-AZHAR building in Sohag. Thirty six mixes were designed and carried out to study the effect of both aggregate size and replacement ratios on concrete properties, the replacement ratio of recycled aggregate changed from 0 to 50% using of two sizes of aggregate 20 and 40 mm. A slump and compacting factor were measured to express fresh concrete properties, hardened concrete properties were expressed by compressive strength tests after 7 and 28 days, pull out bond strength, splitting tensile strength and flexure strength. Test results shows the bad effect of replacing natural aggregate by recycled concrete aggregate on both fresh and hardened concrete properties.

The cable stayed bridges represent key points in transport networks and their seis mic behaviour need to be fully understood. This type of bridge, however is light and flexiable and has a low level of inherent damping. Consequenly, thery are susceptible to ambient excitation from seis mic loads. Since the geometric and dynamic properities of the bridges as well as the characteristics of the excitations are complex, it is necessary to fully understand the mechanism of the interaction among the structural componenets with reasonable bridge shapes. This paper discuss the dynamic response of a cable stayed bridge under seismic loadings. All possible sources of nonlinearity, such cable sag, axial-force-bending moment interaction in bridge towers and girders and change of geometery of the whole bridge due to large displacement are based on the utilization of the tangent stiffness matrix of the bridge at the dead-load deformed state which is obtained from the geometry of the bridge under gravity load conditions ,iterative procedure is utilized to capture the non-linear seismic response and different step by step integration schemes are used for the integration of motion equations. In this study, three spans cable-stayed bridge with different cable systems has been analyzed by three dimensional nonlinearity finite element method. The three dimensional bridge model is prepared on SAP 2000 ver.14 software and time history analyses were performed to assess the conditions of the bridge structure under a postulated design earthquake of 0.5g. The results are demonstrated to fully understand the mechanism of the deck-stay interaction with the appropriate shapes of a cable stayed bridges.

In many times, a good distribution and implementation of equipment and machines along the quarry faces is considered a challenge to the mining engineer or the quarry operator. Quarry equipment includes drilling machines, air compressors, loading equipment including loaders and/or excavators, in addition to the transportation fleet of high-tonnage trucks. These equipment cost large investments in the production processes and need high skill to be efficiently distributed and operated. In this investigation, study of the optimum distribution of the available drilling machines of different specifications and capacities along the faces of the lime stone quarry of Assiut Cement Company has been carried out. A mathematical model has been used to find several alternatives and to choose the best alternative. Calculation of the minimum number of drilling machines that satisfy the annual production plan is an important step to decrease production costs.

In many times, a good distribution and implementation of equipment and machines along the quarry faces is considered a challenge to the mining engineer or the quarry operator. Quarry equipment includes drilling machines, air compressors, loading equipment including loaders and/or excavators, in addition to the transportation fleet of high-tonnage trucks. These equipment cost large investments in the production processes and need high skill to be efficiently distributed and operated. In this investigation, study of the optimum distribution of the available drilling machines of different specifications and capacities along the faces of the lime stone quarry of Assiut Cement Company has been carried out. A mathematical model has been used to find several alternatives and to choose the best alternative. Calculation of the minimum number of drilling machines that satisfy the annual production plan is an important step to decrease production costs.

In many times, a good distribution and implementation of equipment and machines along the quarry faces is considered a challenge to the mining engineer or the quarry operator. Quarry equipment includes drilling machines, air compressors, loading equipment including loaders and/or excavators, in addition to the transportation fleet of high-tonnage trucks. These equipment cost large investments in the production processes and need high skill to be efficiently distributed and operated. In this investigation, study of the optimum distribution of the available drilling machines of different specifications and capacities along the faces of the lime stone quarry of Assiut Cement Company has been carried out. A mathematical model has been used to find several alternatives and to choose the best alternative. Calculation of the minimum number of drilling machines that satisfy the annual production plan is an important step to decrease production costs.

In many times, a good distribution and implementation of equipment and machines along the quarry faces is considered a challenge to the mining engineer or the quarry operator. Quarry equipment includes drilling machines, air compressors, loading equipment including loaders and/or excavators, in addition to the transportation fleet of high-tonnage trucks. These equipment cost large investments in the production processes and need high skill to be efficiently distributed and operated. In this investigation, study of the optimum distribution of the available drilling machines of different specifications and capacities along the faces of the lime stone quarry of Assiut Cement Company has been carried out. A mathematical model has been used to find several alternatives and to choose the best alternative. Calculation of the minimum number of drilling machines that satisfy the annual production plan is an important step to decrease production costs.

Rubber is used in many industrial applications, specially those need high damping capability. In present work, the effects of cyclic loading conditions on fatigue lifetime of the styrene butadiene (SBR) and nitrile-butadiene rubber (NBR) with 0,20,30,50 and 70 Phr of carbon black contents were investigated. Two cyclic loading conditions, namely full relaxation and non-relaxation tension, were considered. It was found that, in full relaxation tension test, i.e. R=0, fatigue lifetime increased with the decrease of the maximum strain. The decrease of maximum strain was accompanied with decrease in the maximum stress and stress amplitude. It was also found that, in non-relaxation tension test i.e. R>0, fatigue lifetime increased with the increase of the minimum strain, as well as, with the decrease of the stress amplitude. In this case, fatigue lifetime increased in spite of the fact that the increase of the minimum strain was accompanied with increase in the maximum stress at constant maximum strain. Consequently, it was found that the increase of minimum strain was beneficial in increasing the lifetime. It was also found that fatigue lifetime of rubber could be improved by increasing the carbon black content at the test conditions used in experiments.

This paper studies the apparent ground resistivity in two-horizontal layer ground and in two-vertical layer ground through the site measurements obtained. Wenner method was used to measure apparent ground resistance in different grounds. A numerical model was proposed to model the four electrode buried in ground. The apparent ground resistivity had been studied for different conditions which are two-horizontal and -vertical layer grounds. Field measurements had been done in various sites close to water channel and also far away from any apparent vertical layer ground. Generally, the calculated results agreed with the measured results. Analytical calculations had been proposed to distinguish between two-horizontal and two-vertical layer ground.

Fayoumi Standard Weirs have been modified by adding one, two or three pipes, to convey much water to downstream direction. Measurements of discharge with these structures are complicated due to existence of the openings. In this research, an experimental study is carried out to investigate the effect of installing pipes through a piped clear over fall weir and bottom-pipes. Twelve weir models with different heights are tested in horizontal laboratory flume of 17 m length, 0.3 m width, and 0.5 m depth. Weir height is changed two times. Contraction of weirs is changed two times. For each one, the diameter of opening is changed three times. The downstream depth is changed to cover all the concerned flow regimes of flow rate for a submerged pipe and a free weir. The downstream water depth begins with the upper tangent of the pipe and ends with the crest level of the weir. The contraction and the un-contraction of the weir are discussed. The effect of downstream water depth is taken into consideration. The results of flow over weir with opening are compared with those of weir without opening having the same dimensions. It is found that there is a large difference between them. Multiple regression equations based on energy principal and dimensional analysis theory are developed for computing discharge over clear over fall weir with bottom pipes. Also, values of discharge coefficients were estimated for combined flow over the weir and through the pipe. Then the total discharge can be computed by multiplying the discharge coefficient by the summation of theoretical weir discharge plus theoretical orifice discharge. Equations for computing the discharge of combination are awarded

The aim of this work is to improve the fresh and hardened concrete properties made from recycled concrete aggregate, by using a non-traditional admixture.As the previous researches concluded, using different ratios of recycled concrete aggregate has a harmful effect on the properties of fresh and hardened concrete. Otherwise, itpresents a cheap, environmental and sustainable concrete by using the waste materials of demolitions to replace the natural aggregate in concrete mixes. Therefore, organic non-traditional admixture is used in this study to improve fresh and hardened concrete properties.The admixture was prepared using a cheap local material mainly from wastes of vegetable oil industries.Six different types of admixtures were prepared to select the best and most homogenous one.The suggested admixture gives best workability and increase thecompressive strengthof concrete mixescontaining recycled concrete aggregate.