The behavior of reinforced concrete beams containing fibers made of waste plastic straws (WPSs) under the three point bending test is examined. The eect of WPS fiber addition on the compressive and split tensile strength is reported. Four concrete mixes were prepared. The control mix PS-0 had a proportion of 1 cement: 1 sand: 2 coarse aggregate and a water cement ratio of 0.4. In the other three mixes PS-0.5, PS-1.5 and PS-3, 0%, 0.5%, 1.5% and 3% of WPS fiber (by volume) was added respectively. The results show that at 0.5% WPS, there is slight increase in compressive strength. However, beyond 0.5% addition, a decrease in compressive strength is observed. The split tensile strength shows a systematic increase with the addition of WPS fibers. The reinforced concrete beams containing WPS fibers show higher ductility as demonstrated by the larger ultimate tensile strain and ductility index (Du/Dy). There is a tendency to have more fine cracks with the presence of WPS fibers. arabic 9 English 76
Hakim S. Abdelgader(10-2020)

Abstract this study aims to investigate the hydrological cycle at wadi Zaghadnah basin in Tarhuna in terms of (rainfall-surface run-off-evaporation-infiltration) and estimation of the quantity of surface water , and to predict the maximum flood can happen in order to reduce hazardous to houses and farms that are found on my profile of the valley was the use of a series of years of readings rainfall and results have indicated to the fact that annual average rainfall was (238) mm, via using (Isohyetal method).The quantity of water which is supposed to be reserved in the dam was (1.94) million cubic meters. As for rain test, it was found that it is random and non-coherent. Having studied rain-wave relation through application of modelprediction statistical, it was deduced that it is not reliable to depend-upon in forecasting the expected rain. Results have indicated that total evaporation average to (2324.5)mm via using (CROPWAT) and average annual infiltration is (2065.17)mm, and post application of some statistic equations like probability log-Pearson Type ׀׀׀distribution and Gumbels distribution-plotting (25-50-100-1000), maximum possible amount (via using the aforesaid three methods) was found, but due to silt and likely erosion of soils as a result of flooding, silt amounts in Dom lake was estimated by using calculative equations was (5622)m³/year.
عيادة محمد ميلاد اليونسى (2012)

Two-stage concrete (TSC) is characterized by its exceptional placement technique, whereby aggregates are first pre-placed in the formwork then injected with a flowable grout. The quality of TSC grout is a controlling factor of the mechanical strength and durability of TSC. Therefore, this study investigates the properties of grout mixtures incorporating two types of fine aggregate including natural sea sand and crushed fine aggregate. The grout mixtures proportions were prepared at a water-to-cement ratio (w/c) of 0.45. Three fine aggregate-to-cement ratios (fa/c) of 0.5, 1.0 and 1.5 were tested. Results indicate that grout mixtures made with natural sand exhibited higher flowability and lower bleeding resistance than those made with crushed fine aggregate. Moreover, increasing the fine aggregate content reduced the grout flowability, while it improved the bleeding resistance and compressive strength. It was concluded that grout mixture made with crushed fine aggregate, (fa/c) = 1.0, and 0.8% high-range water-reducing admixture (HRWRA) was the best for successful TSC grout since it exhibited acceptable flowability, excellent bleeding resistance and high compressive strength. arabic 14 English 79
ENAS AB MOHAMED ELMUSRATI, , , (1-2021)