ايام جبار جهاد الاسدي

This research aim to study the effect of super plasticizer CF-555 on compressive , tensile and flexural strength and modulus of elasticity of ordinary concrete , the study show that using 1.2 liter gives the optimum mechanical properties , compressive strength increased from 31.2 MPa to 44.7 MPa , flexural strength increased from 2.5 MPa to 6.4 MPa , and modulus of elasticity increased from 22060 MPa to 29532 , the high dosages of super plasticizer lead to decrease the mechanical properties of concrete , because of action of fluidity that leads to segregation and that lead to decrease in mechanical properties.

Abstract : The use of waste aggregate in concrete is very important because that decrease the total cost of concrete and lead to more clean environment . This research aims to study the mechanical properties such as compressive , tensile and flexural strength and also he modulus of elasticity for concrete containing waste glass as coarse and fine aggregate and improved also with integral waterproofing admixture . The study shows the improvement in mechanical properties due to using waste glass only and waste glass with integral waterproofing admixture , compressive strength increased from 27.3 to 35.8 MPa by total glass replacement , but using both glass and waterproof lead to rise compressive strength to 54.38 MPa , also other mechanical properties increased highly by using glass and waterproofing admixture .

this research aims to study the effects of high performance superplasticizer or hyper superplasticizer on mechanical properties of concrete include compressive , tensile and flexural strength. Superplasticizers in general are a water reducer admixtures that give concrete high workability and higher strength , but the use of superplasticizers must done with care ,because higher dosages ratio lead to segregation and lower ratios not have significant effects ,so for these reasons this research include the use of different dosages of HP and studying the ratios effect on mechanical properties and taking the optimum ratio of HP that use with steel fibers mixes .study show 1liter for each 100 kg cement leads to give optimum mechanical properties of concrete . Steel fibers increase slightly compressive strength but flexural strength is highly increased by adding fibers , mixes with both HP super plasticizer and steel fibers give best results . compressive strength increased from 34.6MPa for reference mixes to 49.90 MPa for mixes with 2% steel fibers and HP with 1 liter for each 100 kg cement . flexural strength increase also from 2.3 to 13.28 MPa by using both steel fiber and HP-superplasticizer.

Numerical modeling of sediment transport is the best tool to simulate sediment transport in a water body. The present paper uses numerical computational fluid dynamics “CFD” computer program Sediment Simulation In Intakes with Multiblock option "SSIIM" which considers flow and sediment equations in a three dimensional manner to predict the flow field and sediment transported upstream of Al-Ghammas Barrage, middle of Iraq on Euphrates river. It solves the Reynolds-averaged Navier-Stokes equations in three dimensions to compute water flow using the finite volume approach as discretization method, and also the convection-diffusion equation for sediment transport. The model was based on a three dimensional, non-orthogonal, structured grid with a non-staggered variable placement. The comparison between filed measurements and numerical results were considered to make the correct decision in this model. The verification showed good agreement between model results and observed data for suspended sediment concentration, depending on the value of coefficient of determination (0.94).