This study aims to investigate experimentally the behavior of self-compacting reinforced concrete dapped end beams strengthened with CFRP sheets and, then theoretically by ANSYS 15.0 software. The experimental program consists of testing 14-specimens each of dimensions (200x400x1500 mm) with two values of Shear span to depth effective (a/d), namely (1.5 and 1.0). Two of the beams are a control beams (with full reinforcement), and four beams with reduced reinforcement in hanger and nib regions. The other beams have been strengthened with several configurations by CFRP sheets for the same values of (a/d), the comparison between results included load-deflection curves and cracked specimens. It was found that the strut and tie model (STM) is very conservative somehow, reduction the nib reinforcements by about (60%), in reduction in failure load by about (35% and 15%) for the two values of (a/d). With respect to the strengthened specimens, it observed that the strengthening with inclined CFRP strips (450) yielded better results in comparison with other configurations. The improvement in load capacity was about (23%) for (a/d=1.5 and 1.0). Also, it is found that the nonlinear model adopted in the present work compered the experimental tests yielded a good agreement with difference of about (12%).

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This study has focused on investigation of effect of hydrostatic pressure on the properties of underwater self-compacting concrete. In this research, 30 mixes of self-compacting concrete have been prepared with six groups. The first three groups contain AWA (Anti Washot Admixture), while the second groups made without AWA. The main parameters explored in this research were: silica fume, limestone powder and rice husk ash as a cement replacement content with 0% and 1% anti washout admixture and different water depth (10 ,20, 30 ,40 and 50 m). Washout loss was found by using either the CRD C61 test method or a newly developed device for simulation of increased hydrostatic pressure on the concrete/water interface. Good correlations were investigating between the standard washout loss determined according to CRD C61 and simulated threshold water head and corresponding maximum washout loss.

No-fines concrete is a form of lightweight concrete obtained when fine aggregate is omitted. No-fine concrete mainly used for both load bearing and non-load bearing for external walls and partitions and in in-filling panels in framed structures. The essential objective of this work is to investigate the effect of incorporation of polymer (SBR) on the performance of no-fine concrete made from lightweight aggregate (porcelinite) and to suggest possible applications of this type of concrete. Three concrete mixes with different aggregate/cement ratios (A/C) (6:1, 8:1 and 10:1) by volume were selected. Each of these mixes included six mixes which differed in polymer/cement ratios, (0%, 5%, 10%, 15% and 20%) by weight to find the optimum polymer/cement ratio. Density, compressive strength, splitting tensile strength and drying shrinkage were conducted on all concrete mixes. The test results showed that the compressive strength of no-fine lightweight aggregate concrete increased with the increase in polymer/cement ratio up to 15%, and the compressive strength reduced at polymer /cement ratio of 20% . At polymer/cement ratio of 15%, the percentage of increase in compressive strength measured relative to reference mixes was about 50%. On the other hand, the splitting tensile strength was increased with the increase in polymer/cement ratio for all mixes. The percentage of increase in splitting tensile strength compared with reference mixes increased fr0m about 30 to 90% with the increase of polymer/cement ratio fr0m 5 to 20 %. Also the drying shrinkage strains of no-fine concrete decrease, with the increase in polymer/cement ratio. The percentages of decrease in drying shrinkage strain at 56 days were fr0m 5 to 30% with the increase of polymer/cement ratio fr0m 5 to 20%.