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Experimental investigation is carried out to study the shear transfer of uncracked fibrous concrete. The test specimens used in this study were of the push-off and modified push-off type .The parameters investigated were the volume fraction of fibers, the amount of stirrups crossing the shear plane, and the ratio of direct to shear stress. Test results showed that the presence of normal stress and fibres increase the first cracking load and shear transfer strength and this enhancement is more pronounced in specimens without stirrups in the shear plane for both push-off and modified push-off specimens. The fibrous specimens showed more stiffness, failed in a ductile mode, and experienced more strain capacity than plain specimens without fibres. From the present test results, a regression analysis was done and a prediction formula is proposed .

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Flat slabs are the slab without beam so it save level of the floor. The punching shear caused failure around the column area under applied load on the column, to reduce this failure shear reinforcement were used but it is not easy practically especially for low slab thickness, it can be used steel fibres in the concrete mix to increase the punching shear strength. The aim of the research to study the punching shear of flat slab of self compacting concrete ,this type of concrete used widely because it is environmental friendly. The main parameters are the reinforcement of the slab, two percent were taken with different volume percent of steel fibre (0,0.4,0.8,1.2)%.The main results obtained that the punching shear strength increased with the volume percent of fiber and steel reinforcement, it increased about 27.95% , 21.4% for slabs with reinforcement ratio =1.4%, =1.8% respectively for 1.2% fibre, and the energy absorption increased about 107% for slab with 1.2% fibre and =1.8% compared with slab without fibre. The results show also increased in ductility as the fibre content increase and the failure perimeter of the slabs is approximately circular shape and the failure perimeter increase as the fibre content increased.

The aim of this study is to compare the properties of three self-compacted concrete (SCC) mixes, with normal concrete mix. For the SCC mixes, the cement was replaced partially with either limestone dust or clinker waste dust. Compressive strength, tensile splitting, and flexural strength tests were conducted at ages of 3, 7, 14, 28, and 56 days to trace the strength development. Modulus of elasticity tests were conducted at 28-days. The test results showed that mixes containing limestone dust have better fresh properties than the other SCC mix. The compressive strength test results showed that the mix containing clinker waste powder give higher compressive strength. and mix containing eight percent limestone give higher tensile splitting strength and flexural strength than the mix has ten percent of limestone give for all curing regimes. The results showed that the modulus of elasticity is relatively lower than that for normal concrete and the voids volume in normal concrete is greater than that of SCC.