The results of testing two simply and three continuously supported concrete beams

Test results show that increasing the CFRP reinforcement ratio of the bottom layer of simply and continuously supported concrete beams is a key factor in enhancing the load capacity and controlling deflection. Continuous concrete beams reinforced with CFRP bars exhibited a remarkable wide crack over the middle support that significantly influenced their behaviour. The load capacity and deflection of CFRP simply supported concrete beams are reasonably predicted using the ACI 440.1R-06 equations.However, the potential capabilities of these equations for predicting the load capacity and deflection of continuous CFRP reinforced concrete beams have been adversely affected by the de-bonding of top CFRP bars from concrete.

No abstract

Punching shear is the most important problem in flat slabs, which usually required reducing the self-weight of the slab. A lightweight concrete as well as the bubble deck technology were used to allow for lighter self-weight of the structure. This study aims to investigate the use of lightweight aggregate concrete (LWAC) with the bubble deck technology in flat slab. The behavior of two- way LWAC voided slab (with and without shear reinforcement) under punching shear effect with respect to solid normal weight and solid LWAC specimen were studded. The behavior of six specimens having the same dimensions, slab thickness and flexural steel reinforcement were studded. The main changed variables were concrete type, percent of void and punching shear reinforcement existence. The results show that the load carrying capacity for light weight aggregate concrete voided slab without shear reinforcement decreased by (60%, 53%) with respect to solid normal weight and solid LWAC slabs without shear reinforcement respectively. In addition, the load carrying capacity for LWAC voided slab with shear reinforcement decrease by (67%, 47%) with respect to solid normal weight, solid LWAC slabs with shear reinforcement respectively. Also, for lightweight aggregate concrete, solid and voided slab, shear reinforcement existence did not significantly increase the slab capacity for punching shear. But cause a reduction in maximum deflection with respect to slabs without shear reinforcement.