Flexural behaviour of reinforced concrete slab with opening

Abstract

An experimental work was conducted to determine the structural performance of oneway reinforced concrete (RC) slabs with rectangular opening. 5 types of RC slabs which consist of 2 panels for each type were tested by four points bending tests. These include one control slab (S1) without opening and the other four (S2, S3, S4 and S5) with rectangular opening at the centre. S3 slabs were provided with additional rectangular bars surrounding the opening. S4 slabs were provided with additional diagonal bars located at the edges of the opening, and S5 slabs were provided with additional rectangular and diagonal bars surrounding the opening. However, S2 slabs were not provided with any additional bar at the opening. The test results indicate that RC slab with opening gave a reduction of 36% in capacity compared to RC slab without opening. Among the RC slabs with opening, S5 achieved the highest capacity but the effect of additional diagonal bar was not significant. Pure bending cracks were found at the bottom slabs between the two concentrated loads.