Strength and behavior of reinforced concrete one-way slabs with opening in flexural

This paper presents an experimental work to study the flexural behavior of reinforced concrete (RC) one way slabs with opening. Ten RC one way slabs one control slab (S1) without opening and the other nine (S2, S3, S4, S5, S6, S7, S8, S9 and S10) with opening at the center were tested by four points bending tests. The samples (S2, S3 and S4) with square aperture of (150mm, 200mm, and 250mm) side respectively, samples (S5 and S6) containing (rectangular and circular) opening, respectively. S7 slab was provided with additional rectangular bars surrounding the square opening. S8 slab was supplied with additional diagonal bars located at the edges of the square opening, S9 slab was supplied with additional rectangular and diagonal bars surrounding the opening, and S10 slab was supplied with additional double rectangular bars surrounding the square opening. However, S2 slab was not supplied with any additional bar at the opening. The experimental results showed that reinforced concrete slab with square (200mm side) opening gave a reduction of 50% in capacity compared to RC slab without opening. Among the RC slabs with opening, S9 achieved the highest capacity but the effect of additional diagonal bar was not significant.