Effect of Adding Glass Fibre Reinforced Concrete Topping on Flexural Behaviour of Hollow Core Slab Units

This paper presents an experimental study regarding the effect of using glass fibre reinforced concrete topping on flexural capacity of hollow core precast prestressed slab units. Two glass fibre reinforced concrete (GFRC) toppings of 32 mm and 65 mm thicknesses were used on 200 mm depth hollow core slab units. Cylinder strength of hollow core slab concrete was 45.7 MPa while that of GFRC toppings was designed as 38.6 MPa. Flexural loading was applied to topped and control slabs and effect of addition of topping was studied compared to the control slabs with no topping. Results show that addition of topping can improve the flexural strength of hollow core slabs by 50% with 65 mm topping while around 20% for 32 mm topping. The increase in flexural capacity was found linear with the thickness of topping. It was also observed that flexural strength of concrete topped slabs is almost equal to the capacity of un-topped slabs of similar depth.