Assessment of Impact Strength of Two-layer Fibrous Concrete Slab Using Polypropylene & Steel Fiber with Mineral Admixture

Abstract

Introduction. The impact strength through of Two-layer (600 mm × 600 mm × 60 mm) concrete slab was experimentally investigated by the following method using Weight falling test (ACI committee 544). Result. Nine numbers of slab specimens were cast (S1 to S9), with one specimen (S1) was normal plain cement concrete slab (control specimen). The purpose of the study, The addition of Polypropylene fibre (PPF) in the top 30 mm depth of the slab was from 0.2 % to 0.8 % in step of 0.2 % and the addition of hooked end steel fibre (SF) in the bottom 30 mm depth of the slab was from 0.5 % to 2 % in step of 0.5 % for the other two layered slab specimens (S2 to S9). Also, a fixed 20 % (out of the total requirement of the binder) of mineral admixture namely Ground Granulated Blast Furnace Slag (GGBS) was used as a partial replacement of binder in all the slab specimens. Each specimen was tested under weight falling test. The number of blows required to obtain final crack failures in specimens was 30, 98, 168, 125, 252, 102, 153, 245 and 46 respectively for S1 to S9. Conclusions. The comparative analysis of crack pattern and impact strength of 2-layer fibre reinforced concrete slab specimens (S2 to S9) were presented. The performance of slab specimen S5 was the best among other slab specimen and it had absorbed more impact energy and controlled crack less than the normal plain cement concrete slab specimen (S1).