Experimental Investigation on Morphological and Mechanical Behavior of Glass Fibered Concrete with Partial Replacement of Cement by Bentonite

Abstract

Glass fiber reinforced concrete is a type of concrete incorporates thinly chopped glass strand to improve the strength of concrete. For further enhancement of durability and sustainability pozzolanic materials used as cement partial replacement in concrete. Therefore, the current study aimed to investigate incorporation of glass fiber as a reinforcement agent and bentonite as pozzolanic supplementary cementitious material along with its effect on workability, compressive strength, flexural strength, split tensile strength and microstructure of concrete with its environmental and economic implications. The amount of glass fiber is determined by altering the glass fiber with 0.3%, 0.5%, 0.7% and 1% by weight of concrete material. Maximum compressive and flexural strength obtained at 0.5% addition of glass fiber as result 1.5 % increment in compressive strength and 29.4 % enhancement in flexural strength achieved. Then it hybrid with calcined bentonite calcined at 7000 c which have silicon content of 65.34 %. The control mix was made from a mixture of cement, water, glass fiber, fine and coarse aggregate to attain 25 MPa according to ACI standard, whereas the replacement mix was made with 0.5% glass fiber and 5%, 10%, and 15% and 20% bentonite by the weight of cement. Maximum compressive strength obtain at 10%BN replacement which yield 3.94% improvement and the flexural strength improved by 0.88 after 56 day of curing. Therefor 0.5% GF with 10% BN taken as the optimal replacement amount to enhance both compressive strength and flexural strength. In micro structural analysis additional secondary cementitious materials called Pumpellyite observed due to the pozzolanic reaction between silicon in bentonite and calcium hydro oxide in cement. The SEM shows compacted dens and less cracked with high C-H and C-S-H amount in replaced mix. As conclusion, 0.5% glass fiber with 10% bentonite replacement of cement can collaborate together to enhance the strength of concrete while reducing the environmental impact of cement manufacturing and the replacement reduce initial production cost of glass fiber concrete by 3.72%.