Effect of Adding Nano Starch Biopolymer on some Properties of Silica Fume Concrete

Abstract

The article describes a new method to use biopolymers (Nano starch) as an alternative to mineral admixtures in improving concrete properties, producing sustainable concrete, and reducing CO2 emissions in the atmosphere by partial replacement of cement with silica fume. The impact of nano starch as a biopolymer on certain properties of silica fume concrete In the fresh state (slump and fresh density) and In the hardened state (compressive strength, splitting tensile strength) at 7 and 28 days was researched. It has been added to silica fume concrete in various percentages of (0.5%, 1%, and 1.5%) by the weight of cement. The mix proportions were (1:2.3:2.3) (cement: sand: gravel) respectively, for all blends w/c equal 0.47, and constant percentage of ( silica fume of 15%, and superplasticizer of 0.75 percent) by the weight of cement. According to the findings, the optimal starch addition was 0.5%, which resulted in a 34% increase in compressive strength and a 31% and 21% increase in splitting tensile and flexural strength of concrete, respectively. Slump increased by 19%, and fresh density increased by 4% when the starch powder was added at a concentration of 1.5%.