Physical and mechanical properties of Alkali Activated Concrete Made from Locally Available Geo-material (white soil „Nech Afer‟

Abstract

Cement is one of the main constituent materials in concrete production. From production of cement large amount of CO2 emitted to the atmosphere. The utilization of comcent is increasing over time and this causes an environmental impact. Replacing this material with other eco friendly cementing materials is a global concern. Different researchers introduce alkali activated concrete using local geo-material and an industrial by-product as a cementing agent without influencing the concrete property. Therefore, this research aimed to investigate the capacity of alkali-activated concrete made from locally available geo-material (white soil ‘Nech Afer’ )as a partial replacement of Portland pozolanic cement in C-20/25 concrete. The pozolanic nature of the geo-material (white soil ‘Nech Afer’) was examined by chemical composition test. A 10%, 20%, 30%, 40%, and 50% replacement was carried out and investigated for workability, compressive strength, and splitting tensile strength test and compared with the control sample. From this research, it was observed that white soil ‘Nech Afer’ has a pozolanic property. Therefore, using white soil ‘Nech Afer’ with an alkali activator in partial replacement of cement in geopolymer concrete production was possible. The compressive strength test results in 40.38MPa at 10% replacement, 28.33Mpa at 40%, and 22.95MPa at 50% replacement were obtained. Whereas, for the control sample, 28.75MPa compressive strength results were obtained on the 28th day. But, the workability of the alkali-activated white soil ‘Nech Afer’concrete decreases as the percentage of replacement increases from the fresh property of concrete. Therefore, it can be concluded that the optimum percentage of replacement of cement with alkali-activated white soil ‘Nech Afer’ in C-25 concrete is 40%. And, it was observed that 50% replacement of cement with alkali-activated white soil ‘Nech Afer’ may use in low-grade concrete production. Alkali-activated white soil ‘Nech Afer’ concrete has low workability compared to normal fresh concrete.