Engineering and sustainability performance of geopolymer concrete blended with sodium silicate effluent

Abstract

Geopolymer concrete (GPC), is found to be one of the suitable alternatives, which reduces the carbon emission due to utilization industrial by-products. Due to over use of conventional filler materials, there exists a demand. Therefore, conventional coarse aggregate was substituted with sodium silicate effluent (SSE). The SSE was employed in the range from 0 % to 50 %; to examine the engineering performance of GPC. Increasing the dose of SSE decreases the slump from 75 mm to 60 mm for the concrete with 50 % SSE, and also decreases the strength from 36 MPa (concrete with 0 % SSE) to 17 MPa (concrete with 50 % SSE). The GPC samples with and without SSE were immersed in acid and salt solutions; the acid used in the present study was sulfuric acid (H₂SO₄) and nitric acid (HNO₃). The salts employed for the study were magnesium sulfate (MgSO₄) and sodium chloride (NaCl). Approximately, 43 % of the original concrete (0 % SSE) strength was degraded after 360-d of H₂SO₄ immersion, whereas 50 % SSE shows a loss of 71 %. For HNO₃ immersion, the loss was found to be 40.8 % for 0 % SSE mix and 55 % for 50 % SSE mix. 35 % and 42 % loss in strength was observed for the concrete with 0 % and 50 % SSE after exposed to MgSO₄ solution, and 25–35 % loss was seen for the mix with and without SSE.