Geotechnical Properties of Copper Slag, Rice Husk Ash Blended with Lime, Cement and Geopolymer—A Comparative Study

Abstract

AbstractA total of 98 experimental test results have been compared on different mixes of Copper Slag (CS), Rice Husk Ash (RHA), Lime (L), Cement (C), and Alkali Activator (AA) in order to evaluate Specific Gravity (SG) and compaction properties of these mixes. Hydrated lime, ordinary Portland cement of 43—Grade were used in this study. Sodium Silicate (SS) and Sodium Hydroxide (SH) solutions were used as activators with alkali activator ratio of 2.5 SS/SH and concentration of SH 10 M (morality) solution. The SG and compaction tests have been performed using a Pycnometer and Modified Proctor Compaction (MPC) tests. Based on the experimental results mathematical models have been constructed to estimate predicted values of SG, Maximum Dry Density (MDD), and Optimum Moisture Content (OMC). SPSS software and Microsoft Excel were used to develop mathematical models and to analyze the data. The maximum value of SG obtained was 3.37 for the combination of 95% CS + 5% RHA; the minimum SG value was obtained as 2.17 for the mix proportion of 56% CS + 35% RHA + 9% AA. Compared to all the combinations the mix with 93% of copper slag, 5% of rice husk ash, 1% of lime, and 1% of cement has shown the highest value of MDD and OMC of about 2.64 g/cc and 9.86%, respectively. These combinations may be used in highway construction, as earth filling material, construction of embankments, etc. as per Indian road congress (IRC) guidelines.KeywordsCompactionSpecific gravityLimeCementAlkali activatorMLRA