Study of flexural strength and leachate analysis of fly ash-lime-gypsum composite mixed with treated tire chips

The paper presents the study of flexural strength of reference mix containing fly ash +8% lime +0.9% gypsum mixed with treated tire chips along with leachate analysis. The tire chips used in this investigation were treated with water, sodium hydroxide and carbon tetra chloride. The tire chip content was varied from 5% to 15%, curing period from 7 to 180 days and cured by two different methods (in dessicator and water-filled container) of curing. The results of this study revealed that flexural strength of the reference mix mixed with treated tire chips was higher in comparison to the reference mix with dry tire chips. Flexural strength increased with the increase in curing period and change in curing method from dessicator to water-filled container. Results further reveal that flexural strength decreases with the increase in the tire chip content. Further inclusion of tire chips in the reference mix changes the cracking pattern and deflection. The results of leachate analysis reveal that the reference mix with/without treated tire chips has shown a reduction in the leachablity of sodium and zinc in comparison to pure tire chips and the reference mix, respectively. The leachablity of calcium, sulphate, manganese in comparison to pure tire chips was higher. The composite made from reference mix mixed with treated tire chips has shown a reduction in the leaching of iron in comparison to the reference mix. A low level of leaching of manganese was observed from the reference mix with and without dry/treated tire chips. Further, no evidence of presence of harmful metals like copper, lead, chromium, cadmium and nickel were found in the leachate of the composite.