EXPLORING THE USAGE OF LITHIUM MINING TAILING CLAY (LMTC) IN CONSTRUCTION MATERIALS

Abstract

Asphalt binders and Portland cement are the most expensive constituents in paving materials. Efforts to reduce costs while minimizing the carbon footprint have driven research into alternative materials. This preliminary study explores the properties of asphalt binders and Portland cement concrete mixtures modified with varying percentages of lithium mining tailing clay (LMTC), a by-product of lithium extraction. LMTC was also evaluated as a substitute modifier to calcium carbonate (CaCO3) in air-blown binders. To prepare the LMTC-modified binders, a mechanical mixer set at 5000 rpm was used, and the optimal mixing time was determined. Asphalt binders with performance grades (PG) 58-28 and 64-28M were blended with four different percentages of LMTC. Similarly, the air-blown binder was modified with two percentages of LMTC and CaCO3. The rheological properties of the modified binders were analyzed, and the results showed that LMTC and CaCO3 decreased the penetration values and increased the viscosity. Performance tests such as the IDEAL CT and Hamburg Wheel Tracking Tests (HWTT) showed that LMTC enhanced rutting resistance but reduced cracking resistance. Dynamic Shear Rheometer (DSR) testing indicated improvement in the PG, leading to higher resistance to permanent deformation. The use of LMTC in concrete mixtures was also investigated by substituting a portion of cement with LMTC at three different percentages. Tests were conducted to evaluate the concrete slump, compressive, and flexural strength. Results showed that increasing LMTC content decreased compressive strength and slump height. However, the flexural strength for the 5% LMTC concrete mix was comparable to the control mixture and increased slightly at higher LMTC levels. Overall, the findings highlight the potential use of LMTC as an alternative material in asphalt binders and concrete mixtures with promising effects. However, further optimization is needed to balance performance. Once performance enhancements are achieved, it will be essential to quantify the environmental benefits through a comprehensive evaluation, ensuring its contribution to sustainable paving materials