Utilizing Mine Tailings as Substitute Construction Material: The Use of Waste Materials in Roller Compacted Concrete

摘要

Mine tailings (MT) have been used in previous studies as substitute construction material to recycle waste products, especially in hollow blocks and bricks production and as masonry mortar. This study investigated the use of Philex copper-gold mine tailings (PCGMT) in roller compacted concrete (RCC) production, a mining waste material consisting of finely grinded siliceous particles was obtained from Tailings Pond number 2 (TP2) of a Philippine copper and gold mining company. A comprehensive experimental program was conducted to investigate the comparative compressive strength of RCC containing Porac sand (RCCPS) and RCC with copper-gold mine tailings (RCCCGMT), and the durability of RCC with copper-gold mine tailings and fly-ash (RCCCGMTFA). Varying mixtures of RCCPS and RCCCGMT with very low, low, medium, and high cement contents were casted and tested. The compressive strength attained at 28 days by RCCPS and RCCCGMT ranges from 17 to 37 Mega Pascal (MPa) and 17 to 28 Mpa, respectively. The obtained values indicate that the latter requires greater amount of cement and the mixtures with compressive strength values greater than 25 Mpa are acceptable for concrete pavement use. The durability of RCCCGMTFA with medium cement content was evaluated by subjecting the specimens to an alternate wetting and drying cycles. After 15 cycles, a remaining strength of 18.7 MPa was obtained which indicated that it could endure stresses due to weather changes in the Philippines. Results show that PCGMT in TP2 are viable sand or fine aggregates substitute in RCC.