Utilization of sulfate-rich solid wastes in rural road construction in the Three Gorges Reservoir

Using the sulfate-rich solid wastes (phosphogypsum and electrolytic manganese residue [EMR]) discharged in the Three Gorges Reservoir region for rural road construction can reduce both the cost of road construction and the environmental impact of the wastes. The activation function of the sulfate-rich solid wastes composed of pozzolanic waste and acetylene sludge was investigated. Two clinker-free composite binders of phosphogypsum–fly ash–acetylene sludge and EMR–fly ash–acetylene sludge were studied. Practical rural road construction made of the composite binders was carried out. The experimental results demonstrate that the solid wastes can play an activation role in the binders without negative effect. Field investigations on the practical roads show that the compressive strength of the concrete specimens can reach 10 MPa at the end of 1 year and the road can meet the traffic requirements. It is affirmed that no negative effect on environment was detected when the solid wastes were used in the rural road.