Multi-functional properties of low-carbon travertine aggregate pervious concrete modified by waste limestone powder

Abstract

The mining and crushing of limestone and travertine generate substantial quantities of powder and debris, which are typically discarded as solid waste in landfills, posing environmental concerns. To promote waste utilization, this study introduced an innovative pervious concrete combined with travertine aggregate substituting natural aggregate and limestone powder (LSP) as a cement substitute (TALPPC). Different properties of TALPPC were tested and characterized. The results showed that incorporating 5–20% LSP into TALPPC marginally decreased compressive strength, but TALPPC became lighter and had good freeze-thaw resistance. LSP's addition mitigated permeability and porosity by filling concrete pores proportional to its content. Notably, TALPPC demonstrated peak Pb2+ immobilization under the ternary competitive mechanism, with LSP enhancing heavy metal ion adsorption. The laboratory-scale TALPPC pavements displayed remarkable heavy metal adsorption capacities and significantly reduced runoff. Given its waste recycling potential, CO2 mitigation, and engineering suitability, the utilization of 15% LSP in TALPPC production was advised.

Keywords

• Pervious concrete
• Waste utilization
• Low-carbon construction
• Travertine aggregate
• Limestone powder
• Freeze-thaw resistance