Investigation of sustainable pervious concrete pavement performance using waste travertine aggregate and powder

Abstract

Travertine cutting generates rubble and waste powder, prompting the need for effective waste utilization. This study aims to develop travertine permeable concrete (TPC) using travertine aggregate and waste powder. An orthogonal test method assessed TPC variations in travertine powder replacement rates, aggregate grading, and void content for porosity, permeability, mechanical strength, and heavy metal adsorption ability. The void content greatly influences the amount of cementitious material and is crucial for TPC performance. To guarantee compliance with the engineering performance for fully pervious pavement, the recommended void content of TPC should not exceed 20 % to have satisfactory compressive strength and permeability. Cement replacement with 5–10 % travertine powder can satisfy engineering requirements, heavy metal adsorption, waste utilization, and CO2 emission reduction. TPC demonstrates much lower removal rates under the rapid method than the immersion method for Cd2+, Cu2+ and Pb2+, mainly due to the difference in contact time. After 25 cycles, the optimized TPC shows less mass and strength loss, demonstrating excellent freeze-thaw resistance. Furthermore, a novel lab-scale rainfall simulation system for travertine permeable concrete pavement (TPCP) was built to assess the water infiltration of TPCP. TPCP can effectively reduce runoff, reaching over 96 % within 1 h for various inflow intensities. After half an hour, the removal rates of Cd2+ and Cu2+ by TPCP were only 41.5 and 79.1 %, respectively, but TPCP achieves exceptional Pb2+ adsorption with a removal rate of over 97 % under the ternary competitive mechanism.