Investigation of mechanical strength, permeability, durability and environmental effects of pervious concrete from travertine waste material

Travertine cutting stone material has been considered a kind of solid waste, so how to effectively utilize this solid waste is worthy of more attention. This study aimed to develop travertine pervious concrete (TPC) using travertine waste and evaluate its potential applications for practical pervious concrete pavement. The orthogonal test design method was used to design TPC with different travertine aggregate replacement rates (0, 25, 50 and 100 %), water/binder ratios (0.27, 0.29, 0.31 and 0.33) and polypropylene fiber additions (0, 0.3, 0.5 and 1.0 %). The physical properties (hardened density and porosity), mechanical properties (compressive and flexural strength), water permeability and heavy metal adsorption properties were investigated. The results showed that the 28d compressive strength of the prepared TPCs reached 20.90 ∼ 37.54 MPa at a porosity of 16.15 ∼ 29.00 %, and the permeability coefficient reached a maximum of 4.59 mm/s, nearly four times higher than the initial value, and satisfies the recommended value of (CJJ/T135–2009) for pervious concrete applicable to fully permeable other roads and fully permeable sidewalk areas. Besides, TPC has an excellent ability to immobilize heavy metals, and the Pb2+ removal rate exceeds 95 %, reflecting environmental friendliness. The damage pattern of TPC specimens showed significant partial or complete fracture of the travertine aggregate compared to that of the conventional aggregate pervious concrete which was mainly damaged at the interfacial transition zone (ITZ), a difference attributed to the fragility of the travertine aggregate and the enhanced interfacial adhesion. The Optimized TPC (OTPC) specimens containing travertine replacement rate (25 %), water/binder ratio (0.27) and polypropylene fiber (0) exhibit better basic performance (6.33 % compressive strength enhancement and 26.73 % permeability improvement) and good freeze-thaw resistance ability.