Integrating recycled pervious blocks into urban drainage systems: a PCSWMM-based assessment of low-impact development potential

Abstract

Urban flooding remains a major concern in rapidly urbanizing regions where increasing imperviousness, compounded by limited drainage capacity, exacerbate the magnitude and severity of flooding. Sustainable, green infrastructure, or low impact development (LID) technologies are needed as part of an integrated grey-green approach to enhance urban flood management, particularly in tropical, Global South countries. To address this need for improved green infrastructure, our study demonstrates the fabrication of recycled pervious concrete blocks from construction waste and assesses hydrological performance PCSWMM modeling approach. Fifteen block configurations, developed from a Box–Behnken experimental design, were tested for permeability, absorption, and compressive strength. A mix with 50–60% recycled coarse aggregate (RCA) with a 120 mm thickness achieved a balanced performance, combining high permeability (> 1,800 mm/h) with structural adequacy (compressive strength > 2.5 MPa). These optimized parameters were incorporated into a PCSWMM model of a flood-prone catchment in Bangkok, Thailand. PCSWMM results showed that on a catchment-scale basis, runoff reduction is expected to be greater than 44% under design storm conditions, with the 100% RCA mix achieving 46% reduction but lacking sufficient strength for practical use. The study establishes an original modeling framework that links laboratory optimization with urban-scale flood simulations to provide a scalable approach for evaluating low impact development strategies. Beyond technical feasibility, RCA reuse represents a circular construction and economy approach to improved urban infrastructure by reducing demand for virgin aggregates and diverting demolition waste from landfills.