Performance Optimization and Multivariate Analysis of Hybrid Fibre Reinforced Microstructure Refined Pervious Concrete using Advanced Statistical Approaches

Abstract

Urbanization and infrastructure development have significantly altered natural landscapes, replacing permeable terrains with impervious materials. This transformation disrupts the natural water cycle, preventing rainwater from infiltrating the ground to recharge aquifers and sustain natural water flows. Instead, rainwater accumulates on surfaces, leading to increased runoff. Incorporating permeable materials into infrastructure allows water to infiltrate through the surface, naturally filtering pollutants before they reach local water bodies, thereby enhancing water quality and protecting aquatic ecosystems. Additionally, permeable surfaces help mitigate the urban heat island effect by reducing heat retention in urban areas. Pervious concrete (PC) is a specialized concrete featuring a highly interconnected pore structure, with void content typically ranging from 15% to 35%. Its porous and interconnected structure facilitates efficient water drainage through the matrix, offering a sustainable solution for stormwater management. However, PC faces certain challenges and limitations. Its compressive strength is lower than that of conventional concrete, limiting its use in high-load applications. Furthermore, pervious concrete requires regular maintenance to prevent clogging caused by debris accumulation, which can reduce its permeability over time. The present study addresses three methodologies for strength enhancement of pervious concrete by incorporating hybrid fibre, mesh reinforcement and microstructure refinement by CSH seeding. The mechanical and durability properties of pervious concrete are influenced by its void characteristics and the properties of the cementitious paste. Fibre addition can enhance the cementitious paste, but a single type of fibre may not provide sufficient improvement. Therefore, this study employs a basalt-steel wool hybrid fibre system to enhance the properties of pervious concrete. A Box-Behnken design of experiments is utilized to develop higher-order response surfaces with fewer