About the author:

1. China Railway Seventh Bureau Group Xi’an Railway Engineering Co., Ltd., Xi’an, Shaanxi 710032, China;2. School of Civil Engineering, Xi’an University of Architecture and Technology, Xi’an,Shaanxi 710055, China

Abstract:

This paper addresses the issue of insufficient strength in pervious concrete made with recycledaggregate by optimizing its performance through the combined incorporation of polyvinyl alcohol （PVA）fibers and basalt fibers. A dual⁃fiber mixing scheme with varying dosages was adopted, and theenhancement mechanism and comprehensive performance effects were systematically investigated using X⁃ray diffraction （XRD）， scanning electron microscopy（SEM）， and physical⁃mechanical property tests.The results indicate that fiber incorporation consumes cement hydration products, particularly Ca（OH）2 ,and improves the compactness of the microstructure. The increase in compressive strength wassignificantly higher than that of flexural strength. The permeability coefficient and porosity exhibited aregular decreasing trend with increasing fiber content,while still meeting the basic requirements ofpervious materials. A comprehensive evaluation based on grey correlation theory and the entropyweightmethod revealed that the optimal performance was achieved when both PVA and basalt fibers wereincorporated at 0. 1%,yielding an evaluation index of 93.9%. At this dosage, the 28⁃day compressivestrength reached 24.5MPa, and the permeability coefficient remained at 2.1mm / s, achieving asynergistic enhancement of mechanical properties and permeability performance.