Acid effect on permeable polymer concrete containing different resin and aggregate types

Abstract

Degradation of permeable concretes due to chemical effects under outdoor conditions is one of the most important problems affecting permeability. In this study, resin-based binders were used as an alternative solution to this problem and permeable concretes with sustainable performance were obtained. Resin-based binders offer an alternative to traditional cementitious materials in acidic and coastal environments due to their superior resistance to moisture and chemical degradation. In this study, the mechanical and microstructural performance of polymer permeable concrete (PPC) made with polyester and epoxy resins and different aggregate types (calcite and basalt) under long-term acid exposure was investigated. Specimens were exposed to 10 % hydrochloric acid solution for 90 and 180 days and flexural, compressive, and splitting tensile strengths were evaluated. The results showed that polyester-based PPC with calcite aggregates exhibited up to 90 % loss of flexural strength and 60 % loss of compressive strength, while epoxy-based PPC with basalt aggregates retained 55 % of flexural strength and 40 % of compressive strength after 180 days. Hydraulic permeability decreased by up to 25 % due to acid-induced microstructural degradation. Micro-CT and SEM-EDS analyses revealed increased microcrack formation in polyester-based samples, while epoxy-based PPC showed better structural integrity. Machine learning regression analysis successfully predicted the permeability changes. These results highlight the superior acid resistance of epoxy-based PPC, especially with basalt aggregates, and support its potential use in infrastructure exposed to aggressive environments.