Eco-friendly strain-hardening cementitious composites with recycled PET fine aggregate: Mechanical behavior and environmental benefits

The production of strain-hardening cementitious composites (SHCC) heavily relies on natural fine aggregates. This study employs recycled PET fine aggregates to prepare PET-modified SHCC (P-SHCC). The physical properties and mechanical behavior of P-SHCC with different PET volume replacement ratios (0 %, 25 %, 50 %, 75 %, and 100 %) are experimentally investigated. The microstructures were examined to analyze the impact of additional defects induced by the interfacial transition zone between recycled PET and cementitious matrix. The multiple cracking behavior was discussed based on the crack parameters. The results indicate that the incorporation of PET significantly enhances the ultimate strain and crack control capability of SHCC while reducing the material's density. Furthermore, energy consumption, carbon emission, and comprehensive environmental indexes were employed to analyze the environmental benefits. The findings demonstrate the feasibility of preparing SHCC with recycled PET fine aggregate, particularly in enhancing the strain capacity and environmental benefits. • Developed PET-modified SHCC with excellent mechanical properties and outstanding environmental benefits. • PET aggregate optimizes the tensile ductility, multiple cracking behavior, and energy absorption of SHCC. • Using recycled PET aggregate effectively reduced the energy consumption and carbon emissions of SHCC.