Development of lightweight strain hardening cementitious composite for structural retrofit and energy efficiency improvement of unreinforced masonry housings

Abstract

The paper develops a lightweight strain-hardening cementitious composite (LSHCC) using fragile hollow glass micro-bubbles (3M-S15) and 1.5–1.75% PVA fibers, and reports its thermal, mechanical, and durability properties together with its effectiveness for retrofitting unreinforced masonry (URM) walls. The LSHCC (wet density ≈1,300–1,400 kg/m³) achieved tensile strength ≈3 MPa with 2–4% tensile ductility, compressive strength 14–31 MPa, and thermal conductivity 0.34–0.51 W/m·K. Nonlinear pushover simulations of URM walls strengthened with 10-mm LSHCC layers showed ductility increases of 38% and 72% in-plane (for mixes with 2.2% and 4.4% tensile ductility) and ≈164% out-of-plane, while durability tests indicated chloride diffusivity reductions (due to FA/GGBS binding) but higher carbonation rates versus normal concrete. These results indicate LSHCC can simultaneously enhance seismic performance and building energy efficiency of URM housings., :contentReference[oaicite:0]{index=0}