Investigation on the physical, mechanical, and durability properties of ductile aerogel powder cement-based composites

Abstract

This study incorporated aerogel powder into cement-based composites to fabricate a ductile aerogel-powder–cement composite (DACC) with combined ductility and thermal insulation properties. Porosity characterization, thermal conductivity, compressive strength, flexural strength, and tensile strength tests were performed, followed by freeze–thaw cycling and Na₂SO₄ immersion evaluations. Results indicate that as aerogel powder content increased from 0 % to 10 %, DACC density decreased from 1.767 to 1.245 g/cm³ . At 2 %, 4 %, and 6 % aerogel content, compressive strength exceeded 20 MPa while maintaining good ductility and insulation performance. With 10 % aerogel, compressive strength dropped to 7.2 MPa and thermal conductivity reached as low as 0.269 W/(m·K). After 90 freeze–thaw cycles, DACC-10 % exhibited a mass loss of 1.76 % and an 89.2 % reduction in compressive strength. Under sulfate erosion, increasing aerogel content from 2 % to 10 % led to a 2 %–11.6 % improvement in compressive strength. Scanning electron microscopy (SEM) revealed three mechanisms of aerogel powder within the matrix—fiber–mortar–aerogel (FMA), pore–aerogel (PA), and mortar–aerogel (MA)—clarifying their respective influences on DACC performance. This research provides an effective approach for the engineering application of aerogel-powder cement-based composites.