Influence of the aerogel/expanded perlite composite as thermal insulation aggregate on the cement-based materials: Preparation, property, and microstructure

Abstract

Aerogel/expanded perlite composite (AEP) provide an effective approach for low cost application of aerogel in building materials. AEP cement-based composites (AEPC) was prepared based on the three kinds of cement-based materials. The influences of AEP on the workability, physical and mechanical property, and microstructure of AEPC were studied. The results shown that the negative influence of the hydrophobic AEP on the workability of the AEPC fresh mixture were improved by adopting the reasonable cement-based binders, and combing with the method of KH550 modifying AEP or adding HPMC in the cement-based binders. However, the KH550 and the HPMC inhibited the hydration process of cement-based materials. The AEPC had been prepared with the dry density of 524–951 kg/m3, the compressive strength of 3.79–14.47 MPa, and the thermal conductivity of 0.1063–0.1953 W/(m·K). The AEP were able to stably exist in the AEPC without generate new hydration products in the cement matrix. Because of the stability of aerogel in the AEP and AEPC, the thermal conductivity of AEPC decreased by 10.8%~28.5% compared with the expanded perlite cement-based composites.