Pore Formation and Performance Enhancement of Nanopore-Rich High Porosity Aerated Cement via Nanomontmorillonite

Abstract

Nanopore-rich high porosity aerated cement (NHPAC) was prepared by introducing nanomontmorillonite slurry (NMS) into aerated cement paste, and the rheology of slurry, pore structure (air voids and microscopic pores), performance of NHPAC, and related mechanisms were investigated. The results indicated that NMS can generate rich microscopic pores in NHPAC and successfully achieve the part replacement of air void, increasing 0% to 30% of NMS rose microscopic pore porosity from 40.4% to 57.2% and from 40.5% to 54.9% for density grade of 250 and 400 kg/m3, respectively. In addition, the content of air voids below 0.5 mm increased with increasing NMS. Due to the creation of small air voids, the replacement of air voids by microscopic pores, the pozzolanic reaction of nanomontmorillonite, and the performance of NHPACs were enhanced. 20% of NMS improved 56-day compressive strength by 34.8% and 10.9%, and reduced thermal conductivity by 15.3% and 9.3% for density grades of 250 kg/m3 and 400 kg/m3, respectively. This development might allow for the use of high porosity aerated cement.