Preparation and characterization of high porosity cement-based foam material

• A physical air-entraining method has been reported.
• The properties of high porosity cement-based foam materials have been investigated.
• Influence of water–cement ratio and HPMC on material properties has been analyzed.
• Pore structure formation mechanism has been clarified.

High porosity cement-based foam materials were prepared through physical air-entraining method and the pore structure and the properties of materials were characterized. The results show that water–cement ratio and Hydroxypropyl Methyl Cellulose (HPMC) content have crucial influence on material properties. When the water–cement ratio was 0.9 and the content of HPMC was 0.4%, the cement-based foam material with the porosity of 94.33% and thermal conductivity value of 0.049 W/(m K) could be obtained. The formation mechanism of pore structure was analyzed that water–cement ratio and HPMC content affect the bubble film toughness which influence on material properties.