Proportioning and characterization of Portland cement-based ultra-lightweight foam concretes

Due to desirable thermal insulation properties, superior fire-resistant and higher durability, ultra-light-weight foam concretes are recommended to achieve energy efficiency in buildings. Generally, aluminate cement, sulphoaluminate cement and other quick hardening cementitious materials are used to control the stability of air-voids in foam concretes. These special cementitious materials are relatively expensive and not universally available, retarding the application and popularization of foam concretes. In the present study, the proportioning and properties of Portland cement-based ultra-lightweight foam concrete were investigated. The results show that ultra-lightweight foam concretes with apparent density of 100-300 kg/m(3) can be prepared using Portland cement, fly ash, hydrogen peroxide and chemical admixtures. Collapse and air-voids escape can be avoided by adding thickening agent and foam stabilizing emulsion into foam concretes. Most of pores in ultra-lightweight foam concretes were non-connected pores with size of 2.0-4.0 mm, resulting in a lower thermal conductivity, desirable compressive and tensile strengths. (C) 2015 Elsevier Ltd. All rights reserved.