Preparation of high-performance thermal insulation composite material from alkali-activated binders, foam, hollow glass microspheres and aerogel

Herein, a high-performance thermal insulation composite material was prepared by adding physical foaming agent (FA), hollow glass microspheres (HGMs) and aerogel (AG) with alkali-activated binders (AABs) as the matrix. The results of orthogonal experiments revealed that AG has the greatest effect on thermal conductivity, followed by the effect of FA and HGMs. The thermal conductivity value of AABs was reduced from 0.6057 to 0.0870 W/(m.K) at an AG dosage of 4 g (42.48 kg/m(3)) in the single factor experiments. The effect of compressive strength followed an order of: HGMs < FA < AG. Under the temperature condition of 400-800 ?, the FA exacerbated the linear shrinkage of the sample, HGMs inhibited the linear shrinkage at 400 degrees C and 600 degrees C, and exacerbated it at 800 degrees C, while AG inhibited the linear shrinkage. X-ray diffraction and scanning electron mi-croscopy analyses revealed that the sample maintained stable performance below 800 degrees. Orthogonal experiment results concluded that the optimal level combination was 6 g FA, 6 g HGMs and 3 g AG (A6B6C3) and exhibited the minimal thermal conductivity (0.0434 W/(m.K)). The compressive strength of A6B6C3 at 30 degrees C was 0.38 MPa, which gradually increased with temperature, reaching the maximum of 0.79 MPa at 800 degrees C. This composite can meet the thermal insulation, mechanical and high temperature resistance properties. In addition, accredited to simple preparation process, short curing period, and low cost, this approach can be deemed of great signifi-cance for applications in composite thermal insulation materials in nuclear power plants and other key areas.