Experimental Study On High-temperature Resistant Performance And Application Of Aerogel-incorporated Cementitious Composites

No smoking and toxic gases are produced when the cement is exposed to fire,while the physical properties and chemical properties will change and the construction will be destroyed.Significant casualties and property losses will be caused as the durability and safety of cementitious construction decrease.Aerogel is taken as a novel thermal insulation material for its low thermal conductivity(0.017 W/m · K,lower than that of Air 0.026 W/m·K).The ultra high toughness cementitious composites(UHTCC for short)with high strength and toughness are developed by Xu Shilang.To enhance the thermal insulation of UHTCC,aerogel composites consist of aerogel and fibers are added.The feasibility of the integration of Thermal insulation,fire prevention,structure performance for aerogel-incorporated cementitious composites(ACC for short)is investigated.1.20 vol%,30 vol%or 40 vol%of aerogel composites are added in the matrix of UHTCC,and the lowest thermal conductivity of ACC is 0.2614 W/m · K.The compressive strength and flexure strength are 9.82 MPa and 3.33MPa respectively with no specimen burst under high temperature(the temperature rising as IS0834)for 1h.2.A novel aerogel-incorporated cementitious composite board(ACCB for short)is designed according to the specification(JC/T1055-2007)-Fiber Reinforced Cementitious Sandwich Composite Panels.The compressive strength,flexure strength,and thermal conductivity of ACCB are calculated by ANSYS,which conform to the requirements of the specification.3.The temperatures inside of specimens of ACC(with 20 vol%,30 vol%or 40 vol%of aerogel composites)are tested under under high temperature as IS0834.The heat-shielding properties of ACC are investigated and an internal T-t(temperature and time)model of thick type fireproof material under fire is established.4.The fireproof properties of ACC with 40 vol%aerogel composites painted on the wall are tested under fire.Compared to the Sichuan Tianfu fireproof materials(STF for short),the ACC shows excellent mechanical and fireproof performances.5.The distribution of temperature of ACCB with 40 vol%aerogel composites under fire is calculated by ANSYS.The ACCB shows outstanding heat-shielding property(relative to concrete)for the temperature of sandwich layer of ACCB is still lower than 400?.6.The microstructures of aerogel,aerogel composites,ACC,UHTCC and STF are scanned by environment scanning electron microscope(ESEM),and mechanism of aerogel is investigated.