To further strengthen the protective effect of aerogel cement paste (ACP) coating on self-compacting concrete (SCC) in tunnel fire under the optimal mix proportion,the effect of curing temperature (from 5 to 80 ℃,bas...To further strengthen the protective effect of aerogel cement paste (ACP) coating on self-compacting concrete (SCC) in tunnel fire under the optimal mix proportion,the effect of curing temperature (from 5 to 80 ℃,based on site construction curing temperature and surrounding rock temperature) on fire insulation of ACP was investigated.The mechanical properties,thermal conductivity and porosity of ACP were tested.The microstructure of ACP was characterized by means of SEM,XRD and TG/DTG.The results reveal that 50 ℃ is the optimal curing temperature for ACP with good mechanical properties and fire insulation.Relatively high curing temperature can facilitate hydration and pozzolanic reactions,contributing to the generation of more stable substances (such as C-S-H gels,tobermorite and thenardite,etc).ACP under excessive low curing temperature brings inhomogeneous microstructure with coarse pores,leading to producing wider and longer microcracks when it is exposed to tunnel fire.The microcracks make the heat convection and thermal radiation more significant and thus accelerate the damage of ACP under fire.In case of the less than 7% difference of thermal conductivity,dense microstructure and stable substances are more conducive to strengthening fire insulation of ACP.In practical engineering applications,the thickness of protective layer of ACP can be further optimized when ACP is cured under about 50 ℃.展开更多
A thermal insulating material is synthesized via a non-steam-cured and non-fired route by using fly-ash, sorel cement and hydrogen peroxide solution as raw material. Properties such as apparent density, compressive st...A thermal insulating material is synthesized via a non-steam-cured and non-fired route by using fly-ash, sorel cement and hydrogen peroxide solution as raw material. Properties such as apparent density, compressive strength, bending strength, thermal conductivity, water resistance, and thermal tolerance of this matrial are studied, some influencing factors on its performance discussed. This material has an apparent density of 360 kg/m^3, a compressive strength of 1.86 MPa, a thermal conduction coefficient of 0.072 W/（m·K）, a softening coefficient of 0.55, and a thermal tolerant temperature of 300 ℃. Test results show that this material is light in weight, of high strength, and good thermal insulation. In addition, neither steam-curing nor sintering is needed in producing it. Further more, large amount of fly ash is used in this material, making it a low cost and environment-friendly building material.展开更多
研究绝缘导热加成型有机硅灌封胶的制备及性能。结果表明:当采用粘度为300和1 000 m Pa·s的端乙烯基硅油以质量比40∶60复配、选用活性氢质量分数为0.005 0的含氢硅油且硅氢基/硅乙烯基摩尔比为1.2时,有机硅灌封胶的物理性能较佳;...研究绝缘导热加成型有机硅灌封胶的制备及性能。结果表明:当采用粘度为300和1 000 m Pa·s的端乙烯基硅油以质量比40∶60复配、选用活性氢质量分数为0.005 0的含氢硅油且硅氢基/硅乙烯基摩尔比为1.2时,有机硅灌封胶的物理性能较佳;当三氧化二铝用量为150份时,有机硅灌封胶具有良好的综合性能。展开更多
基金Funded by the National Natural Science Foundation of China(No.51678081)Natural Science Foundation of the Jiangsu Higher Education Institution of China(No.18KJB560001)。
文摘To further strengthen the protective effect of aerogel cement paste (ACP) coating on self-compacting concrete (SCC) in tunnel fire under the optimal mix proportion,the effect of curing temperature (from 5 to 80 ℃,based on site construction curing temperature and surrounding rock temperature) on fire insulation of ACP was investigated.The mechanical properties,thermal conductivity and porosity of ACP were tested.The microstructure of ACP was characterized by means of SEM,XRD and TG/DTG.The results reveal that 50 ℃ is the optimal curing temperature for ACP with good mechanical properties and fire insulation.Relatively high curing temperature can facilitate hydration and pozzolanic reactions,contributing to the generation of more stable substances (such as C-S-H gels,tobermorite and thenardite,etc).ACP under excessive low curing temperature brings inhomogeneous microstructure with coarse pores,leading to producing wider and longer microcracks when it is exposed to tunnel fire.The microcracks make the heat convection and thermal radiation more significant and thus accelerate the damage of ACP under fire.In case of the less than 7% difference of thermal conductivity,dense microstructure and stable substances are more conducive to strengthening fire insulation of ACP.In practical engineering applications,the thickness of protective layer of ACP can be further optimized when ACP is cured under about 50 ℃.
基金Project 20062147 supported by the Liaoning Province Natural Science Foundation of China
文摘A thermal insulating material is synthesized via a non-steam-cured and non-fired route by using fly-ash, sorel cement and hydrogen peroxide solution as raw material. Properties such as apparent density, compressive strength, bending strength, thermal conductivity, water resistance, and thermal tolerance of this matrial are studied, some influencing factors on its performance discussed. This material has an apparent density of 360 kg/m^3, a compressive strength of 1.86 MPa, a thermal conduction coefficient of 0.072 W/（m·K）, a softening coefficient of 0.55, and a thermal tolerant temperature of 300 ℃. Test results show that this material is light in weight, of high strength, and good thermal insulation. In addition, neither steam-curing nor sintering is needed in producing it. Further more, large amount of fly ash is used in this material, making it a low cost and environment-friendly building material.
文摘研究绝缘导热加成型有机硅灌封胶的制备及性能。结果表明:当采用粘度为300和1 000 m Pa·s的端乙烯基硅油以质量比40∶60复配、选用活性氢质量分数为0.005 0的含氢硅油且硅氢基/硅乙烯基摩尔比为1.2时,有机硅灌封胶的物理性能较佳;当三氧化二铝用量为150份时,有机硅灌封胶具有良好的综合性能。
