Effects of Curing Regimes on Tunnel Fire Resistance of Self-Compacting Concrete Coated with Aerogel Cement Paste

Abstract

Abstract: To further strengthen the protective effect of aerogel cement paste (ACP) coating for self-compacting concrete (SCC) in a simulated tunnel fire (1 100 ℃, 2.5 h), the influence of wet curing time (7 d to 28 d, based on site construction curing regimes) on tunnel fire resistance of SCC coated with ACP was investigated. The experiment results show that the non-composite C40 SCC burst after simulated tunnel fire, with 116 times of burst and 0 residual compressive strength. In contrast, SCC coated with ACP under different curing regimes have no burst. The more loose microstructure of ACP, the more microcracks are generated under fire. Microcracks accelerate the damage of cement paste and reduce fire resistance of ACP. Under all curing regimes, the thermal conductivity of ACP under 14 d wet curing is the lowest (0.179 W/(m·K)), and the residual compressive strength of SCC coated with ACP under this curing regime is the highest (13.5 MPa). 14 d wet curing is the optimal curing regime.

Key words: curing regime, aerogel cement paste, self-compacting concrete, tunnel fire, residual compressive strength

CLC Number:

TU528

XU Donghang, ZHU Pinghua, CHEN Chunhong, LIU Hui, LIU Shaofeng. Effects of Curing Regimes on Tunnel Fire Resistance of Self-Compacting Concrete Coated with Aerogel Cement Paste[J]. BULLETIN OF THE CHINESE CERAMIC SOCIETY, 2021, 40(2): 423-430.

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