养护方式对气凝胶砂浆复合自密实混凝土隧道火灾抗力的影响

摘要/Abstract

摘要： 为了更好地提升气凝胶砂浆(Aerogel Cement Paste,ACP)在模拟隧道火灾(1 100 ℃,2.5 h)中对自密实混凝土(Self-Compacting Concrete,SCC)的保护作用,以现场施工养护方法为基准,研究了湿养时间(7 d至28 d)对ACP复合SCC隧道火灾抗力的影响。结果表明:非复合C40 SCC在隧道火灾试验中发生爆裂,爆裂次数为116次,残余抗压强度为0 MPa,而不同养护方式的ACP复合SCC均未发生爆裂;ACP微观结构越疏松,在高温下产生的微裂纹就越多,这会加速水泥浆体的损伤,降低ACP耐火性能;14 d湿养的ACP的导热系数最低,为0.179 W/(m·K),该养护方式下的ACP复合SCC的残余抗压强度最高,为13.5 MPa,14 d湿养为最优养护方式。

关键词: 养护方式, 气凝胶砂浆, 自密实混凝土, 隧道火灾, 残余抗压强度

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

中图分类号:

TU528

徐东航, 朱平华, 陈春红, 刘惠, 刘少峰. 养护方式对气凝胶砂浆复合自密实混凝土隧道火灾抗力的影响[J]. 硅酸盐通报, 2021, 40(2): 423-430.

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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