自密实混凝土结构抗火研究进展

对近年来自密实混凝土结构抗火研究进展作了总结，包括自密实混凝土高温材性试验和足尺自密实混凝土构件的抗火性能试验研究。从自密实混凝土高温下和高温后的力学性能、热工性能和应力-应变关系等方面入手，总结和分析了已有研究所取得的成果和尚存的一些问题。分析表明：高温下自密实混凝土质量和抗压强度损失严重，通过添加不同添加剂可使其得到改善。由于其密度高，在高温下自密实混凝土比普通混凝土更易发生高温爆裂，加入纤维可以有效抑制爆裂但会降低抗压强度。高温爆裂的抑制和抗压强度降低的平衡研究，自密实混凝土结构高温后损伤鉴定和修复加固，以及自密实混凝土加固结构的防火保护措施研究等是今后一段时间自密实混凝土结构抗火研究领域值得关注的课题。

Progress of research on fire resistance of self-compacting concrete structures

This paper presents the progress of research on fire resistance of self-compacting concrete structures, including the experimental investigations on the mechanical properties of the self-compacting concrete subjected to elevated temperatures and the fire resistance performance of full-scale specimens. The positive results and remaining problems are summarized and analyzed in terms of the mechanical properties, thermal performance and constitutive relationship of self-compacting concrete at and after high temperatures. Analysis results show that the mass and strength of the self-compacting concrete will severely decrease as the temperature increases but can be improved by adding different additives. The self-compacting concrete is more likely to occur explosive spalling than normal concrete subjected to high temperatures due to its high density. Adding fiber into concrete can reduce the probability of explosive spalling but slao decrease the strength of the self-compacting concrete. The balance research between the reduction of strength and explosive spalling under high temperatures, damage identification, repair and strengthening of the self-compacting concrete structures after high temperatures and fire protection measure researches for structures strengthened with the self-compacting concrete are still needed to be studied in the future.