普通强度高性能混凝土的高温性能试验研究

EXPERIMENTAL RESEARCH ON HIGH TEMPERATURE PROPERTIES OF NORMAL STRENGTH HIGH PERFORMANCE CONCRETE

为确保混凝土结构的抗火性,对普通强度高性能混凝土高温性能进行试验,探讨普通强度高性能混凝土的高温爆裂与力学性能。结果表明,普强高性能混凝土与高强高性能混凝土类似,湿含量和密实度是影响其高温爆裂的主要因素。当湿含量超过临界值时,爆裂几率随湿含量上升而增大;混凝土越密实,爆裂越严重。体积分数0.05%的聚丙烯纤维可防止普强高性能混凝土发生高温爆裂,纤维掺量越高,高温损伤程度越小。聚丙烯纤维对残余力学性能有一定的改善作用。

Tests were conducted on high temperature properties of normal strength high-performance concrete to explore its explosive spalling and mechanical properties at high temperature,to ensure satisfactory fire resistance of concrete structures.The results reveal that both moisture content and density are the two main factors influencing the spalling.When moisture content is over a critical value,the higher the moisture content,the more the spalling frequency.The more dense the concrete,the greater the degree of spalling.Polypropylene fiber at a volume fraction of 0.05 % can prohibit the occurrence of spalling of normal strength high-performance concrete.Moreover,the higher the fiber dosage,the less the thermal damage.Polypropylene fiber has also improvement in residual mechanical properties of concrete subjected to high temperature.