摘要
超高性能混凝土(UHPC)具有优异的强度、韧度、耐久及抗裂性能。但UHPC在高温下易发生爆裂,由此可能严重影响其力学性能。对高温后UHPC的残余受压性能进行了试验研究。试验参数包括受火温度、纤维类型和养护条件。评估了UHPC高温后的抗压强度、弹性模量和应力-应变关系。结果表明,随着受火温度的升高,UHPC的残余抗压强度和弹性模量逐渐下降,延性逐渐提高。无纤维试件和POM纤维掺量较少试件(0.33%)在500℃时发生完全爆裂。与这两类试件相比,UHPC中添加钢纤维和0.33%含量的PP纤维可显著提高混凝土的残余受压性能及降低爆裂风险。利用这些数据,提出以温度为变量表示的UHPC高温后残余受压性能的函数关系,以评估UHPC结构的耐火性。
Ultra-high performance concrete(UHPC)has distinguished high strength,toughness,durability and cracking-resistance capacities.However,UHPC is prone to explosive spalling at high temperatures,which may significantly affects its mechanical properties.In this study,the residual compressive performances of UHPC after high temperature exposure was investigated experimentally.The test parameters included fire temperature,fiber type and curing condition.The compressive strength,elastic modulus and stress-strain relationship of UHPC after different thermal exposures were evaluated.The results show that the residual compressive strength and elastic modulus of UHPC decrease and the ductility increases with the increase of the fire temperature.The specimens containing no fibers and those with POM fibers of less 0.33%dosage spalled completely after 500℃exposure.In comparison with these two types of specimens,the combined addition of steel fiber and 0.33%PP fiber in UHPC can significantly improve the residual compressive performances of UHPC and reduce its spalling risk.Using these data,the functional relationship of the residual compressive performances of UHPC after high temperature exposure in temperature variable is proposed to evaluate the fire resistance of UHPC structure.
作者
温沛纲
高晨源
WEN Peigang;GAO Chenyuan(Poly South China Industrial Co.,Ltd.,Foshan 528253,China;Power China Urban Planning and Design Institute,Guangzhou 511458,China)
出处
《广东土木与建筑》
2022年第10期122-126,共5页
Guangdong Architecture Civil Engineering
关键词
超高性能混凝土
残余受压性能
钢纤维
PP纤维
POM纤维
ultra-high performance concrete
residual compressive performance
steel fiber
PP fiber
POM fiber
