摘要
对高延性纤维增韧水泥基复合材料（ECC）的高温后力学性能进行了试验研究，探讨了高温对于其抗压、抗折强度以及质量损失率的影响，并通过微观显像研究了其微观结构的劣化机理。研究结果表明：高温对ECC的质量损失率影响不严重，而高温将对ECC的力学性能产生重大影响，200℃后PVA纤维将发生熔融并挥发，抗折强度大幅降低；纤维挥发产生的孔洞直径将在40～600℃时得到扩张，导致抗压强度大幅降低；800℃后其残余抗折、抗压强度分别为原有强度的17．3％、37％；由于PVA纤维熔融挥发产生的大量孔隙减小了ECC试块在高温下发生爆裂的概率。为深入研究ECC的耐火性能及预测ECC结构构件高温后的损伤提供参考依据。
Focus on the study on the properties of engineered cementious composite after exposure to high temperatures,including compressive strength, flexural strength and mass loss ratio.In addition, the degradation mechanism of micro-structure was studied through microscopic imaging. The results showed that mechanical properties was serious effected while mass loss ratio of the ECC was not, and flexural strength significantly red after 200℃ when PVA fibers melted and evaporated, and the evaporation made the hole diameters increase after 400℃ and 600℃, which resulted in compressive strength asle significantly reduced.After 800℃ ,the residual fiexural strength and compressive strength were 17.3% and 37%, respectively.What＇s more, the probability of rupture at high temperatures reduced because of large number of pores resulted from the melting and evaporation of PVA fibers.This research will provide a reference for in-depth study of fire resistance and predicting damage of ECC structural components after high temperatures.
出处
《混凝土》
CAS
CSCD
北大核心
2011年第12期31-33,48,共4页
Concrete
基金
国家自然科学基金资助项目(59978008)
关键词
力学性能
PVA纤维
高温
质量损失率
mechanical properties
PVA fibers
high temperatures
mass loss ratio
