摘要
为了研究高延性混凝土(HDC)抗紫外线老化性能,采用紫外线侵蚀试验方法,对HDC试块以30d为一个周期进行了8个周期的紫外线照射,研究其抗侵蚀性能。通过对34组HDC和NC试块进行单轴受压试验,观察不同龄期紫外线侵蚀后HDC的表观特征,获得各项基本力学指标,包括极限承载力、峰值应变。试验结果表明,经过240d紫外线照射后,HDC和NC试块表面均无明显变化;但是混凝土材料内部碳化反应速度加快,碳酸钙含量升高,混凝土的水化反应减弱;HDC与NC试块的抗压强度降低率增长均呈先上升后下降趋势,HDC较NC的抗压强度降低率最大提高2.22%;紫外线侵蚀会导致HDC内部的纤维外层损伤造成纤维共价键的断裂,而HDC属于纤维复合材料,对HDC宏观性能的影响反映在抗压强度和弹性模量的降低上。
In order to study the UV aging resistance of highly ductile concrete(HDC),the ultraviolet erosion test method was used to irradiate the HDC test block for 8 cycles in 30d cycles to study its erosion resistance.Through the uniaxial compression test of 34 groups of HDC and NC test blocks,the apparent characteristics of HDC after ultraviolet erosion at different ages were observed,and various basic mechanical indexes were obtained,including ultimate bearing capacity and peak strain.The test results show that after 240d ultraviolet irradiation,there is no obvious change on the surface of HDC and NC test blocks.However,the carbonization reaction speed inside concrete materials is accelerated,the calcium carbonate content increases,and the hydration reaction of concrete is weakened.The decrease rate of compressive strength of HDC and NC test blocks showed a trend of first increasing and then decreasing,and the reduction rate of compressive strength of HDC increased by 2.22%compared with NC.Ultraviolet erosion can lead to the fracture of fiber covalent bonds caused by damage to the outer layer of the fiber inside HDC,which belongs to fiber composites,and the impact on the macroscopic properties of HDC is reflected in the reduction of compressive strength and elastic modulus.
作者
寇佳亮
高如月
孙浩康
周恒
KOU Jialiang;GAO Ruyue;SUN Haokang;ZHOU Heng(School of Civil Engineering&Architecture,Xi'an University of Technology,Xi'an 710048,China;State Key Laboratory of Eco-hydraulics in Northwest Arid Region,Xi'an University of Technology,Xi'an 710048,China;Northwest Engineering Corporation Limited,Power China Xi'an 710065,China)
出处
《建筑结构》
北大核心
2023年第S02期1336-1341,共6页
Building Structure
基金
国家自然科学基金资助项目(52079109,51408487)。
关键词
高延性混凝土
紫外线老化
单轴受压
侵蚀机理
力学性能
high ductile concrete
ultraviolet radiation
uniaxial compression
erosion mechanism
mechanical properties
