摘要
为研究水工沥青混凝土动态力学性能,对水工沥青混凝土在不同温度条件下进行了动态抗压试验。试验结果表明:水工沥青混凝土的破坏模式具有显著的应变率效应,应变速率为10^-5/s和10^-4/s时,破坏模式主要为黏结破坏;应变速率为10^-3/s和10^-2/s时,破坏模式主要为黏结破坏和骨料开裂。温度对试件应力应变特性有显著影响,当应变速率不小于10^-4/s时,-5℃和0℃时试件呈现应变软化现象;5℃时应变软化逐渐向应变硬化转变。当温度恒定时,水工沥青混凝土的吸能能力、弹性模量、抗压强度随应变速率增加而增加。对弹性模量和抗压强度的动态增强因子进行分析,给出了水工沥青混凝土在不同温度条件下弹性模量动态增强因子随应变速率变化的经验公式,非线性单轴动态强度S准则较好地反映了水工沥青混凝土在地震响应速率下动态抗压强度的增长特性。
Dynamic compression tests on hydraulic asphalt concrete are carried out to study the dynamic mechanical properties under different temperatures. The test results show a strong dependence of the concrete failure mode on strain rate. At strain rates of 10^-5/s and 10^-4/s, the specimen mainly takes the mode of bond failure, while at strain rates of 10^-3/s and 10^-2/s, it takes bond failure and aggregate cracking. Temperature has a significant effect on the stress-strain characteristics of specimens. When the strain rate is ≥ 10^-4/s, strain softening occurs at-5℃ and 0℃;strain hardening gradually develops from the threshold of 5℃.At a constant temperature of the concrete, its energy absorption capacity, elastic modulus, and compressive strength are all increased with the increase in strain rate. We analyze the dynamic increase factors(DIFs) of elastic modulus and compressive strength, and suggest an empirical formula for calculating the DIFs of elastic modulus for different strain rates at different temperatures. It is found that the S criterion of nonlinear uniaxial dynamic strength is a good parameter of hydraulic asphalt concrete reflecting the characteristics of growth in its dynamic compressive strength at different seismic response rates.
作者
宁致远
刘云贺
薛星
NING Zhiyuan;LIU Yunhe;XUE Xing(State Key Laboratory of Eco-hydraulic Engineering in Northwest Arid Region, Xi'an 710048;School of Civil Engineering and Architecture, Xi'an University of Technology, Xi'an 710048;School of Water Resources and Hydro-electric Engineering, Xi'an University of Technology, Xi'an 710048)
出处
《水力发电学报》
EI
CSCD
北大核心
2019年第10期24-34,共11页
Journal of Hydroelectric Engineering
基金
国家自然科学基金(51779208)
水利部公益性行业科研专项(201501034-03)
关键词
水工沥青混凝土
动力特性
破坏模式
应变速率
吸能能力
hydraulic asphalt concrete
dynamic mechanical property
failure mode
strain rate
energy absorption capacity
