摘要
为探究试验方法对水工沥青混凝土抗拉特性量化的差异性,依据骨料级配理论配制不同级配指数的试样,采用单轴拉伸、劈裂与小梁弯曲3种试验进行抗拉特性测定;分析了强度、变形及临界应变能密度等指标,查明了沥青混凝土抗拉特性变化规律,揭示了3种试验结果差异性。试验结果分析表明,沥青混凝土应力应变曲线在单向拉伸时存在应变软化现象,受劈裂应力时呈双曲线性,受弯曲应力作用时应变软化程度受级配指数影响。与单轴拉伸试验结果相比,劈裂试验所测变形模量差异性较小,强度及峰值应变偏大10%、临界应变能密度偏大20%;小梁弯曲试验结果是单轴拉伸的1.3~2.8倍。宜首选单轴拉伸试验测定沥青混凝土抗拉特性参数,受限时可采用劈裂试验进行抗拉强度及变形模量测量。
In order to explore the quantitative difference of the test methods on the tensile properties of hydraulic asphalt concrete,this paper prepares samples with different gradation indexes according to the aggregate gradation theory,measures the tensile properties through uniaxial tensile test,splitting test and trabecular bending test,analyzes the indexes such as strength,deformation and critical strain energy density,identifies the changing law of tensile properties of asphalt concrete,and specifies the difference of the three test results.The test results shows that:The stress-strain curve of asphalt concrete shows strain softening when it is subjected to uniaxial tensile,and hyperbolic liner when it is subjected to splitting stress,and the strain softening is affected by the gradation index when it is subjected to bending stress.Compared with the uniaxial tensile test results,the difference in the deformation modulus measured by the splitting test is smaller,the strength and peak strain are 10%higher,and the critical strain energy density is 20%higher;the trabecular bending test results are 1.3~2.8 times that of uniaxial tensile test.The uniaxial tensile test is preferred to determine the tensile properties of asphalt concrete.When it is not available,the splitting test can be used to measure the tensile strength and deformation modulus.
作者
张扬
ZHANG Yang(Putian Ecological Water System Construction&Investment Management Co.,Ltd.,Putian 351106,China)
出处
《人民珠江》
2021年第8期79-84,共6页
Pearl River
关键词
抗拉特性
沥青混凝土
级配指数
应力应变特征
tensile properties
asphalt concrete
gradation index
stress-strain characteristics
