骨料组分和强度等级对混凝土单轴受压性能尺寸效应的影响

发布时间：2018-12-30 15:48

【摘要】：为研究骨料组分和强度等级对混凝土单轴受压时受力和变形性能尺寸效应的影响,制作了135组混凝土、水泥砂浆和水泥净浆棱柱体试件。试件混凝土强度等级为C20、C40和C60,尺寸为100 mm×100 mm×200 mm,150 mm×150 mm×300 mm和200 mm×200 mm×400 mm。采用刚性辅助架法获得了单轴受压应力-应变全曲线,分析了轴心抗压强度、峰值应变以及弹性模量的尺寸效应。结果表明:混凝土、水泥砂浆及水泥净浆试件的轴心抗压强度和峰值应变均存在尺寸效应现象,而混凝土的弹性模量无明显的尺寸效应;强度等级对混凝土轴心抗压强度和峰值应变的尺寸效应的影响较大,截面边长200 mm的C60混凝土试件的轴心抗压强度与峰值应变的尺寸效应度分别约为C20混凝土的2倍与1.6倍;骨料组分对尺寸效应有明显影响,截面边长200 mm混凝土试件的轴心抗压强度和峰值应变的尺寸效应度分别约为水泥砂浆的2.3倍和3倍,细骨料对尺寸效应的影响较弱,水泥净浆轴心抗压强度和峰值应变的尺寸效应度分别约为水泥砂浆的75%和65%。根据试验结果,提出了混凝土、水泥砂浆和水泥净浆轴心抗压强度与峰值应变尺寸效应律计算式,其计算结果与试验结果吻合良好。
[Abstract]:In order to study the effect of aggregate composition and strength grade on the size effect of concrete under uniaxial compression, 135 groups of concrete, cement mortar and cement mortar prism were made. The strength grades of the specimens are C20C40 and C60, and the sizes are 100 mm 脳 100 mm 脳 200 mm,150 mm 脳 150 mm 脳 300 mm and 200 mm 脳 200 mm 脳 400 mm.. The full stress-strain curves under uniaxial compression are obtained by means of rigid auxiliary frame method. The size effects of axial compressive strength, peak strain and elastic modulus are analyzed. The results show that the axial compressive strength and peak strain of concrete, cement mortar and cement paste have size effect, but the elastic modulus of concrete has no size effect. The strength grade has a great influence on the size effect of axial compressive strength and peak strain of concrete. The axial compressive strength and the size effect of peak strain of C60 concrete specimen with side length of 200 mm are about 2 times and 1.6 times of that of C20 concrete, respectively. The axial compressive strength and the size effect of peak strain of 200 mm concrete specimen are about 2.3 times and 3 times of that of cement mortar, respectively, and the influence of fine aggregate on size effect is weak. The size effect of axial compressive strength and peak strain of cement paste is about 75% and 65% of cement mortar respectively. Based on the experimental results, a formula for calculating the axial compressive strength and peak strain size effect law of concrete, cement mortar and cement paste is proposed. The calculated results are in good agreement with the experimental results.
【作者单位】：湖南大学土木工程学院;
【基金】：国家自然科学基金项目(51278182) 湖南省科技计划项目(2013CK4014) 湖南大学青年教师成长计划项目(531107040742) 广西科学与技术开发计划项目(桂科攻1355008-9)
【分类号】：TU528.0;TU37

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