全级配混凝土轴向拉伸应力-变形全曲线试验研究

Experimental study on the complete stress-deformation curve of full grade concrete under axial tension

混凝土受力破坏过程中的应力-变形全曲线能够宏观地反映混凝土在各个受力阶段的变形、内部微裂缝的发展、损伤积累、最终破坏等一系列过程,同时又是分析和计算混凝土构件承载力和变形的重要参数,因而备受研究者们的重视。但由于受试验条件的限制,国内外对混凝土轴向拉伸全曲线的研究,目前一般限于截面为25cm×25cm及以下尺寸,对大尺寸、全级配混凝土试件的轴向拉伸应力-变形全曲线的试验研究资料还很有限。本文利用自行研制的试验装置,以锦屏拱坝为背景,成功地进行了两组尺寸为450 mm×450 mm×1350mm的全级配混凝土轴向拉伸应力-变形全曲线的测试,根据试验结果拟合出混凝土轴拉应力-变形全曲线经验公式。有关成果可供大坝安全评价和设计部门参考。

The complete stress-deformation curve of destruction process of concrete reflects the overall behavior of concrete at various stages of deformation,internal micro cracks ’ development,damage accumulation until the final destroy,and a series of processes.It is also an important parameter used in analysis and calculation of the bearing capacity and deformation of concrete structures,so it attracts the researchers’great attention.The complete curve of axial tension concrete is generally restricted to the sample section of size not greater than 25cm × 25cm due to the limited test conditions,and experimental data of greater sample of full grade concrete are limited yet.By using our independently developed test equipments,we conducted an axial tension test on two groups of sample size 45cm × 45cm × 135cm and obtained by test data fitting an empirical formula of the complete curve of the full grade concrete that is adopted by the Jinping arch dam.The results would provide a reference for dam safety evaluation and dam design.