基于DIC的花岗岩-混凝土梁抗弯性能研究

Flexural Performance of Granite-Concrete Beams Based on DIC Technology

摘要:

为研究岩体缺陷对花岗岩-混凝土复合体抗弯性能的影响，选用2种花岗岩（黄金麻、芝麻灰）制备了不同缝高比（0、0.1、0.5）的花岗岩-混凝土试件，并进行了四点弯曲试验，采用三维数字图像相关（3D-DIC）技术对试件的裂缝开展过程进行了实时监测.结果表明：花岗岩弹性模量越大，试件承受荷载的能力就越强；当裂缝开展至胶结面时，由于花岗岩强度较高，试件荷载-应变曲线会再次上升，直至花岗岩开裂；预制裂缝的缝高比越大，同阶段试件的损伤程度越大，加载结束时裂缝宽度也越大，并且花岗岩弹性模量越大，试件损伤程度特征越明显；当花岗岩内部存在缺陷时，裂缝开展方向会向缺陷靠拢，导致试件进一步失稳破坏.

Abstract:

In order to study the influence of rock mass defects on the flexural properties of granite-concrete complex， two kinds of granite（gold flax and sesame ash） were selected to prepare specimens with different joint-height ratios（0， 0.1 and 0.5） for four-point bending tests. 3D digital image correlation（3D-DIC） was used to monitor the fracture propagation process of the complex. The results show that the larger the modulus of elasticity of granite is， the stronger the composite can withstand the load. When the crack develops to the cemented surface， the load curve will rise again due to the high strength of granite until the granite cracks. With the increase of the crack height ratio of prefabricated cracks， the damage degree of specimens at the same stage increases， and the crack width also increases at the end of loading. And with the increase of elastic modulus of granite， the characteristics of damage degree of specimen are more obvious. When there is a defect inside the granite， the crack development will be close to the granite defects， the specimen will further destabilize damage.