配筋对混凝土构件收缩和徐变的影响研究

The Effect of Reinforcement to Shrinkage and Creep of Concrete Component

本文制作了4根同强度混凝土梁,在改变其配筋率的情况下分别测量4根梁150d内梁端中心处的收缩变化值;结合试验数据与理论推导发现加筋构件的收缩与配筋率、构件尺寸等多种因素有关,钢筋对混凝土构件收缩的约束度会随配筋率的提高而提高,而单位钢筋面积的约束度会随配筋率的增大而降低;混凝土加筋构件的收缩需考虑徐变作用,本文将试验数据代入计算公式得到了各组混凝土梁的徐变系数;与通过国外相关规范计算得到的徐变系数进行对比,发现在拉力作用下加筋构件的徐变系数除受拉力与混凝土的力学性质控制外,还可能与混凝土内的湿度梯度分布及微裂缝的产生有关。

Article made four concrete beam with same strength,in the case of changing its reinforcement ratio to measure the ends of center shrinkage within 150 days,combining experimental data and theoretical derivation was found that reinforcement ratio,size of components,and other factorsall can effect reinforced concert component’s shrinkage,the constraint degree of concrete component will be improved with the increase of reinforcement ratio,but the constraint degree of unit reinforced area will reduce along with the increase of reinforcement ratio;shrinkage of reinforced concrete component should be considered creep’s effect.This article obtained creep coefficient of each group’s concrete beam through plug test data into the formula,compared with the creep coefficient calculated by foreign related specification founded:Under tension,the creep coefficient of reinforced components be controlled except by the tensile force and the mechanical properties of concrete,may also related with moisture gradient distribution and micro cracks in concrete.