STRENGTH AND DUCTILITY OF CONFINED CONCRETE
STRENGTH AND DUCTILITY OF CONFINED CONCRETE
复制标题
DOI：
10.1061/(asce)0733-9445(1992)118:6(1590
复制
发表时间：
1992-06-01
期刊：
影响因子：
--
通讯作者：
RAZVI, SR
中科院分区：
文献类型：
--
作者：
SAATCIOGLU, M;RAZVI, SR
提出了一种建立约束混凝土应力应变关系的解析模型。该模型由一个抛物线上升分支和一个线性下降段组成。它基于圆形和直线钢筋产生的侧向约束压力的计算，以及由此产生的约束混凝土强度和延性的改善。评估了大量的试验数据，包括约束不良和约束良好的混凝土，以建立分析模型的参数。约束混凝土强度和相应的应变用钢筋笼提供的等效均匀围压来表示。根据截面特性和材料特性计算的平均侧向压力可得到等效均布压力。不同类型侧向配筋的组合约束是通过叠加单个约束效应来评估的，下降分支是通过定义对应于峰值应力85%的应变来构造的。这个应变水平用约束参数来表示。假定下降分支以上的剩余强度为恒定的，强度水平为20%。将该模型与大量的柱试验进行了比较。圆柱体、方柱体、矩形柱体、螺旋钢筋和直线钢筋，以及焊接钢丝网用于比较。比较包括同心和偏心加载，以及慢应变和快应变速率。结果表明，该方法具有较好的一致性。
An analytical model is proposed to construct a stress-strain relationship for confined concrete. The model consists of a parabolic ascending branch, followed by a linear descending segment. It is based on calculation of lateral confinement pressure generated by circular and rectilinear reinforcement, and the resulting improvements in strength and ductility of confined concrete. A large volume of test data, including poorly confined and well-confined concrete was evaluated to establish the parameters of the analytical model. Confined concrete strength and corresponding strain are expressed in terms of equivalent uniform confinement pressure provided by the reinforcement cage. The equivalent uniform pressure is obtained from average lateral pressure computed from sectional and material properties. Confinement by a combination of different types of lateral reinforcement is evaluated through superposition of individual confinement effects, The descending branch is constructed by defining the strain corresponding to 85% of the peak stress. This strain level is expressed in terms of confinement parameters. A constant residual strength is assumed beyond the descending branch, at 20% strength level. The model is compared against a large number of column tests. Circular, square, and rectangular columns, with spiral and rectilinear reinforcements, as well as welded wire fabric, are used for comparison. Comparisons include concentric and eccentric loadings, as well as slow and fast strain rates. The results indicate good agreement.