Fibre Reinforcement for Shrinkage Crack Control in Prestressed, Precast Segmental Bridges
Fibre Reinforcement for Shrinkage Crack Control in Prestressed, Precast Segmental Bridges
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用于预应力预制节段桥梁收缩裂缝控制的纤维增强
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发表时间：
2010
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通讯作者：
J. Susetyo
中科院分区：
文献类型：
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作者：
J. Susetyo
在预应力预制节段混凝土桥梁中，传统的纵向钢筋只能起到控制收缩裂缝的作用。然而，当使用高强度混凝土时，这种钢筋的存在限制了减少分段横截面的能力，因为容纳钢筋所需的最小尺寸。对纤维增强混凝土（FRC）的研究表明，在混凝土中加入钢纤维可显著改善混凝土的抗拉性能和裂缝控制特性。本研究调查了纤维替代传统收缩钢筋的可行性，允许设计更薄更轻的结构，具有类似或更好的裂缝控制特性。开展了大量的工作来研究钩端钢纤维控制裂缝的有效性。进行了7类材料试验：单轴拉伸试验、圆柱体压缩试验、断裂模量试验、劈裂试验、自由和自收缩试验、约束收缩试验。此外，利用面板单元测试仪对10块890×890×70 mm混凝土面板进行了面内纯剪加载试验。研究参数为纤维体积含量（0.5%、1.0%和1.5%）、混凝土抗压强度（50和80 MPa）、纤维几何形状和抗拉强度。除了实验研究之外，还开发了一个模型来研究受收缩约束的一维FRC构件的行为。
In prestressed precast segmental concrete bridges, conventional longitudinal reinforcement serves only as shrinkage crack controllers. The presence of this reinforcement, however, has restricted the ability to reduce the cross-section of the segments when high strength concrete is used because of the minimum dimensions required to accomodate the reinforcement. Research on fibre reinforced concrete (FRC) indicated that the addition of steel fibres to concrete significantly improved the tensile behaviour and the crack control characteristics of the concrete. This research investigates the feasibility of fibres to replace the conventional shrinkage reinforcement, allowing for the design of thinner and lighter structures with comparable or better crack control characteristics. Extensive work was conducted to investigate the effectiveness of hooked-end steel fibres to control cracks. Seven types of material tests were performed: uniaxial tension test, cylinder compression test, modulus of rupture test, splitting test, free and autogenous shrinkage test, and restrained shrinkage test. In addition, ten 890×890×70 mm concrete panels were tested under in-plane pure-shear loading using the Panel Element Tester. The parameters of study were the fibre volume content (0.5%, 1.0%, and 1.5%), the concrete compressive strength (50 and 80 MPa), and the fibre geometry and tensile strength. In addition to the experimental study, a model was developed to investigate the behaviour of a 1D restrained FRC member subjected to shrinkage.