【作者】 刘炜；

【导师】 黄政宇；

【作者基本信息】 湖南大学 ， 结构工程， 2013， 硕士

【摘要】 活性粉末混凝土(Reactive Powder Concrete，简称RPC)是一种新型的水泥基复合材料，其抗压强度、抗拉强度、抗折强度、韧性及耐久性等在物理与力学方面的性能远优于普通混凝土，因此，国内外很多学者都对这种新型材料产生了浓厚的兴趣，并积极将这种材料推广到工程应用中，使其在工程领域具有广阔的应用前景。但是在工程上大多数结构都是以配筋的形式出现，而且RPC的抗拉性能又影响着结构的使用年限，所以研究配筋RPC的抗拉性能具有很现实的意义。为此，本文选取纤维含量和配筋率作为变化因素考察无筋RPC和配筋RPC的抗拉性能，并得出了如下结论：(1)对无筋RPC及配筋RPC试件进行轴拉试验，通过试验结果可以知道：对于无筋RPC轴拉试件，当不掺入钢纤维时，其破坏形式为脆性破坏，并且由于试验机的刚度不足而不能测出应力-应变曲线的下降段，而随着纤维含量的增加，其破坏形式由脆性破坏转变为韧性破坏；对于配筋RPC轴拉试件，其破坏形式呈现多缝开裂；(2)根据无筋RPC轴拉试件的应力-应变曲线可以知道，掺有钢纤维的无筋轴拉试件破坏过程大致分为三个阶段：近似线性增长阶段、应力硬化阶段和下降段；无论配筋率为多少，配筋RPC的轴拉应力-应变曲线破坏过程大致可以分为三个阶段：近似弹性阶段、弹塑性阶段和轴力稳定阶段；(3)对配筋RPC试件进行了裂后分析，指出了RPC约束收缩的影响，并且提出了收缩修正模型。基于此模型，我们对配筋RPC试件轴拉应力-应变曲线进行了修正。通过分析知道，钢筋主要影响曲线的下降段，对曲线的上升段基本无影响；(4)通过试验结果分析，本次试验建立了三折线式的配筋RPC轴拉试件的本构模型，并进行了参数拟合，拟合曲线与平均曲线吻合较好。更多还原

【Abstract】 Reactive Powder Concrete(RPC) is a new type of cement-based composite material,Its physical and mechanical performance such as compressive strength、 tensile strength、bending strength、ductility and durability is much better than common concrete, therefore, many scholars at home and abroad are very interested in the new type of material, and actively to promote the material to the engineering application, and make it having wide application prospect in the engineering field. The most structures in the engineering appearance within steel bar, and the tensile performance of RPC affects the service life of structures, so research on the reinforced RPC has realistic significance. Therefore, this dissertation selects fiber content and reinforcement ratio as parameters, and research the tensile performance of RPC and reinforced RPC, the conclusions are summarized as follows:(1)Through the results of uniaxial tensile testing of RPC and reinforced RPC:for RPC uniaxial tensile specimens, when adding no steel fiber, there destruction forms are brittle failure, and it is failure to detect the descending part of stress-strain curve due to the insufficient stiffness of machine, with the increase of fiber content, the destruction form of RPC change from brittleness to ductility;for reinforced RPC uniaxial tensile specimens, their destruction forms are multiple-slit failure;(2)According to the tensile stress-strain curves of the RPC specimens, the failure process of tensile specimens can be divided into three phases:the approximate linear growth stage, the stress hardening stage and decline stage;the failure process of reinforced tensile specimens can be divided into three stages:approximate elastic stage, elastic-plastic stage and the axial force stable stage;(3)Through analysis of reinforced RPC when after cracking, we know that the restrained shrinkage have significant influence on the tensile performance, so we put forward the restrained shrinkage model of reinforced RPC. Based on the model, we amend all the stress-strain curves of reinforced RPC specimens. Based on the analysis, the steel bar mainly affect the descending segment of stress-strain curves, but little impact on the rising part of curves;(4)According to the results, the test set up a theoretical trilinear constitutive model of reinforced RPC tensile stress-strain curve, and fitting curves are in good agreement with average curves after parameter fitting.更多还原