硅粉及纤维改性再生混凝土柱抗震性能试验研究

发布时间：2018-05-24 13:41

本文选题：硅粉 + 复合纤维　；参考：《西安建筑科技大学》2013年硕士论文

【摘要】：再生混凝土技术不仅能够缓解日益严峻的资源短缺问题，而且还可以很好地解决废弃混凝土带来的环境污染问题，对节约能源、资源、减轻环境压力及维持生态平衡都有十分重要的意义。但再生骨料在强度及密实度等方面都存在一些缺陷，用其制备的再生混凝土与普通混凝土也有一定差异。因此，为了扩大再生混凝土的应用范围，加快其在实际工程中的应用，有必要研究再生混凝土的改性方法以及改性再生混凝土构件的抗震性能。本文将课题组收集的废弃混凝土制备成再生骨料，利用硅粉的填充及纤维的阻裂、增强、增韧作用，设计并制作了不同硅粉和纤维掺量的改性再生混凝土试块并进行了相应的试验研究，接着以此为基础，制作了5根改性再生混凝土和1根普通混凝土框架柱，通过伪静力加载试验，研究了硅粉及纤维改性再生混凝土柱的抗震性能。主要工作及研究内容如下：（1）以不同掺量硅粉和两种聚丙烯纤维为主要参数，设计制作了30组共90个混凝土试块，分别为单掺硅粉、复掺硅粉和纤维等。通过试验，研究了硅粉及纤维改性再生混凝土试块的立方体抗压强度、轴心抗压强度、劈裂抗拉强度、抗折强度、弹性模量及峰值应变等，分析了硅粉及纤维对再生混凝土材料力学性能的影响，同时还研究了硅粉及纤维掺量变化时混凝土受压的应力-应变曲线，给出了改性再生混凝土本构模型的上升段方程。（2）以某实际工程为原型，按1/2缩尺比例设计框架柱试验模型，进行低周反复荷载作用下的伪静力试验，研究了再生粗骨料取代率为30%时，不同掺量硅粉和纤维再生混凝土框架柱的破坏模式、滞回性能、承载能力、延性、刚度和耗能能力等，并以试验结果为依据，分析了各性能指标随硅粉和纤维掺量变化的一般规律，，得出了一些可供参考的结论和建议。（3）以文中建议本构模型为基础，结合已有研究结果，采用MATLAB软件对改性再生混凝土应力-应变曲线主要参数进行了改进，并以此为依据进行了各框架柱极限承载能力的计算，同时与《混凝土结构设计规范》（GB50010-2010）的计算结果和试验结果进行了对比分析，得出了较为准确的硅粉及纤维改性再生混凝土柱承载能力的主要计算参数。（4）采用文中建议的硅粉及纤维改性再生混凝土的本构关系和参数设置，利用ANSYS有限元分析软件，对上述试验模型柱进行了数值模拟分析，得出了各试验模型柱裂缝分布及走向、P滞回曲线及骨架曲线等，并与试验结果进行了对比，两者吻合较好，说明文中建议的本构模型比较合理，可用于相应构件的非线性有限元分析。研究结果表明，掺入硅粉能够提高再生混凝土的立方体抗压强度，但峰值应变相对普通再生混凝土有所下降；掺加纤维对其劈裂抗拉强度、抗折强度及峰值应变等都有不同程度的提高，增幅大小相对不一致；硅粉及纤维混合掺入能够改善再生混凝土的力学性能，但峰值应变均较普通混凝土的低。理论分析和试验研究结果均表明，硅粉及纤维改性再生混凝土柱的破坏模式与普通混凝土柱的相似；掺入适量硅粉能够提高再生混凝土柱的承载能力和变形能力，但初始刚度有所降低，后期抗震性能衰减速率也随掺量增加而加快；纤维的适量掺入可明显提高硅粉改性再生混凝土柱的刚度、承载能力、变形和耗能能力等，是一种再生混凝土材料性能提高的有效途径。
[Abstract]:In order to expand the application scope of recycled concrete and accelerate its application in practical engineering , it is necessary to study the modification method of recycled concrete and the aseismatic performance of modified recycled concrete .

In this paper , the waste concrete collected by the research group is made into recycled aggregate , and the filling of silicon powder and the resistance to crack , reinforcement and toughening of silicon powder are used to design and fabricate the modified recycled concrete test blocks with different silicon powder and fiber content . Then , five modified recycled concrete and one common concrete frame column are prepared . The anti - seismic performance of silicon powder and fiber - modified recycled concrete columns is studied by the pseudo - static loading test .

( 1 ) The compressive strength , axial compressive strength , splitting tensile strength , flexural strength , elastic modulus and peak strain of silicon powder and fiber modified recycled concrete specimen were studied by using different amount of silicon powder and two kinds of polypropylene fibers as main parameters . The influence of silicon powder and fiber on the mechanical properties of recycled concrete was studied .

( 2 ) Based on the experimental results , the failure mode , hysteretic behavior , bearing capacity , ductility , rigidity and energy dissipation capacity of the concrete frame column with different content of silicon powder and fiber were studied by designing the frame column test model according to the scale of 1 / 2 scale . The general rule of each performance index with the change of silicon powder and fiber content was analyzed based on the experimental results , and some conclusions and suggestions were obtained .

( 3 ) Based on the proposed constitutive model , the main parameters of the modified recycled concrete stress - strain curve are improved by using MATLAB software , and the calculation of ultimate bearing capacity of each frame column is carried out .

( 4 ) By using the constitutive relation and parameter settings of silicon powder and fiber modified recycled concrete as suggested in the paper , using ANSYS finite element analysis software , the numerical simulation analysis of the test model column is carried out , and the crack distribution and trend , P hysteresis curve and skeleton curve of each test model column are obtained . The results are in good agreement with the test results . The proposed constitutive model is reasonable and can be used for nonlinear finite element analysis of the corresponding components .

The results show that the compressive strength of recycled concrete can be improved by incorporating silicon powder , but the peak strain is lower than that of ordinary recycled concrete .
The tensile strength , flexural strength and peak strain of the doped fiber were improved to some extent , and the magnitude of the increase was relatively inconsistent .
The mixing of silicon powder and fiber can improve the mechanical properties of recycled concrete , but the peak strain is lower than that of ordinary concrete .

Theoretical analysis and experimental results show that the failure mode of silica powder and fiber - modified recycled concrete column is similar to that of ordinary concrete column ;
Adding proper amount of silicon powder can improve the bearing capacity and deformation capacity of the recycled concrete column , but the initial stiffness decreases , and the attenuation rate of the later anti - seismic performance increases with the increase of the mixing amount .
The proper amount of fiber can obviously increase the rigidity , bearing capacity , deformation and energy consumption of the regenerated concrete column , which is an effective way to improve the performance of recycled concrete material .
【学位授予单位】：西安建筑科技大学
【学位级别】：硕士
【学位授予年份】：2013
【分类号】：TU375.3;TU352.11

【参考文献】