新旧混凝土界面粘贴机理试验研究

发布时间：2018-08-15 15:06

【摘要】：混凝土加固的粘结问题目前已广泛存在于既有混凝土结构补强、维修加固及新建混凝土工程中。混凝土结构现在存在非常多的问题:老化、钢筋锈蚀、预应力达不到原来的基本受力要求，疲劳破坏。现在运用增大截面法进行加固维修，成为一种主潮流，市场前景非常广阔。植筋技术也广泛运用在混凝土结构的加固维修中，无植筋技术素混凝土的计算方法，理论理念已相当成熟。但植筋后的混凝土结合面剪力的计算方法，在加载中，受力分析过程、受力机理、计算方法国内外研究的非常少。本文通过实验，收集实验数据，测出新旧混凝土结合面的剪力影响系数，详细论述了粘结机理，修正公式参数。首先，本文设计并制作了12组36个Z型构件，混凝土等级考虑了现在施工过程中最常用的C30/C40/C50三个等级的混凝土，配合比也是选用实际工程中最普遍的，钢筋选用Φ12的螺纹钢筋，实验考虑植入钢筋面积，钢筋的分布规律，混凝土的强度等级等可控因素对新旧混凝土结合面剪切强度的影响。其次，通过素混凝土Z形构件的实验数据，推导出了素混凝土纯剪切构件的结合面的剪切强度系数，并和以往推导的系数相互比较分析，从侧面证实了本次实验的可靠性、科学性，为下文粘结机理的提出，以及理论公式的推导提供科学依据。第三，根据本次实验，得到的实验数据，总结的实验规律，以增大截面法进行加固素混凝土的五区三粘基本理论模型的基础上，，提出了植入剪力筋后新旧混凝土结合面的五区三粘理论模型。第四，增大截面法进行加固，本文通过粘结机理，以实验现象为根据，清晰的论述了新旧混凝土植入钢筋后在加载过程中的整个破坏过程，并在不同受力阶段提出了剪切强度的计算公式，为以后加固维修计算分析提供了理论依据。
[Abstract]:At present, the bond problem of concrete reinforcement has been widely used in existing concrete structure reinforcement, maintenance and reinforcement and new concrete projects. There are many problems in concrete structure: aging, steel bar corrosion, prestress can not meet the original basic stress requirements, fatigue damage. Now it is a main trend to use the method of increasing section to reinforce and maintain, and the market prospect is very broad. Reinforcement technology is also widely used in the reinforcement and maintenance of concrete structures. The calculation method of plain concrete without planting tendons has been quite mature in theory. However, the calculation method of shear force of concrete joint surface after planting reinforcement is very few in the process of force analysis, stress mechanism and calculation method at home and abroad. In this paper, the influence coefficient of shear force on the new and old concrete bonding surface is measured by collecting the experimental data, and the bonding mechanism and the correction formula parameters are discussed in detail. First of all, this paper designs and makes 12 groups of 36 Z-type members. The concrete grade takes into account the three grades of C30/C40/C50, which are the most commonly used in the construction process. The mix ratio is also the most common in the actual engineering, and the reinforcement is made with the rebar of 桅 12. The effect of controllable factors, such as the area of reinforced bars, the distribution of steel bars and the strength grade of concrete, on the shear strength of new and old concrete joints is considered in the experiment. Secondly, based on the experimental data of plain concrete Z-shaped members, the shear strength coefficients of plain concrete pure shear members are derived, and compared with the previous ones, the reliability of this experiment is confirmed. It provides scientific basis for the mechanism of bond and the derivation of theoretical formula. Thirdly, according to the experimental data and the experimental rules, the basic theory model of strengthening plain concrete with five zones and three viscosities is carried out by the method of increasing section. This paper presents a five-zone three-viscosity model for the new and old concrete joints after the shear tendons are implanted. Fourthly, the method of increasing section is used to reinforce the concrete. Based on the mechanism of bond and the experimental phenomenon, the whole failure process of new and old concrete is clearly discussed in the course of loading. The formula of shear strength is put forward in different stress stages, which provides a theoretical basis for the calculation and analysis of reinforcement and maintenance in the future.
【学位授予单位】：长安大学
【学位级别】：硕士
【学位授予年份】：2014
【分类号】：U445.72;U445.57

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