现浇楼板裂缝质量控制

摘要

混凝土裂缝历来被视为混凝土工程中的一大顽疾。由于混凝土裂缝会使建筑结构功能受到不同程度的削弱，而混凝土结构的破坏也常常是从裂缝幵始的，因此人们把裂缝视作危险的征兆，更有甚者产生“裂缝恐惧感”。根据近代关于混凝土材料的科学研究和大量工程实践可知，几乎所有的混凝土结构都是带有裂缝的，而这些裂缝随时都在不断的发育和变化，因此我们可以说裂缝的存在既是混凝土材料自身的一个缺陷，又是混凝土自身的一个固有属性。虽然混凝土裂缝是不可避免的，但其危害程度却是可以控制的，而关键问题在于我们必须针对裂缝问题的实质采取一系列行之有效的设计和施工等方面的措施，减少引起混凝土“微观裂缝”扩展的不利因素的影响，来达到控制裂缝的目的。

随着国家城市化进程的不断加快、土地资源的紧缺、建筑业的发展，楼房越建越高，钢筋混凝土结构普遍使用及商品混凝土的推广，建筑物楼面出现裂缝的机率不断增加，已成为当前商品房质量纠纷、投诉的热点问题。它不仅影响使用功能，有损外观，而且较大的裂缝会破坏结构的整体，降低其刚度，引起钢筋锈蚀，影响结构耐久性。针对现浇混凝土楼板裂缝，本文进行了以下几个方向的工作：

1、从概念上分析现浇混凝土楼板结构裂缝的类型、主要特征、形成机理以及发育过程。

2、从设计和施工两个方面对现浇混凝土楼板裂缝的产生因素进行分析，并提出相应的控制措施，结合工程实例对如何控制现浇混凝土楼板裂缝进行讨论。

3、为了更好的防止裂缝的产生，提出裂缝的综合控制方法，即综合考虑各方面原因，从多道工序上采取相应措施，对设计及施工具有一定的指导意义。

关键词　钢筋混凝土 楼板裂缝 原因 综合控制

abstract

The concrete crack has been regarded as a major problem in concrete engineering. Due to cracks in the concrete building structure and function has been weakened in different degree, and the destruction of concrete structures is often the beginning of from the cracks and, so people have cracks are regarded as the sign of danger, even produce "crack fear". According to the modern scientific research in on concrete materials and a large number of engineering practice shows that, almost all of the concrete structure is a crack, and these cracks at any time in the continuous development and change, so we can crack said there is the concrete material itself of a defect, and is an intrinsic property of concrete itself. Although the concrete crack is inevitable, but the extent of damage is to control, and key problem is we have to crack the essence of take a series of effective design and construction measures, caused a decrease in the effect of concrete micro crack propagation of unfavorable factors, to achieve the purpose of crack control.

With the urbanization process accelerating, land resources shortage, the architecture industry development. The building is built higher, reinforced concrete structure commonly used goods and concrete, building floor appeared increasing the probability of crack, has become the hot issues in the current commercial housing quality disputes, complaints. It not only affects the use of function, damage to the appearance, but also the larger cracks will damage the overall structure, reduce its stiffness, cause steel corrosion, affecting the durability of the structure. In view of the cracks in the cast in place concrete floor, this paper has carried on the following several directions of work:

The paper analyzes the types, main characteristics, formation mechanism and development process of the cracks in cast in place concrete floor.

From the two aspects of design and construction of the concrete floor cracks in the analysis of the factors, and put forward the corresponding control measures, combined with the engineering examples on how to control the cast in place concrete floor cracks are discussed.

In order to prevent the crack from producing, put forward the comprehensive control method of the crack, that is to consider all aspects of the reasons, from the multi-channel process to take the corresponding measures, the design and construction has certain guiding significance.

Key words reinforced concrete floor crack reason comprehensive control

目录

摘要 I

目录 I

第1章 绪论 2

1.1 国内外混凝土结构裂缝研究现状 2

1.2 本文的主要研究内容 2

第2章 钢筋混凝土裂缝理论分析 3

2.1 混凝土裂缝的基本概念 3

2.2混凝土裂缝产生的主要原因 3

2.3现淺混凝土楼板裂缝产生的机理 4

第3章 裂缝控制的方法 6

3.1 设计因素导致的裂缝原因及其控制措施 6

3.1.1 设计因素导致裂缝的原因分析 6

3.1.2 设计因素产生的裂缝的预防控制措施 6

3.2 施工因素导致的裂缝原因及其控制措施 7

3.2.1 不合理的施工荷载 7

3.2.2 楼板上层钢筋挪移 8

3.2.3 预埋管线的影响 8

3.2.4 后淺带的施工不慎 9

3.2.5 过分的抹平压光和养护不当 9

3.2.6 拆模过早和支撑体系刚度不足 10

第4章 结论与展望 11

4.1 结论 11

4.2 展望 11

参考文献 12

致谢 13