钢筋混凝土现浇楼板裂缝防治

钢筋混凝土现浇楼板裂缝的防治

摘要：钢筋混凝土现浇楼板裂缝是建筑施工中常见且较难克服的质量通病，这些裂缝大大降低了房屋结构的耐久性，破坏结构的整体性。楼板裂缝是由于设计、施工、环境外力等原因引起而产生裂缝，裂缝通常分为两大类：一是变形引起的裂缝，也称为非结构性裂缝，如温度变化，混凝土收缩、地基不均匀沉降等引起裂缝；二是由外荷载引起的裂缝，也称结构性裂缝或受力裂缝，其程度与荷载相应，预示结构承载力不足或存在严重问题。裂缝的表现形式为：现浇板易产生贯通性裂缝或上表面裂缝；现浇板外角部位易产生斜裂缝；现浇板沿预埋线管易产生裂缝。对现浇板裂缝，是否需要处理和怎样处理，主要取决于裂缝的性质及其危害性。对影响正常使用、降低耐久性的裂缝都应认真处理，除了正确选用处理方法和处理时间外，还应从消除原因着手。通过多年来现场监督检测工作的实践经验结论：要控制裂缝的出现，应从材料、设计、施工等多个方面入手进行综合防治。下面结合裂缝出现的部位阐述楼面裂缝的主要防治措施。

关键词：钢筋混泥土，裂缝 ， 防治

abstract: the cast-in-situ reinforced concrete floor cracks are common in building construction and more difficult to overcome the common faults, the cracks greatly reduces the houses of the durability of the structure, the whole of the destruction structure. floor cracks are due to design, the

construction, the environment caused by force, and cracks, the crack usually divided into two kinds: one is caused by deformation cracks, also known as the structural cracks, such as temperature change, shrinkage of concrete foundation, uneven subsidence caused by such as crack; 2 it is caused by the loading crack, also called the structural cracks or stress fracture, the degree and load the corresponding, signaling that the structure bearing capacity is insufficient or have serious problems. cracks in the form of: easy generation transfixion crack site casting integrated sex or to the surface crack; site casting integrated parts easy generation diagonal crack outside; along the embedded pipe line to site casting integrated cracks. to crack site casting integrated, whether to need to deal with and how to deal with, depending on the nature of the cracks and its harmfulness. to affect the normal use, reduce the endurance of the cracks are should handle, in addition to the correct choice of treatment methods and treatment time outside, still should eliminate reason to start. through many years site supervision and inspection work experience in the practice of conclusion: to control the cracks appear, from material, design, construction and so on many aspects for comprehensive prevention and control. cracks

appear below the parts with this the main floor cracks prevention and control measures.

keywords: reinforcing steel bar mixes clay, cracks, prevention and treatment

中图分类号：tu375文献标识码：a文章编号：

一、住宅的建筑平面宜规则，避免平面形状突变。当平面有凹口时，凹口周边楼板的配筋宜适当加强。当楼板平面形状不规则时，宜设置梁使之形成较规则的平面。在未设梁的板的边缘部位设置暗梁，提高该部位的配筋率，提高混凝土的抗裂性能。

二、应加大现浇板的刚度。现浇钢筋混凝土双向板设计厚度不应小于100mm,厨房、厕浴、阳台板不得小于80mm，当埋设线管较密或线管交叉时，板厚不宜小于120mm。对于过长的单向板，设计时应进行抗裂验算，合理确定加密分布筋的配置。

三、现浇板配筋设计宜采用热轧带肋钢筋细且密的配筋方案。 1、屋面及建筑物两端的现浇板及跨度大于4.2m的板应配制双层双向钢筋，钢筋间距不宜大于150mm，直径不应小于8mm。 2、外墙转角处应设置放射形钢筋，钢筋的数量、规格不应少于7￠10，长度应大于板跨的1∕3，且不得小于1.2m。

3、在现浇板的板宽急剧变化处、大开洞削弱处等易引导收缩应力集中处，钢筋间距不应大于150mm，直径不应小于8mm，并应在板的上表面布置纵横两个方向的温度收缩钢筋。板的上、下表面沿

纵横两个方向的配筋率均不应小于截面积的0.15%，且不小于￠6@200。

4、管线应尽量布置在梁内，当楼板内需埋置管线时，管线必须布置在上下钢筋网片之间，且不宜立体交叉穿越，确需立体交叉的不应超过两层管线。线管在敷设时交叉布线处可采用线盒，同时在多根线管的集散处宜采用放射形分布，尽量避免紧密平行排列，以确保线管底部的混凝土浇筑顺利且振捣密实。当两根以上管并行时，沿管方向应增加￠4@150宽500 mm的钢筋网片，做到在应力集中部位有双层布筋。

四、现浇板强度等级不宜大于c30,当大于c30时，应采取抗裂措施。