宁波车牌识别系统匠心厂

混凝土小型空心砌块裂缝产生的原因分以下三点：

The causes of cracks in small concrete hollow blocks are divided into three points:

1、 材料本身的原因

1, the cause of the material itself

（1）混凝土砌块的质量：混凝土的收缩与所使用的材料、配合比、生产环境、养护环境、龄期、外加剂以及构件的形状的尺寸等有关。其中，龄期的影响最大，龄期越长，收缩变形越缓慢。实践证明，在龄期一个月时，其收缩变形可完成最终收缩变形的50%～60%，因此，规范明确规定“施工时所用的小砌块的产品龄期不应小于28d”。由于目前建设规模大，工期短，任务急，对砌块的需求量大，而砌块生产企业规模相对较小，管理不够健全，这就导致不足龄期的砌块即出厂使用到工程上。这些不足龄期的砌块砌筑的墙体会发生很大的干缩变形，即在相同温差条件下，混凝土空心砌块的变形要比粘土砖大两倍。再之，由于砌块的龄期短，强度低，在装卸和运输过程中很容易导致砌块缺棱角、裂缝甚至断裂，从而给砌体结构留下质量隐患，导致裂缝的产生。配合比对砌块的质量也有相当的影响，尤其对砌块的强度越低和收缩变形影响较大，水灰比越大，砌块的强度越低，收缩变形越大，砌体受温度变化的变形也就越大，墙体就越容易开裂。

(1) the quality of concrete block: the shrinkage of concrete is related to the material used, the mix ratio, the production environment, the maintenance environment, the age, the admixture and the size of the shape of the components. Among them, the influence of age is the biggest, and the longer the age, the slower the shrinkage deformation. It is proved by practice that the shrinkage deformation can complete 50% to 60% of the final contraction deformation at one month of age. Therefore, the specification clearly stipulates that the age of the small block used for construction should not be less than 28d. As the construction scale is large, the time limit is short, the task is urgent, the demand for the block is large, but the size of the block production enterprise is relatively small and the management is not perfect. This leads to the use of the block that is less than the age of the age. The wall of these insufficiently aged block masonry will be greatly deformed, that is, under the same temperature difference, the deformation of concrete hollow block is two times larger than that of clay brick. In addition, because the age of the block is short and the strength is low, it is easy to cause the block angle, crack and even fracture in the process of loading and unloading and transportation, which will leave the hidden quality of the masonry structure and cause the crack. It has a considerable influence on the quality of the block, especially the lower the strength of the block and the shrinkage deformation, the greater the water cement ratio, the lower the strength of the block, the greater the shrinkage deformation, the greater the deformation of the masonry, and the more easy the wall is to crack.

（2）砌筑砂浆的质量：砌筑一面合格的墙体需要有合格的砌筑砂浆，砂浆的标号、和易性都会对墙体的质量产生较大的影响，标号低、和易性差的砂浆将会降低墙体的整体性能，削弱墙体的抗剪、拉和变形的能力，从而产生裂缝。混凝土空心砌块填充墙的砌筑砂浆强度等级一般为M5.

(2) the quality of masonry mortar: building a qualified wall masonry needs to have qualified masonry mortar. The mark and ease of the mortar will have a great influence on the quality of the wall. The low marking and poor workability of mortar will reduce the overall performance of the wall and weaken the shear, pull and deformation capacity of the wall, thereby cracking the wall. Sew. The strength grade of masonry mortar for concrete hollow block infill walls is generally M5.

2、施工方面的原因工程技术员认为由于施工操作不当而导致的裂缝是墙面开裂的主要原因之一。

2, construction reasons. Engineering technicians believe that cracks caused by improper construction operations are one of the main reasons for wall cracking.

（1）砌筑砂浆不饱满、不密实、通缝、瞎缝，是导致墙体裂缝的重要诱因。

(1) masonry mortar is not full, not dense, through joints and blind joints, which is an important inducement for wall cracks.

（2）忽视构造要求，未能按照规定采取抗裂措施。

(2) ignoring structural requirements, failing to take crack resistance measures in accordance with regulations.

设计人员在设计的时候总会采取一些构造措施，以避免裂缝的产生。比如，在墙体与混凝土柱之间设置拉结钢筋，在墙体与柱、梁交接处设置钢丝网片。由于施工管理不到位，加之工人的马虎施工，或者不按规定施工，应该按照规定设置的拉结钢筋和钢丝网片有的没有设置，有的虽然设置了，却没有按规定的间距或长度设置，有的间距和长度都按规定设置了，但没有设置弯钩，也有的一切都按规定设置了，但拉结钢筋与柱和墙体的锚固不牢，从而失去了锚固的作用等等。

Designers will always take some structural measures during design to avoid cracks. For example, a rake bar is set between the wall and the concrete column, and a steel wire mesh is arranged at the junction of the wall and the column and beam. Because the construction management is not in place, in addition to the worker's careless construction, or not according to the prescribed construction, it should be set up in accordance with the provisions of the steel bar and steel wire mesh, some have not been set up, but have not been set according to the prescribed distance or length, some spacing and length are set according to the regulations, but no bending hook is set. All of them are set up according to the regulations, but the anchorage of Raji steel bars and columns and walls is not strong enough to lose anchorage.

（3）规范规定每次墙体砌筑高度不应超过1.8m.实际操作中，施工单位为了抢工期，片面地追求利益的最大化，往往是不论墙体有多高，总是一次砌到顶部（包括封口），导致墙体变形。

(3) the standard stipulates that each wall masonry height should not exceed the actual operation of 1.8m.. In order to maximize the profit, the construction unit is always pursuing the maximum of interest for a one-sided period. It is always a wall, no matter how high the wall is, always at the top (including the seal), resulting in the deformation of the wall.

（4）由于管理上的不严谨，工种交叉施工时马虎，后道工序对已完成的成品墙体肆意践踏而导致裂缝。比如：立模时不能很好地保护墙体，而使已经成型的墙体松动或移位；水电管不是随墙体同时埋设，而是在墙体成型后随意打砸，墙体破坏严重。

(4) due to the lack of rigor in management, construction work is sloppy when construction works are crossed, and subsequent processes cause cracks on finished finished walls. For example: the model can not protect the wall well, and make the formed wall loose or displaced; the hydroelectric pipe is not buried with the wall at the same time, but at random after the wall is formed, the wall is destroyed seriously.

3、地基原因所有的建筑都离不开厚实的地基，但是，自然生成的地基，在构造上总会有所差异，承载力总会有所不同，压缩量会有差异，导致房屋的沉降不均匀，从而出现裂缝。这种裂缝往往多出现在墙面的斜裂和门窗洞口四角的斜裂缝，多表现为“八”字形和倒“八”字形。

3, the foundation of all the buildings can not be separated from the thick foundation, but the natural generation of the foundation is always different in the structure, the bearing capacity will be different, the volume of compression will be different, resulting in uneven settlement of the housing, and thus cracks. This kind of crack often occurs in the oblique crack of the wall and the oblique crack of the four corners of the door and window hole, it mostly appears as "eight" and inverted "eight".

二、混凝土小型空心砌块裂缝的防止措施

Two. Prevention measures for cracks in small concrete hollow blocks

（一）控制进场砌块的质量

(1) the quality control of the incoming block

1、砌块进场后，施工单位应派专人对砌块的生产日期和出产日期进行严格的检查。检查人员应做好详细的检查记录，监理单位的甲方代表应加强监督，对于没有出产合格证或龄期未到的砌块坚决杜绝上墙砌筑。

1. After entering the block, the construction unit shall assign special personnel to strictly inspect the production date and production date of the block. The inspectors should make detailed inspection records. The representative of Party A of the supervision unit should strengthen the supervision and firmly prevent the masonry from the wall without the production certificate or the old block of age.

2、检查砌块外观尺寸是否满足规范要求，是否断裂，是否有超标的裂缝或是缺棱少角。

2, check whether the appearance size of the block meets the specification requirements, whether it breaks, whether there is excessive cracks or lack of edges and corners.

3、砌块进场后，建设、监理、施工单位应密切配合，按照规范要求及时送检，以确保上墙砌块的强度。

3, after entering the block, the construction, supervision and construction units should closely cooperate with each other in accordance with the requirements of the specifications to ensure timely inspection, so as to ensure the strength of the upper wall blocks.

4、砌块堆放高度要适中，不宜过高。规范规定“砌块堆放高度不宜超过1.6M，应避免雨淋……”。

4. The height of the block stacking should be moderate and not too high. The Code stipulates that the height of building blocks should not exceed 1.6M, and the rain should be avoided.

（二）加强现场施工质量的管理

(two) strengthening the management of site construction quality

1、严格砌筑砂浆的质量要严格砂浆的配合比，控制砂浆的和易性，要做到随搅随用，杜绝已经硬化的灰浆上墙砌筑，以确保砌筑砂浆的质量。

1, strict masonry mortar quality should be strictly mixed with mortar, control mortar and ease, to do with the use of agitate, to eliminate the hardened mortar wall masonry, to ensure the quality of masonry mortar.

2、严格砌筑程序，严把砌筑质量关砌筑前，技术人员要对砌筑进行详细的施工技术交底，提出砌筑中的注意事项。

2, strict masonry procedures, strict masonry quality before the masonry, technical personnel to the construction of detailed construction technology base, put forward the attention in the masonry.

3、严格砌块的含水量现场施工时，不应对砌块浇水，堆放场地要有排水措施，太干的砌块应在砌筑一天前适量洒水湿润，

3. When the water content in the rigid block is constructed in the field, the block should not be watered, the site should be drained, and the dry block should be sprinkled right in the day before the masonry.