探析采用新型砌块墙体裂缝的防治

摘要：用新型砌块砌筑的墙体发生裂缝，是我国墙体材料革新后产生的一种新的质量通病，已引起人们的重视，本文就墙体发生裂缝的原因及防治措施进行分析和探讨。
Abstract: with the new block masonry wall body crack, is our country to produce a new wall materials innovation quality common fault, has aroused people's attention, in this paper, the wall body crack reason and prevention measures were analyzed and discussed.
关键词：新型砌块 墙体 裂缝 防治
Key words: new block wall crack prevention and control
一、前言
One, foreword
近几年来，建设部大力推广新型墙体材料，加上新型砌体材料比粘土砖有许多优点（自重轻、节能、造价低），使得各种轻质砌块得到广泛使用，而大量使用轻质砌块后，由于设计与施工对砌块性能的掌握不够以及生产监管力度不到位，致使建筑物建成后墙体开裂渗漏问题较多，工程质量投诉很多。为此，有必要对新型墙体材料砌块的特性进行研究分析，并采取合适的设计和施工方法，避免墙体开裂质量通病的继续扩大，确保工程质量。
In recent years, the ministry of construction to promote the new wall materials, coupled with new masonry materials have many advantages than clay brick (light weight, energy saving, low cost), making all kinds of lightweight block is widely used, and the extensive use of lightweight block, due to the design and construction to understand the performance of block is not enough and production supervision does not reach the designated position, after the completion of the building wall cracking leakage problem is more, the project quality complaint a lot. Therefore, it is necessary to study the characteristics of new type wall materials block analysis, and take appropriate design and construction methods, avoid walling quality common fault continues to expand, to ensure the engineering quality.
二、 产生裂缝的原因分析
Second, the analysis of the causes of cracks
1.砌块材质的问题
1. The block material
非承重砼小砌块主要是轻骨料砼。由于轻质砌块容重轻，用作非承重墙体时较红砖有较大优越性。但也应看到它的缺点，一是收缩率比粘土砖大，随着含水量的降低，材料会产生较大的干缩变形,这类干缩变形引在建筑引起不同程度的裂缝。二是砌块受潮后会出现二次收缩，干缩后的材料受潮后会发生膨胀，脱水后会再发生干缩变形，引起墙体发生裂缝。三是砌块砌体的抗拉及抗剪切强度只有粘土砖的50%。四是砌块质量的不稳定。由于砌块自身的一些缺陷，引起一些裂缝，如房屋内外纵墙中间对称分布的倒八字裂缝；在建筑底部一至二层窗台边出现的斜裂缝或竖向裂缝；在屋顶圈梁下出现的水平缝和水平包角裂缝；在大片墙面上出现的底部重、上部较轻的竖向裂缝。另外不同材料和构件的差异变形也会导致墙体开裂。如楼板错层处或高低层连接处常出现的裂缝，框架填充墙或柱间墙因不同材料的差异变形出现的裂缝。这些都是材质问题所致。
Non load-bearing concrete small block mainly is the lightweight aggregate concrete. Due to the light block unit weight is light, when used as a nonbearing wall is red brick has a bigger superiority. But also should see the faults of it, one is the shrinkage rate is greater than clay brick, with the reduction of water content of materials will produce larger shrinkage deformation, the dry shrinkage deformation caused different degrees of cracks in buildings. Secondly, block can appear after be affected with damp be affected with damp secondary shrinkage, dry shrinkage material be affected with damp be affected with damp after inflation will happen, will happen again after dehydration drying shrinkage deformation, cause cracks in the walls. Three is the block masonry tensile and shear strength is only 50% of the clay brick. Four is the unstable block quality. Caused by their own some flaws, some cracks, such as building internal and external longitudinal walls symmetrical distribution among eight crack; In the construction to the second floor window sill to appear at the bottom of the inclined or vertical cracks; Under the roof perimeter beam horizontal seam and level Angle cracks; In large tracts of metope appears on the upper weight, lighter at the bottom of vertical cracks. Other differences between the materials and components deformation can lead to cracking of wall. Like a layer of floor in the wrong place or high and low layer joint cracks often appear, frame infilled wall or column because of difference of different material deformation of the wall between the cracks. These are caused by material problem.
2.构造设计的问题
2. About the design of the structure
（1）设计者重视强度设计而忽略抗裂构造措施
(1) the designer takes the strength design and ignores the anti-crack construction measures
长期以来，人们对砌体结构的各种裂缝习以为常，设计者一般认为砌体的选用比较简单，在强度方面作必要的计算后，针对构造措施，绝大部分引用国家标准或标准图集，很少单独提出有关防裂要求和措施，更没有对这些措施的可行性进行调查或总结。因为裂缝的危险仅为潜在的，不影响结构的安全，没有涉及到责任问题。
For a long time, people used all kinds of cracks of masonry structure, the designer thinks that the selection of masonry compared commonly simple, make necessary calculations in terms of strength, for structural measures, for the most part refers to the national standard or standard atlas, rarely separate types.the requirements and measures are put forward, more not to investigate the feasibility of these measures or summary. Because only for a potential risk of fracture, does not affect the safety of the structure, not involves the liability issue.
（2） 设计者对新材料砌块的应用不熟悉
(2) the designers to not familiar with the application of new material block
设计单位对新材料砌块的性能和新标准的应用尚在认识探索之中，对设计技巧、裂缝预防缺少经验，因此存在或多或少存在设计缺陷。主要有以下一些问题：
Design unit to block new material performance and application of the new standard is still in exploration, the design skill, crack prevention of lack of experience, design flaws so exists more or less. Basically has the following problems:
① 非承重砼砌块墙是后砌填充围护结构。当墙体的尺寸与砌块规格不配时，难以用砌块完全填满，造成砌体与砼框架结构的梁板柱连接部位孔隙过大容易开裂。
(1) the bearing after the concrete block wall is build by laying bricks or stones fill retaining structure. When the wall size does not match block specifications, difficult to block completely filled with masonry and concrete frame beam slab-column connection part of the pore is too easy to crack.
② 门窗洞及预留洞边等部位是应力集中区，无采取有效的拉结加强措施时，会由于撞击振动容易开裂。
(2) Windows and doors hole stress clusters, and the reserved hole position is no Rachel take effective strengthening measures, due to the impact vibration is easy to crack.
③ 墙厚过小及砌筑砂浆强度过低，会使墙体刚度不足也容易开裂。
(3) the wall thickness is too small and masonry mortar strength is too low, can make the wall rigidity shortage is also easy to crack.
④ 墙面开洞安装管线或吊挂重物均引起墙体变形开裂。
Open hole (4) metope installed pipeline wall deformation caused by cracking or hang heavy things.
⑤ 与水接触墙面未考虑防排水及泛水和滴水等构造措施使墙体渗漏。
5. Contact with the water wall does not consider construction measures such as waterproof and drainage and flood water and drip made leakage of wall.
3.砌筑和抹灰施工的问题
3. The masonry and plastering construction problems
由于以往施工单位一直以砌筑粘土砖墙为主，对采用新型轻质砖砌块后砌筑和抹灰施工方法没有掌握，又缺少培训和实践，施工方法、工具、砂浆等都沿用了粘土烧结砖的一贯做法，对日砌筑高度、湿度控制都缺乏经验，加上施工过程中水平灰缝、竖向灰缝不饱满，减弱了墙体的抗拉抗剪的能力以及工人砌筑水平的不稳定都导致墙体出现裂缝。
Because previous construction unit has been with clay brick masonry is given priority to, to adopt new type of lightweight brick after brick masonry and plastering construction method do not have, and the lack of training and practice, the construction methods, tools, mortar, etc are used for clay sintered brick, customary practice, the building height, humidity control are lack of experience, combined with horizontal mortar joint, vertical mortar joint in construction process is not full, abate the tensile shear capacity of walls and masonry workers level of instability led to cracks of wall.
三、 裂缝的控制和防治措施
Three, crack control and prevention measures
1.控制裂缝的原则
1. The principle of control crack
防止轻质材料墙体裂缝的产生，要在材料生产、设计、施工三方面着眼，根据不同材质的砌块执行相应的砌体规范、标准，并制定具体的措施。
Lightweight materials to prevent the cracks of wall, three aspects in material production, design, construction, according to the different material executes the block masonry specification, standard, and formulate concrete measures.
2.砌块质量的控制
2. Quality control block
轻质砌块的质量性能有抗压强度、收缩、抗冻、抗碳性等指标，对于墙体裂缝的产生影响最大的是收缩性，而相对含水率是反映收缩性的重要指标。为此，要求轻质砌块特别是轻集料混凝土小砌块必须经28d养护方可出厂，且使用单位必须坚持产品验收，杜绝使用不合格产品。
The quality capability of the lightweight block compressive strength, shrinkage, frost resistance, resistance to carbon, etc, for the cracks of wall is the greatest influence contractility, and relative moisture content is an important index of contractility. For this purpose, the requirements of lightweight block especially lightweight aggregate concrete small block must through 28 d maintenance before the factory, and use the unit must adhere to product acceptance, put an end to use unqualified products.
3.设计构造的控制措施
3. The design structure of control measures
预防新型轻质砌块墙体裂缝，必须以建筑设计为重点。如果没有针对材料的特殊性，采用适合的砌筑砂浆和相应的构造措施，仍沿用粘土砖使用的砂浆和相应的抗裂措施，必然造成墙体出现较严重的裂缝。设计者可根据《非承重砼小型砌块砌体工程技术规程》、《非承重砼小型砌块砌构造》及有关规范的要求，结合建筑使用功能，各种材料的特性，采取有效的构造措施，方可避免墙体开裂渗漏。
Prevention of new lightweight block wall crack, must be focused on architectural design. If not for the specialty of material, suitable for masonry mortar and the corresponding construction measures, is still using clay brick used in mortar and anti-crack measures, is bound to cause cracks in the wall body appear more serious. Designer can according to the non load-bearing concrete small block masonry engineering discipline ", "non load-bearing concrete small block masonry structure" and the relevant specification requirements, combined with the building use function, various material characteristics, the structure of the effective measures, in order to avoid leakage of wall cracking.
4.施工的控制措施
4. The construction of control measures
（1）确保砖在使用前达到稳定期。
(1) to ensure that the brick plateauing before use.
一般刚出厂的轻质砌块稳定性较差。由于砌体的干缩变形较大，干缩变形的特征是早期发展比较快，以后逐步变慢。因此，使用前应确保材料已达到使用龄期，体积已基本稳定，干缩变形较小的情况下。
General factory-fresh lightweight block stability is poorer. Due to large masonry dry shrinkage deformation, dry shrinkage deformation is characterized by the early development is faster, then gradually slow down. Therefore, before the use should ensure that material has reached the age, the volume has been basically stable, less dry shrinkage deformation.
（2） 要严格控制含水率
(2) we will strictly control the moisture content
轻质砌块使用前对含水率有苛刻的要求，要严格按不同砌块控制上墙时含水率。要选用含水率符合标准的产品外，在砌块上墙前必须要做好防水措施，尽量避免雨期施工淋湿砌块，造成墙体因收缩开裂。
Lightweight block before use on moisture content has stringent requirements, we will strictly according to the different block on the wall when the moisture content control. Moisture content should be chosen accord with a standard product, must be ready before on the block wall waterproof measures, to avoid get wet the rain period construction block, wall due to the shrinkage cracking.
（3）采用正确的施工方法
(3) the right construction methods
必须根据轻质砌块干缩变形相对较大特点，采取正确的施工方法和控制措施。重点是砌块的砌筑方法及洞口处理两方面，主要有以下一些要点：
Must according to light weight block relatively dry shrinkage deformation characteristics, adopt the right construction methods and control measures. Emphasis was on block masonry method and the hole processing two aspects, mainly has the following some points:
① 施工现场的砌块应按规格堆放，堆放高度不宜过高(一般不超过1．6m)，并应采取防雨措施以防雨淋，砌筑前，砌块不宜洒水淋湿，以防相对含水率超标。
(1) the construction site of the block should be piled up according to specifications, stacking height should not be too high (generally not more than 1.6 m), and rainproof measures should be taken to prevent the rain, masonry, block should not be water wet, the relative moisture content exceeds bid in case.
② 砌筑时应尽量采用主规格砌块，并应清除砌块表面污物及底部毛边，尽量对孔搭砌，砌体的灰缝应横平竖直，灰缝应饱满，以确保墙体质量。
(2) masonry block should be adopted as far as possible the main specification, and should be cleared surface dirt and burrs at the bottom of the block, as far as possible to hole on build by laying bricks or stones, masonry mortar joint should be horizontal even vertical, mortar joint should be full, in order to ensure quality of wall.
③ 对不同材料严格控制不同的日砌高度，墙顶3m高的砌体必须隔日顶紧砌筑，避免引起接合部位开裂。
(3) day of build by laying bricks or stones of different materials, strictly control the height, the top 3 m high masonry wall must be on top masonry, avoid causing joint part cracking.
④ 不能随意砍凿砌块，禁止采用不同材料混砌，否则容易造成墙体开裂。
Hewing and block (4) can't just ban using different material mix build by laying bricks or stones, otherwise easy to cause the wall cracking.
⑤砌块与混凝土柱连接处及施工留洞后填塞部位增加拉结钢筋，锚固钢筋必须要展平砌入水平灰缝，
(5) joint and construction for brick and concrete column hole filling area increased after Rachel reinforcement, anchoring reinforcement must be flattened build by laying bricks or stones into the horizontal mortar joint,
⑥ 严格控制墙体孔洞预留及开槽的处理，避免削弱了墙体强度，对洞边空心砌块应填实及加设边框等处理以确保墙体整体性。
6. Strict control wall of reserved holes and slot processing, avoid weakens the wall intensity, the hole hollow block should be filled, and added a border processing to ensure integrity of wall.
四、结语
Four, conclusion
综上所述，各种轻质砖墙体开裂的原因较多，但是，只有严格执行有关砌体规范，从生产、设计、施工各方面层层把关，采取有效的控制措施，针对砌体开裂精心施工，才能消除新型砌块墙体开裂的质量通病。
To sum up, for a wide variety of light brick walling is more, but only the strict about masonry standard, from all the aspects of production, design, construction, cengcengbaguan, take effective control measures, aimed at cracking of masonry construction carefully, to eliminate the common faults new block wall crack.