论述强新老砼结合的接缝施工措施.docx

1、论述强新老砼结合的接缝施工措施论述强新老砼结合的接缝施工措施在目前的施工技术条件下，较大的现浇钢筋砼水池是不可能将砼一次浇筑完成的，必须设置水平施工缝，分阶段进行施工。如果施工缝处理得不好，将很容易引起水池表面凹凸不平，有麻面、上下池壁错开及渗漏水等现象，严重时将影响使用。而这些毛病完全可以在设计、施工中通过采取一些适当的方法加以避免。Under the condition of the current construction technology, large cast-in-situ reinforced concrete pool is not concrete pouring to

2、be done at a time can be completed, you must set up horizontal construction joints, construction in stages. If construction joint treatment well, will easily cause the pool surface is uneven, there are pits and up and down the pool wall stagger and leakage phenomenon, serious when will affect the us

3、e. And these problems can completely in the design and construction by taking some appropriate methods to avoid them. 2施工缝位置及接缝形式的确定2 construction determined in the form of seam location and seam 现行的砼工程施工规范规定，施工缝的位置宜留在结构受剪力较小且便于施工的部位。对于水池池壁的施工缝，宜留在高出底板表面200500的竖壁上，接缝形式有多种，如凸凹缝、高低缝、平缝、设止水带缝等，根据以往的施工经

4、验，发现目前常用的几种接缝方式均存在着渗漏水的隐患。如采用“凹凸 ”型施工缝，其最大弊端在于施工难度大，且很难保证质量，施工缝处砼凿毛时，极易将“凸”楞碰掉一部分，由此减少和缩短了水的爬行坡度和距离，从而产生渗漏水现象；另外凹槽中的水泥砂浆粉未难以清理干净，使在浇筑新砼后，在凹槽处形成一条夹渣层，影响新老砼的粘结质量，留下渗漏水的隐患。而采用橡胶止水带防水，因止水带是呈柔性的，安装时难于固定，且易在浇注砼时受挤压变形移位，从而容易造成局部渗漏水，而且橡胶止水带易老化失效，也不利于水池的长久使用。Current concrete rules and regulations of engineer

5、ing construction, construction joint shear for the location of the staying in the structure of small and easy to construction sites. For construction joint pool wall, should stay above the base plate surface 200 500 vertical wall and the seams there are many types of forms, such as convex concave sl

6、ot, high and low seam, flat seam, water stop cracks, etc., according to the previous construction experience, found that the current commonly used joint ways there are water leakage hidden trouble. If use bump construction joint type, its disadvantage is that the construction is difficult, and it is

7、 difficult to guarantee quality, cut hair, concrete construction joints will stare blankly convex touch of extremely easily, thus reduce and shorten the creep slope and the distance of water, causing the leakage phenomenon。 Cement mortar powder is difficult to clean in the groove of the other, made

8、after the new pouring concrete, form a slag layer in grooves, affect the quality of new and old concrete bonding, leakage hidden trouble. And use rubber water-stop waterproof, bailey is a flexible, because of difficult to fixed installation, and easy when pouring concrete by extrusion deformation di

9、splacement, thus easy to cause local seepage, and rubber water stop aging failure, also does not favor the pool used for a long time. 根据很多水池施工经验，发现采用400宽、2厚的钢板作为施工缝处的止水带，其防水效果均很好。一是施工方便：将钢板止水带按要求加工成一定的长度，在液压升降机平台施工现场安装就位后进行搭接焊即可；二是不易变形且便于固定，止水板下部可支承在对拉螺栓上，混凝土输送泵上部用钢筋点焊夹住固定在池壁两侧板支撑系统上；三是施工缝上下止水板均有200

10、高，爬水坡度陡，高度也较大，具有较好的防渗漏效果。According to many pool construction experience, adopt 400 wide, 2 thick water-stop steel as a construction joint, the waterproof effect is good. One is convenient for construction, steel plate water stop according to the request processing into a certain length, after the co

11、nstruction site in place of lap welding。 2 it is not easy deformation and easy fixation, water stop plate at the bottom can be supported on the bolt, the upper steel spot welding clamp fixed to the wall on both sides of the plate support system。 Three is the construction joint and water stop plate a

12、ll have 200 high, climbing steep slope, water height is bigger also, has better seepage prevention effect. 3施工缝久模板的安装3 construction joint long template installation 水池施工缝处模板安装质量的好坏，将直接影响到施工缝处砼浇筑的质量。如何避免吊车池壁模板支撑不牢、垂直度控制不好以及上下模板接触不严密呢？现介绍一水池施工中取得较好效果的模板支撑方法。Pool construction seam template installation

13、 quality, will directly affect the quality of the concrete pouring construction joints. How to avoid the wall formwork supporting, verticality control is not good as well as the top and bottom template dont contact closely? Introduce a pool construction obtains the good effect of formwork support me

14、thod. 3.1施工缝以下模板的安装3.1 construction joint in the installation of the following template 首先在C10素砼垫层上安设固定三排60608的钢板，间距为1000，一排设在池壁外侧边缘处，用20长45455的角钢与其相焊，这个角钢的作用是限制池壁外侧模板向内侧移动。另二排设在池壁内侧边缘处，用来安装固定角钢支架，同样用20长45455的角钢与其相焊，这样池壁内侧吊模有了支撑点，且又能固定内侧模板而不致外移。对拉螺栓的横向间距一般为700，纵向间距一般为600，这样便于控制池壁的截面尺寸。施工缝以下第一排对拉螺栓的横

15、向间距为350，且应间隔使用，余下的一半用于施工缝以上模板的固定。角钢可以用螺栓固定在模板上，它的作用是可以将施工缝处砼标高抬40左右。这是因为砼的坍落度较大，经振捣棒振捣后，砼分层明显，水泥砂浆和多余的水分被挤上升，容易形成几厘M厚的砂浆层浮在池壁上面；而这层水泥砂浆将在施工缝处表面砼凿毛时一并凿去，这样能较容易凿出砼中的粗骨料。如不设置角钢，刚极有可能凿毛砼表面时，凿不出粗骨料，且表面很难毛糙，影响新老砼的结合，凿深了又将影响止水带的安装质量，所以设置角钢是十分必要的。First on the C10 plain concrete cushion setting fixed three r

16、ows 60 x 60 x 8 plate, spacing of 1000 , a row in the wall of the lateral edges, with 20 long 45 * 45 x5 Angle and its phase welding, is to restrict the function of the Angle of the lateral wall template to the inside of the mobile. The other two rows in the wall inside edge, used to install a fixed

17、 Angle steel support, also with 20 long 45 * 45 x5 Angle and its phase welding, so the wall inside of the mold has a strong point, and can be fixed inside the template without overseas. To pull bolt spacing is generally is 700 , generally for 600 longitudinal spacing, such easy to control the sectio

18、n size of the wall. Construction joints in the first row of bolt lateral spacing is 350 , spacing and should be used, more than the rest of the half is used in the construction joints fixed template. Angle can be bolted on the template, it is the function of concrete construction joints can be about

19、 40 elevation to carry. This is due to the slump of concrete is bigger, after vibrating stick vibrating concrete stratification, cement mortar and excess water squeezed up, easy to form a few centimeters thick slurry layer floating on the wall。 And this layer of cement mortar will in surface concret

20、e construction joints chisel along to MAO, it can be easy to cut out the coarse aggregate in concrete. If not set the Angle, cut hair just likely to concrete surface, hewn out of coarse aggregate, and the surface is very difficult to coarse, affect the combination of new and old concrete, deep cut w

21、ill affect the installation quality of water stop, so set the Angle is very necessary. 3.2施工缝以上模板的安装The installation of construction joints above 3.2 template 主要是应加强模板的稳定性，可在施工缝上通过对拉螺栓的设置间距与施工缝下部对拉螺栓错开350，使上部模板支撑系统的钢管下延到施工缝以下模板支撑系统第一排预留对拉螺栓处，以达到将施工缝处上部模板支撑系统与下部模板系统联成一体的目的，保证上部模板的稳定性。Mainly should st

22、rengthen the stability of the template, can be in the construction of the set sew through the bolt spacing and lower construction joints on tensile bolt 350 stagger, makes the upper template support system of steel tube under along the construction joint the following template to reserve the first r

23、ow of bolt support system, in order to reach the upper template support system and the lower template construction joints system be installed one of the purposes, to ensure the stability of the upper template. 4施工缝加强新老砼结合的措施4 construction joint enhance combining old and new concrete measures 4.1砼表面的

24、凿毛处理4.1 the surface of the concrete cut wool processing 一般来说，如果砼尚未达到一定的强度，就过早的凿毛，将易影响池壁钢筋、钢板止水带与砼的粘接握裹，对结构受力及防渗漏水不利。但如果凿毛过晚，砼已达到较高的强度，则凿毛施工困难，凿毛效果也不好，而影响新老砼的结合强度。凿毛时间应根据砼强度等级和气温情况综合考虑决定。从“温度、龄期对砼强度影响参考曲线”可知，当砼强度达到设计强度的10%左右时，即可开始凿毛作业。夏季通常是在浇筑砼以后过24h，冬季则可在浇筑砼以后的23d之后进行，应凿出砼中的碎石来，且应将凿毛后的表面清洗干净。In gene

25、ral, if the strength of the concrete has not yet reached a certain, early to cut hair, will easily affect the wall reinforcing bar and steel plate water stop adhesive bond with concrete, adverse to the structure stress and the seepage water. Cut hair. But if too late, has reached the high strength c

26、oncrete, the chisel construction difficulties, MAO MAO chisel effect is not good, and affect the new and old concrete bonding strength. Cut hair time should be comprehensive consideration according to the concrete strength grade and temperature situation decision. From a temperature, age of concrete

27、 intensity influence reference curve, when about 10% of the concrete strength to meet the design strength, cut hair can begin operations. Summer is usually after pouring concrete for 24 h, the winter is after casting concrete, after 2 3 d should be carved out of concrete rubble, and cut hair after s

28、urface should be clean. 4.2施工缝上下设置钢筋网片4.2 construction joints was set steel mesh 在施工缝下面砼的浇筑时，由于砼的离析和分离，接近施工缝处的水泥砂浆偏多，而骨料偏少，使施工缝上下相接处存在一层新老水泥砂浆层相接的素砼薄弱层。由于砼的收缩远小于砂浆层，而砼中的粗骨料对水泥砂浆的收缩有约束作用，致使这层素砼薄弱层内产生裂缝。通常可以在施工缝处设置钢筋网片来防止这种裂缝的产生。即在施工缝平面上下各50处分别设置直径14的二级螺纹钢筋网片于止水带的两侧，沿水池池壁长度方向置于两排池壁主筋之间的素砼薄弱层中，这种钢筋网片可以

29、有效抑制水泥砂浆的收缩，减少裂缝的产生。通过几个水池施工的实践，尤其是在池壁较薄的较大水池中使用钢筋网片，对抗渗漏很有利。施工缝以上砼的浇筑也应按规范要求严格控制砼一次浇筑的高度以及砼振捣棒的插入位置和振捣时间，以免产生对模板过大的侧压力而使对拉螺栓断裂。Underneath the construction joints of concrete pouring, due to the segregation of concrete and separation, close to the construction joints of cement mortar, and aggregate

30、slants little, the construction joint from top to bottom place there is a layer of the new and old concrete plain cement mortar layers in the weak layer. Due to concrete shrinkage is far less than that of mortar layer, and the coarse aggregate in concrete shrinkage of cement mortar has a constraint

31、function, the cracks in the plain concrete thin layer. Can usually be in a setting construction joint mesh reinforcement to prevent the cracks of this. In construction joint plane and set respectively in every 50 in secondary thread diameter 14 pieces on both sides of the water-stop steel meshes in

32、length direction along the pool pool wall between the two rows of the wall the main reinforcement of plain concrete weak layer, this kind of steel fabric piece can effectively restrain the shrinkage of cement mortar and reduce the generation of cracks. Through practice of several pool construction, especially in the larger pool with thin wall steel mesh reinforcement used in the piece, against leakage is very good. Construction joints of concrete pouring should be in accordance with the requirements of specification s