order to ensure the correct dimensions of the steel work, special tools like clamps can be made to control the same.
5.2.3.4施工中钢筋的绑扎接头位置应相互错开.从任一绑扎接头中心至搭接长度L1的1.3倍区段范围内,有绑扎接头的受力钢筋截面面积占受力钢筋总截面面积的百分率,应符合以下规定:受拉区不得超过50%。绑扎接头中钢筋的横向净距S不应小于直径D且不应小于25mm。During execution, the binding joints shall be not in one line. The center of the joint to the overlap length (L1)shall be less than 1.3 L1. The percentage (the cross section of the steel bars under stress with binding joints be divided by the total cross section of the bars under stress) shall comply with the stipulation: the length under stress shall be less than 50%. S(net space) shall no be smaller than D (diameter) but not small than 25 mm.
5.2.3.5对电渣压力焊,气压焊要检查接头外观质量,包括焊口突出表面高度,弯折角度(不大于4或70/1000)和轴线偏移等项内容,钢筋接头一定要离开拐点≥10D,不准位于构件的最大弯距处。施工中用无齿锯将钢筋端口切平,先焊高位筋,后焊低位筋。For welding, it is imperative to check the joint’s outlook, the joint itself, the bent angle(no greater than 4 or 70/1000) and the axis deviation. The joint shall be away from the inflexion (greater or equal to 10D). During execution, cut the bar end even, first weld the high level bars and then the lower ones.
5.2.3.6钢筋保护层厚度The Concrete Cover：钢筋保护层尺寸控制是否准确及钢筋位置是否满足设计要求是创优检查的一项重点内容,也是存在问题较多和不易控制的问题,施工中应采用砂浆垫块或塑料垫块控制保护层厚度，对于柱子钢筋的定位一般采用定位卡在浇筑砼前将定位卡套在柱筋顶端,用绑扣将柱筋紧靠在定位卡上,控制钢筋间距位置,下部用塑料垫块控制保护层厚度。The proper concrete cover and the location of the reinforcement steel shall be checked. It is the main checking for creating the first class quality work for many problems happened in this regard. Cement mortar and plastic spacers made of are used to
control the concrete cover. The spacers are usually fixed on the top of the column reinforcement steel and at bottom, plastic ones, to control the concrete coverage.
5.2.3.7钢筋在绑扎时注意间距及钢筋的规格，钢筋间距，锚固长度应符合图纸及规范要求,对于悬挑结构，钢筋的摆放应正确。钢筋保护层厚度要保证，还要注意不得漏扣以及绑扣丝向时，防止其锈蚀污染砼外表面。When fabricating, attention shall be paid to the space between bars and their diameters. The anchor length shall comply with the requirements of drawings and the specifications. For those cantilever structures, the reinforcement steel hall be positioned properly and the concrete cover shall be ensured. No stirrups are missing and the end of the binding seams shall be bent inward to avoid the concrete surface from being stained and rusted.
5.2.4砼工程The Concrete Work
5.2.4.1施工前应进行砼配合比设计,首先根据现场实际所用原材料的性能及对砼的技术要求进行计算,再经试验室试配及调整,定出既满足设计和施工要求,又经较经济合理的砼配合比。当原材料发生显著变化时,应重新进行配合比设计。施工过程中严禁随意改变配合比。Before execution, the concrete mix ratio shall be designed. Based on the features of the materials at site and the technical requirements of the concrete, calculations shall be worked out and adjustments shall be made in the lab so as to obtain the proper concrete mix ratio which complies with the design and technical requirements for the execution and is also reasonably economic. When there are changes in the materials to be used, then new and proper mix ration shall be worked out. However this ratio is strictly forbidden to be changed at will.
5.2.4.2施工前必须对模板、钢筋工程进行隐蔽工程验收：检查模板标高、位置、构件的截面尺寸是否满足设计要求，构件预留拱度是否正确。检查模板接缝、阴阳角平整度和支撑情况，检查钢筋、预埋件的规格、数量、安装位置及构件接点连接焊缝隙是否与设计和施
工规范的要求相符合。检查水、电、暖等设备管道的位置、数量是否准确无误。经班组、工种间自检、互检、施工单位质检员专职检验后报监理或建设单位驻工地代表检查验收。经以上各项检查无误并办好隐蔽工程验收手续后方可浇筑砼。砼浇筑时应有木工、钢筋工配合看模板和看钢筋，以保证模板、钢筋不变形。Before concrete casting, form work, reinforcement steel work and those hidden items shall be checked. For formwork, check its level, position, parts and elements to see if they all comply with the designing requirements. Check the arch if it is correct. Check the joints, corners supports, reinforcement steel, embedded elements and their numbers, locations, welding points, water and electrical pipes, ventilation ducts and shafts, their numbers and locations, and etc, till all these comply with the designing requirements and specifications. Checks are carried out within the work groups, among the work groups of different trades, and by the professional quality inspectors and then submit to the Supervisor and the representatives of the Client for approval. Only when the above- mentioned checks including on hidden items are completed without finding any mistakes, can concrete casting be carried out. During casting, carpenters and rebar men shall be at the spot to ensure that no deform of either form work or reinforcement steel happens.
5.2.4.3本工程的主要结构均采用泵送商品砼的方法，所以砼拌和物除满足设计规范规定的强度、耐久性要求外，还需满足管道输送的要求，即砼拌和物须有良好的可泵性。为保证施工质量、进度目标，须认真选择符合国家有关规定标准、具有较强实力及生产能力、有良好信誉的专业商品砼生产厂家，严格控制原材料质量。Casting for the main project structure twill be dong by the concrete pump. So the concrete shall comply with the intensity and endurance by the design requirements and specifications, and also conveyable through the pipes by the pump. In order to guarantee the execution quality and progress target, it is imperative to choose the ready made concrete supplier with good
credit and rather powerful, who supply the concrete up to the state standards. Besides the quality of the materials shall be strictly controlled.
5.2.4.4砼泵送时的施工方法The execution method：（1）砼搅拌运输车出料前，应高速转动30s后反转出料；Before discharge, the trans-mixer shall properly mix 30 seconds;（2）泵送砼前，先把储料斗内清水从管道泵冲出来，达到湿润和清洁管道的目的，然后向料斗内加入与砼配比相同的水泥砂浆（或1：2水泥砂浆），润滑管道后即可开始泵送砼；Before pumping the concrete, all the water in the storage drum and pipes shall be cleared away, then add the same mix ratio mortar (1:2 cement mortar) to lubricate the pipes. After that discharge the concrete;（3）开始泵送时，砼泵操作人员应使砼低速运转，待顺利泵送后再提高运转速度，加大行程，转入正常的泵送，若砼供应不及时，宁可慢速间歇泵送，也要保持连续泵送；when starting, the operator shall pump the concrete at rather low speed, and then speed up until normal operation. If the concrete supply is not in time, keep the slow and continuous pumping. （4）砼泵送即将结束前，应正确计算尚需用的砼数量，并及时告知砼搅拌处；Before pumping coming to an end, work out the volume of th concrete needed and inform the batching plant of the same;（5）砼泵或泵车使用完毕应及时清洗。Trans-mixer should be timely cleaned after casting.
5.2.4.5泵送砼的浇筑顺序Casting procedures by the pump：（1）采用砼输送管输送砼时，应由远而近浇筑；From far away to closer places;（2）在同一区域的砼，按先竖向结构后水平结构的顺序，分层连续浇筑；For the same area, first the vertical structures, then the horizontal ones, layer by layer;（3）当不允许留施工缝时，区域之间、上下层之间的砼浇筑间隙时间，不得超过砼初凝时间；If no joints are permitted, the time difference between two areas or two layers shall not longer than the time concrete sts.（4）当下层砼初凝后，浇筑上层砼时，应按施工缝的规定处理。When casting, if the lower layer of concrete has set, then joint has to be made between the upper layer and the lower one.