1。预制盒梁的质量接受和质量控制。预制的施工过程流程图。对底部模具的检查和维护,霉菌释放剂的安装支撑和其他底部的钢钢杆被提起到安装端模具顶板钢杆中,并调整了混凝土倒入。提取橡胶管以覆盖洒水器并修复拆卸的末端模具,松动的内部模具支撑,并拉出内部霉菌初始张力梁的身体洒水器和天然维护真空吸尘器灌浆成品梁检查通道,盒子梁移至光束存储底座,以使其移动到光束存储底座,以使所有预应力(最终拉伸)的锚固密封和将成品梁的锚固密封和维护到仓库,维护和维修侧模,霉菌释放剂钢条和橡胶提取管调整内模具内部模具吊顶,底部网络钢杆钢筋检查钢杆检查钢筋入口钢杆入口检查屋顶钢杆钢筋钢筋绑定并发出混凝土混合混凝土制造和抽水施工混合率,用于进入现场检查和张紧设备校准,编织,孔清洁,通过捆绑捆绑的束缚,锚固式灌浆材料混合,混凝土混合,运输和防水涂层涂层的固定涂层钢筋的固定电线的混凝土原材料条弯曲,检查钢筋弯曲,嵌入式板的检查等,检查和维护,完成终端模具以制成混凝土
2。测试件处于相同的条件和标准维护状态,指定的强度达到指定的强度,并完成了指定的强度,并且测试了测试件并完成了检查。测试件的技术信息已充分维修,并将内部模具底部的网络加固捆绑在一起。加固杆的建设1。进入现场的钢条必须具有工厂证书。每批钢筋都由同一品牌,炉子编号和相同规格的钢条组成。钢筋存储在干燥的地方。钢筋距离地面20厘米,并根据炉子编号,不同的规格和批量编号分别存放。不合格的钢筋必须具有明显的迹象,以防止混乱,并且不会污染有害物质,例如油,酸,碱和盐。 2。将根据采样基准和频率对进入现场的第一批钢条将由实验室进行采样,并将检查。完整的检查项目是:拉伸强度,屈服强度,伸长和冷弯曲。 3。钢杆实验室的随机检查项目是:拉伸强度,屈服强度,伸长和冷弯曲。 4.选择已通过每批钢筋(不超过60吨)的外观检查的钢。
3。肌腱采样。测试后,如果一项失败,则将测试数量的数量两倍,以执行对不合格项目的第二次重新检查;如果一件项目仍然失败,则一批钢筋将被视为不合格的产品。 5。钢筋处理,结合和钢架提升。加固框架举起是由门制成的悬挂框架。悬挂框架具有足够的强度和刚度,以确保在提升过程中不会发生变形和扭曲。安装钢筋时,在钢棒和模板之间使用C55混凝土垫,并绑在最外面的钢杆上以支撑垫子。垫子的强度与梁体的强度相同。垫子以李子开花形状排列,彼此分开并分散,并且必须确保垫子的数量确保垫子的数量不少于4件/m2。安装钢杆骨架时,有必要确保钢杆笼处于准确的位置,而不是倾斜或扭曲,并且保护层的厚度满足要求。骨骼到位后,再次检查保留管道的任何未对准以及定位网格是否正确。仅通过确保骨骼和管道的准确性和结合
4。只有在坚定的时候才能构建模板。钢杆框架预先制动并安装到位之后,安全和质量部的质量检查工程师应进行检查,重点是检查桥支架,防倾梁停止嵌入式板,全面的接地终端,接触网络支撑和锚垫板等。安装和位置,检查钢筋保护层,垫子的数字,位置和紧密度,并在自我检查后向监督工程师报告接受,并进行相应的记录和档案。 2。模板的安装和使用盒围栏模板由底部模具,侧模,末端模具和内模组成。底部模具通过嵌入式零件焊接到底座。侧模是一种积分的钢模具,与底座铰接在一起,并配备了相应的安装。 ,删除调整机构,内模是一种积分自动液压缩放内部模具。模板和支撑必须具有足够的强度,刚度和稳定性,以确保形状的准确位置,梁体每个部分的大小和嵌入式部件的尺寸。面板应保持光滑,而没有局部凹面和凸面或不稳定的阶段。所有钢制模板的关节必须平坦而紧密,并且必须保持拧紧的螺栓
5。模板中的缝隙必须紧密且完整。为了确保模板结构的稳定性,两侧的模板通过螺栓连接到基本模具并铰接到底座,然后用千斤顶腿垂直拧紧外侧。通过调节千斤顶(或可调节螺钉)以旋转侧面模具围绕基座上的铰链轴。当模型的高度符合梁主体的设计高度时,模型的倾斜角也与两侧的束主的设计倾斜角相匹配。将模板紧密连接到底部模板后,使用底部拉螺栓将侧面模具连接到整个侧面。模板安装和调整完成后,有必要确保拉杆处于均匀拧紧状态,腿部处于均匀拧紧的状态。在使用模板之前,表面应干净整洁,灰尘,水泥浆,生锈和其他碎屑应被完全去除。必须正确且均匀地施加模具释放剂,然后应将相关的嵌入零件正确固定在模板上。必须严格禁止霉菌释放剂。或流到嵌入式零件上。模板上的释放代理必须很小,甚至
6。在涂抹之前,必须将使用释放剂施加的拖把扭转为一半干燥。如果刷牙太多,则必须使用干拖把来去除多余的释放剂。释放剂可以覆盖模板的整个表面,而无需明显的结果。厚度就足够了。表1表1表1模板安装尺寸允许偏差表序列号项允许偏差1模板的总长度±10mm2±10mm2基本模板宽度 +5mm,03基本模板中心偏差2mm44桥面板中心线和设计位置偏差10mm5网络中心线和设计位置偏差10mm6跨分布中心位置偏差5mm7模板倾斜偏差38底部模具不平衡2mmm9桥面板宽度±10mm10 web厚度 +10mm,011底板厚度,011 +10mm,012顶板厚度 +10mm,013跨分布板 +10mm和-5mm模板的厚度必须在使用前进行测试,并且
7。您只能在通过接受后才使用它。每个配件必须足够。通过检查和接受的支撑板用固定螺栓(4×M6.5)固定在底部模具上,并且支撑板的位置必须满足桥梁跨度的偏差要求。可以在支撑板和基本模具之间放置海绵,以防止浆液泄漏。在安装侧模板之前,请检查板表面是否平坦且光滑,是否有凹形和凸形变形和残留浆,应清洁模板接口。检查是否有任何缺陷或变形会影响所有碰撞的模板的末端和模板底部的末端的使用,以及振动器支架和模板的焊缝处是否有裂纹和损坏。如果有的话,应及时进行焊缝和维修。安装侧模后,底部模具将用螺栓牢固地连接。调整其他紧固件后,检查整体模具的长度,宽度,高度和平坦度,并保留记录。如果法规不符合要求,则应及时进行调整。根据表1所需的允许误差范围严格检查组装后的光束主体模板的相关尺寸,尺寸误差为
8。必须在使用之前调整和接受极限零件。钢模具应以准确的位置和紧密的连接安装,侧模和底部模具之间的接头应在没有泥浆泄漏的情况下紧密连接。在安装末端模具之前,请检查板表面是否平坦且光滑,是否有凹形和凸形变形和残留浆。应清洁末端模具管道的孔。将软管或波纹管插入末端模具的各个孔后,将端模安装在适当的位置。在安装过程中,检查它是否位于设计位置。为了确保末端模具的垂直性,除了根据上述相关规定进行检查和调整外,还必须测量其在基座表面上的理论位置并做出固定标记点。检查模板时,您可以使用悬挂球直接提升点。尝试将其错误接近零。末端模板的预留孔的偏差不应大于设计位置的3mm。为了确保桥梁的准确全长,末端模板必须达到准确的尺寸位置,并且将端模螺栓固定在底部模具上。 3。混凝土结构1。混凝土混合原材料进入仓库
9。1。进入仓库之前检查沙子和碎石材料。如果粘土块和污泥含量超过标准,则不得使用它们。 2。筒仓不得混合材料,严格禁止生产混合材料。 3。筒仓应每月两次洗涤一次,以保持清洁。必须严格按照实验室通知进行混凝土成分和计量混凝土成分,并且测试人员应在现场进行生产控制。 1。应根据测量部规定的检查周期进行混凝土批量计量仪器的校准。如果在生产过程中发现异常,则应在时间上进行校准。 2。打开前检查称重设备。根据生产混合率和测试仪的评论,考虑了排泄量。打开后,应在前三个板上检查出排出的长袜的实际重量。之后,将成分误差指定为1%的水,混合,水泥和2%的沙子和石头。 3.用水控制:尝试通过参考生产混合比的用水量混合混凝土,并根据实际测量的低迷调整用水量。但是当实际的用水和生产分配
10。当组合比大的比率很大时,必须确定并调整原因。聚集体的水分含量应经常测量,并且在下雨天和下雪的天气时应增加测量的数量。用水的调整应由建筑工地测试人员决定。 4。还原剂还原器的量由实验室确定。提前准备了还原溶液,应定期去除在容器底部沉淀的固体炉渣和碎屑。应随时检查水还原剂解决方案的特定重力以符合测试要求,并且制剂的比例,比重和检查结果应在生产记录中填充。 5。混凝土混合(1)当选择束体的混凝土混合物比时,应确保混凝土满足设计强度和高强度在早期和收缩蠕变的要求。水泥比为0.38,每立方米的混凝土水泥量不得超过500kg。 (2)应测试和比较测试,并应提前准备几个理论混合比,例如夏季产量,冬季生产,超强1015%等,以适应各种生产条件的变化。
11。混合比的使用应由首席工程师批准。 (3)在将每个光束倒入市场之前,一个敬业的人应负责组织以下准备工作:获得生产混合率通知并确认这次倒入的混凝土的骨料,水泥等已经到达混合站。检查聚集体和水泥的质量(包括水泥标签和相关的测试报告)。混凝土混合站和输送设备处于正常状态,织物杆覆盖范围是可靠的。该设备应进行测试并确认状况良好。混凝土的低迷由实验室控制,并且必须在打开后测试前三个混凝土板的低迷。在混凝土混合过程中,应及时进行与混凝土相关特性的测试和观察(低迷,轻松,水分保留)。混合混凝土应增加沙子和石材水分含量测量的频率。 6。注入混凝土底板:首先从网的顶部放电,侧振动的开放部分,底部振动用于促进混凝土的流动。当混凝土从内部成型板中流出时,请使用插入振动器。
12。指导和振动很紧。如果混凝土在底板的中间不关闭,则必须从内部模具填充孔中排出。当混凝土流入内盒的底板中时,必须用手动铲子进行补充。应控制底板的混凝土高程。 Web灌注:Web灌注应在左右对称,过程斜率应为1:41:5,水平分层灌注厚度不应超过300mm。网络的底部是振动振动,网络的内侧是高频粘附振动,网络的外侧是电源频粘附振动,网络的中部和上部也插入了插入振动和引导排放。倒入混凝土时,您应该注意以下要求(1)在光束填充过程中,应分配一个特殊的人来查看模板和钢筋。如果螺栓和楔子松动,请及时拧紧并延伸。如果发现关节开口和其他泄漏,则应及时阻止关节开口和其他浆料。严格来说,如果钢筋变形,则应及时修复它们以确保正确的位置。嵌入的零件在移位时应纠正。如果振动器被燃烧或失败,则应及时更换它们。 (2)输注应连续进行,一口气完成,并与两层连续混合
13。在室温下,混凝土倒入之间的间隔不应超过45分钟。 (3)混凝土出口不应太高,无法避免混凝土分离。在输液期间,它应该在3M内沿网络移动。应控制放电速度以确保均匀排出。不允许排放浓缩。应移动打孔管道,钢架变形,并应防止混凝土梗塞引起空心。 (4)应在适当的时间进行第一个级别和第二浆涂抹表面,以使其光滑和排水平稳。 (5)应防止振动和过度振动,并严格禁止泄漏。 (6)在夏季生产期间,应采取措施来控制沙子,砾石骨料和水的温度,以及混凝土成型温度不应高于30。(7)当建筑工地的平均白天和夜间温度为小于+5(或最低温度小于-3),可能会产生冬季产量。 (8)必须小心填充灌注记录。 7。混凝土标本(1)用于制造样品的混凝土应在输送管的出口和16组梁体试样处随机采样
14。(三组模制样本)。 (2)样品应在特殊的振动台上振动(符合JG/T3020-94)。 (3)测试件的目的是确定拆卸混凝土的强度(用梁维护),一组识别早期预应力混凝土的强度(用梁维护)和四组来识别强度的强度当第二阶段的预应力(用梁维护)时,五个组的混凝土强度(标准固化)确定了一组,确定了一组用于混凝土强度28天的混凝土强度(梁固化),三组。模制标本和一组保留。实验室应将混凝土强度测试报告表分发给技术室和安全室。 8。提取软管(1)萃取软管提取时间的提取时间不会导致变形,塌陷,裂缝或未提取孔。在室温下,当强度达到48MPA(200温度)和表面温度约25时,“比早晚迟到”,拉软管的时间是在将混凝土倒入300分钟之后的时间
15。拔出橡胶管,无需在触摸手时留下任何坑。 (2)预防措施:卸下管道后,及时拆下锚垫板上襟翼中的残留水泥浆液和灌浆孔。拔下管道后,检查孔中是否有任何堵塞或倒塌的孔,如果有任何异常,请及时处理它们。在安装打孔橡胶管时,应在软管上设置标记kaiyun.ccm,以确保将一个固定端留在外部,另一端连接到它,并且不会转身。软管的设计为从跨度的中间出发,接头用铁管紧紧地侧面,插座长度不少于300mm,并且必须密封接头,而不会泄漏泥浆。 4。卸下梁模板时,梁混凝土强度应达到设计强度的60%以上;横梁混凝土的核心和表面之间的温度差,盒子内外开yun体育app官网网页登录入口,表面层和环境不应大于15,并且温度变化急剧变化,不建议在相同的相同的情况下卸下模具时间,应确保光束的边缘和角落。应使用与光束混凝土相同的条件固化的标本的强度来确定拆卸时间。卸下末端模具后,释放内部模具以进行假装,并等待梁主体进行。
16。初始张紧后,可以去除内部模具,并可以去除外模。严格禁止将带拉杆,固定螺栓和其他配件等配件提前拆除。嵌入零件的固定螺栓可以提前正确卸下。倒入混凝土后的68小时可以拆除(严格禁止在填充后拆除),而且拆卸太晚并不容易。还必须提前卸下排水管的定位管盖和模具,但是在卸下模板后,必须从排水管的下端卸下定位管。严格禁止强行撞到排水管并损坏排水管。侧模必须及时删除。卸下检查的嵌入零件上的固定螺栓。仅在完全取出固定螺栓后才可以去除螺栓。卸下模板(侧模)的原理是拉上顶并同步向下拉下,并且必须统一地拉出上和下顶的操作。 。去除模具时,必须尽早用桁架卡车抬起要去除的模板,以防止模板倾倒。当不使用桁架卡车抬起模板支架时云开·全站体育app登录,严格禁止将其删除。卸下末端模具时,您必须注意桁架,模板和操作员之间的密切合作,以使移动模板缓慢甚至更新。
17。均匀地同步和坐标,并严格避免在梁上损坏嵌入的部件(U形螺栓等)的现象,或引起模板的变形和变形。去除形式时,请避免损坏梁体的混凝土和形式。严格禁止击中或撬动以避免对混凝土边缘和角落的损坏的部分变形或撬动。卸下光束模板(配件)时,必须确保对混凝土的内部和外部质量没有不利影响。如果单个模板不容易删除模具,则必须仔细抛光模板的相关部分,并校正,以确保下一次模具拆卸工作的平稳进度。 5。在混凝土固化期间进行天然混凝土固化,应服用覆盖,包裹,浇水,喷洒和洒水等措施,以保湿和滋润,以确保混凝土不会失去水和干燥,并保湿直到规定的年龄。当混凝土表面处于潮湿状态时,混凝土固化还可以快速使用亚麻,稻草窗帘和其他材料覆盖或包裹裸露的混凝土,然后使用塑料布或画布覆盖亚麻,稻草窗帘和稻草窗帘。
18。用保湿材料覆盖。在涂层期间,涂层应完好无损,彼此重叠,并且内表面应具有冷凝水液滴。有条件的区域应试图延长混凝土覆层,保湿和固化时间。在任何固化时间全面检查了进入该地点的第一批预应力钢筋。有关完整检查,请参见表3。材料和设备部将通知实验室。实验室将安排一个特殊的人取样,并委托中心实验室进行全项目检查。放松率将委托给广州Tiecheng测试中心进行检查。只有在通过检查时才能使用。 (2)必须分批接受预应力的钢筋。每批均由由相同品牌扭曲的钢丝链组成,每个批次的重量不大于30T。检查每批钢筋的表面质量和尺寸一一。为每批钢链进行测试
19。一组,从其中任何一个拿走3个板,并为每个盘子服用1个测试件。如果每个批次少于3盘,则应按磁盘进行检查。采样时,将样品从每盘钢链的任何端切下。测试片的长度为每组1m,每组3件,每组松弛标本2.50万,每组2件。当有一个不合格的测试结果时,除了确定不合格的光盘之外,还必须从同一批未经测试的钢绞线盘中取出样品的数量,以重新检查无限制的项目。如果有一个不合格的人,则不得交付整批钢质搁浅的电线,否则将在一一通过检查后交付货物。表3钢筋检查项目,质量要求和检查频率项目采样项目频率完整检查项目质量要求1每批损坏的每批钢筋不得超过30吨,相同类型,相同的规格,相同的批次数量,相同的批次数量,260kn2屈服负载234kn3弹性模量195±10GPA4终极伸长3.55松弛1.0(
20。名义力601000H)2.5(标称力701000H)4.5(标称力801000H)6直径+0.40,-0.20(3)在预先层状的钢链进入现场后,材料设备部门和安全部门和安全部门被连接。检查钢链的外观。钢丝线中必须没有折断,交叉或跨划线的钢丝。表面上必须没有油,油脂和其他物质。允许轻微的漂浮生锈,但不得允许可见的腐蚀坑。松散的钢丝链的直率:取和弦长度为1m,绳子和弧的最大自然向量高度不得超过25mm。 (4)在预应力钢筋的装载和处理过程中,严格禁止扔,碰撞或拖动。在举起期间外包橡胶或隔离,以防止对钢链损坏。 (2)钢质束线1的切割,编织和螺纹。预应力的肋骨长度由技术人员计算,并由梁和院子的首席工程师进行审查,以向建筑工作团队移交材料。钢链线束
21。孔位置不同,其长度不同。它们必须提前编号和标记。材料列表应相应排放。编号后,铁板两端都悬挂,并分别指示并分别存储数字以避免混淆。 2。预应力的钢链的切割长度=工作长度 + 1900mm。 3。预应力的钢链是用砂轮切割的。首先将切割钢丝线之前的末端与铁线绑在一起。在放电过程中,切割的两侧被绑定然后切割。严格禁止使用弧形切断,并且不得受高温焊接火花或接地电流的影响,并且在排出后不得分散钢筋。 4。钢链排放后,必须梳理预应力的钢丝线,以确保钢丝链是笔直并且不会扭曲的。当两批钢质链线之间的差异超过5GPA时,不得合并一堆(也就是说,它不能渗透到一个孔中)。编织与20#铁线绑在一起。绑定时,应将一端冲洗到另一端。一根电线应每11.5米绑住,并应放置电线弯曲。
22.编织后不弯曲而不是扭曲。结合完成后,根据光束规格将其放置以防止滥用。 (iii)锚和固定装置1。所使用的工作锚,工具锚和极限必须是来自同一制造商的产品,并且不能单独使用来自不同制造商的产品。进入网站时,材料和设备部必须根据工厂的证书和质量证书检查锚绩效类别,型号,规格和数量,并提前通知安全和质量部门及时检查。 2。锚定产品中使用的材料必须满足设计要求,并得到省级和部长级的批准;有机械性能和化学组成,质量保证证书或验收测试报告的资格证书。每批锚点都由由相同类型的产品,相同批次的原材料和相同过程产生的锚组成。每批1,000套将根据一批检查。 3。外观检查:每批绘制10个(每批组1,000套)
23。%和不少于10套外观尺寸检查;每批都会从每批绘制硬度检查,并且不少于5套检查,从每批中绘制了至少5%的碎片以进行硬度检查;绘制静态负载锚定能力3组进行检查。 4。硬度检查:从每批中提取5%的锚点,不少于5组,对具有硬度要求的零件进行硬度测试,并为每组多孔夹式锚固夹提取至少5件。 。每个部分都进行了3分的测试,其硬度必须在设计要求之内。如果一个零件失败,则将零件数的数量翻倍以重新测试。如果一个部分仍然失败,请一个又一次地检查它可以使用它。 5。静态负载锚定性能测试:当质量证书不完整,不正确或对质量有疑问时,通过上述两个测试后,将从同一批次中提取6组锚(夹子或连接器)以形式3预订。如果没有测试件
24。如果满足要求,将对锚固量(夹子或连接器)的数量进行两倍,以重新测试。如果仍然有一个不符合要求的测试件,则锚点(夹子或连接器)是不合格的产品。 6. The use of anchors requires that the anchors for prestressed ribs must be cleaned before installation and use. When installing the anchor, it is required to be centered with the hole. During the tensioning and anchoring of prestressed ribs and anchoring, the anchor must not be vigorously knocked or vibrated to prevent the prestressed ribs from flying out and injuring people due to the failure of the anchor. After the prestressed rib is anchored, if it is necessary to relax for some reason, a special relaxation device is used to loosen the anchor and cannot be cut off directly. After the prestressed tendon tensioning and grouting are completed, permanent protective measures (anchor sealing) must be implemented as soon as possible for anchors exposed to the outside of the structure to prevent moisture and other harmful media from being immersed in. (IV) Construction technology 1. Use requirements for tensioning equipment Tension equipment (jack, oil pump, oil meter) is used and stored by a dedicated person, and is regularly maintained and calibrated (calibrated) (checked)
25.). 2. Before the calibration and tensioning of the jack, the jack should be calibrated. The calibration should be determined regularly based on the equipment status, frequency of use and temperature. The validity period of jack calibration is one month and must be calibrated when it expires. Cards must be established for reference for each calibration. If the jack has been overhauled or has serious oil leakage, it must also be recalibrated after dismantling and repairing. The jack must be calibrated with the calibrated oil gauge. Before calibration, test the jack and test the pressure three times. Only when the oil leakage is confirmed to work normally can the calibration be performed. Through calibration, the linear regression equation of the oil pressure gauge and the corresponding pressure (top force) is calculated. When the regression coefficient representing the approximation between the regression equation and the real function of the experimental data is 0.9999, it is considered to be qualified. Otherwise, the cause will be found and recalibrated. 3. The calibration of the oil meter must be sent to a qualified metering department for calibration every month and is calibrated by the beam metering room every week. The hydraulic gauge must be re-marked in the following cases
26. Set: The validity period of the hydraulic gauge calibration reaches one month. , the oil meter exceeds the allowable deviation or a failure occurs when used. , those who suffer violent vibration, impact, pointer non-zero and pointer instability during use. 4. Prestress tensioning process Prestress tensioning is a special process for box girder quality control. The safety and quality department sends a special person to conduct full monitoring. The laboratory provides the strength and elastic modulus of concrete to the engineering and technical department, and the tensioning technology The person in charge prepares a tension notice, which includes: strength, elastic modulus, age, oil meter reading, design tension stretching value, load holding time, etc., and explains to the tension team leader. Before tensioning, the monitoring personnel carefully checked the compressive strength, elastic modulus value and age meeting the requirements, and confirmed the tensioning equipment, process parameters, and tensioning personnel, and during the tensioning process, the tensile stress, measured elongation value and Monitor the quiet stop time. If there is a problem, stop immediately and carefully find out the cause, and then tension after eliminating it. Box beam tensioning
27. Three stages: The first is pretension, mainly to prevent early cracks from occurring in the beam body. When the concrete strength of the beam body reaches 60% (30MPa) of the design strength, the end mold will be removed and the inner mold will be loosened, and the inner mold will be released. Modular tensioning, when the concrete strength reaches 33.5MPa (report form is issued by the laboratory), pre-tensioning can be performed according to the design requirements; the second time is initial tensioning, and the concrete strength in the beam body reaches 803.5 Mpa (43.5) When performing during Mpa, the rear beam body can be lifted and moved out of the beam-making platform. The third time is final tensioning, and the process is carried out on the beam pedestal, after the beam body concrete strength reaches 53.5Mpa and the elastic modulus reaches 35.5Gpa, and the age period is no less than 10 days. The concrete strength and elastic modulus during tensioning are required to be based on the pressure test report of the concrete test block cured on site with the same conditions. Before tensioning, there must be a notice of oil meter reading issued by engineering and technicians and the project is carried out.
28. The technical minister and chief engineer shall approve the reading notice in a clear position according to the corresponding oil meter oil pump matching calibration plan strips, so that it is easy to see at a glance. The prestressed tensioning is mainly based on the oil gauge reading and the elongation value is checked. When the elongation value exceeds ±6, stop tensioning and wait for the cause to be found before continuing to tension. The prestress is controlled by synchronizing at both ends, symmetrical left and right, and reaching the same load value at the same time. The out-synchronization rate is controlled within 10, the maximum unbalanced beam does not exceed one beam, and the tensioning sequence is carried out according to the requirements of the drawing. Three control measures are used for pre-stressing, namely stress, elongation value and load holding time, and the elongation at both ends is basically the same during the tensioning process. 7. Channel grouting process Channel grouting is a special process for box beam quality control. There are two grouting effects: one is to protect the prestressed ribs to avoid rust; the other is to effectively bond the prestressed ribs to the component concrete to control overloading. When the spacing and width of the cracks are reduced, the beam end anchor is reduced
29. The load condition, so the quality of the pore grout must be paid attention to. Grouting personnel are assigned as on-site monitoring personnel to strictly monitor the grouting equipment, grouting personnel, grouting materials, slurry flow, water discharge rate, vacuum degree, pressure value, and pressure holding time, and make corresponding monitoring records. 。 1. Things you must pay attention to when grouting: (1) Check the anchoring condition of pre-stressed stress before grouting. If there are any adverse phenomena, take measures immediately to deal with it before grouting; check various grouting equipment and test operation conditions Good, whether the slurry pipe is unobstructed, and it can only be used in normal conditions. (2) Before grouting for 24 hours, block all gaps at the anchor head. The blocking part is the gap between the contact surface of the anchor and the support pad and the gap between the steel strand between the anchor pad and the clip. (3) Grouting operation must be carried out under conditions where the ambient temperature is higher than +5. Otherwise, insulation measures or low-temperature construction methods will be adopted. Before the low-temperature season, all beams will be stored with high-pressure air.
30. Blow the water in the pipe to prevent freezing and cracking the beam body. (4) Clean the grouting holes of the anchor pad plate to ensure that the grouting channel is unobstructed. (5) Grouting specimens must be left in each beam during grouting construction, and cement slurry must be taken from the slurry outlet to make three sets of 40×40×160mm flexural specimens as 28-day standard specimens. 8. In order to prevent moisture and other harmful media from invading the beam body, the anchors and exposed steel strands are corroded. After the hole grouting work is completed and the inspection is passed, the beam body anchors are sealed in time. The anchor sealing concrete uses C50 dry hard compensation shrinkage concrete. The concrete raw materials except for the micro-expanding agent are all made of beam concrete materials. The appropriate amount of expansion agent is added, and the dosage is determined by the laboratory. At the same time, the water consumption is appropriately reduced and the water glue ratio is reduced. Make the concrete slump meet the construction requirements. Before sealing the anchor with the rear beam, the polyurethane waterproof coating is used to waterproof the anchor, the surface of the anchor pad and the exposed steel strand.
31. Before sealing the anchor, the anchor hole is chiseled first. The chiseling is carried out after the end mold is removed. It must be fully uniform and the chiseling area must not be less than 90%. 1. After the hair is chiseled, the anchor hole must be cleaned and clean with water before filling the concrete. 2. Before binding and sealing the anchor steel bars, remove the slurry on the surface of the anchor pad and the anchor mortar on the anchor ring. In order to strengthen the connection between the concrete after pouring and the beam body, the anchor hole at the end of the beam is chiseled and treated. Clean it, and clean up the floating slurry, ash and other debris in various places. 9. Steel accessories and reserved hole construction steel accessories refer to embedded parts for bridges, including support plates, anti-fall beam embedded plates, contact network support embedded plates, anchor pull wire foundation embedded plates, grounding terminals and cables Bridge climbing trough. Steel accessories are strictly entrusted to professional manufacturers to make them according to technical briefing and design drawing requirements. Their specifications and models meet the design requirements. Their performance is shown in the table 1 Table 1 Serial number inspection project technical standards 1 Size symbols of each part of the support plate
32. Comply with the design drawing requirements, the flatness of the support plate is 1 mm (edge height difference), the center distance deviation of the support bolts is 2 mm and the diagonal deviation is 3 mm. The sizes of the 2 anchor pad plates meet the design drawing requirements, the plate surface is flat, and the holes are The chamfers have no burrs, the grout holes are unobstructed, and the sizes of each part of the anti-falling beam stop meet the requirements of the design drawings. The weld is compact. 4 The sizes of each part of the contact mesh support meet the requirements of the design drawings. The bolts are vertical and ±1mm. The bolts are welded firmly with the embedded base plate. The seat plate, anti-fall beam bracket embedded plate, contact network support foundation embedded plate, anchor pull wire foundation embedded plate, grounding terminal and cable bridge climbing channel must be jointly displayed by the material equipment department and the safety and quality department. Inspection and random inspection and acceptance are carried out at a rate of 10%, and the supervision engineer will witness it. Acceptance must be carried out in accordance with the requirements of the drawings. The main acceptance items are shown in Table 1 above. Only after passing the qualification can it be put into production and use. 2. The installation position of the steel accessories is accurate and firm, and the exposed parts are rust-proof. 3. During the handling of steel accessories, they should be taken and placed gently. It is strictly forbidden to fall or overturn, so as not to deform and affect installation and use. The steel accessories entering the site should be stored in a fixed location, and the bottom should be padded more than 30cm. 4. The installation of embedded holes must be installed in accordance with the size and position of the drawings and reinforced firmly.

