2011年2月第40卷
第3期
施工技
术
CONSTRUCTION TECHNOLOGY
青岛海湾大桥承台混凝土寒季养护技术
郭保林刘征涯’胡孝展”
（1.山东高速青岛公路有限公司，山东青岛266061;2.济南市工程质量与安全生产监督站，山东济南250013;
3.青岛路桥建设集团有限公司，山东青岛266032)
[摘要］青岛海湾大桥位于海水含盐度高且存在较严重自然冻融循环的胶州湾海域施工环境与服役环境都比较恶劣，非通航孔桥承台位于潮差区与浪溅区为了保证施工期及运营期的混凝土耐久性采用低水胶比、大接量矿物掺和料·适量引气的混凝土配制技术并利用外部围水设施实现海上干法施工·在冬季,为了降低施工期外界环境对混凝土性能的不利影响将围水设施顶部用帆布覆盖内部空间布置加热水箱承台侧面利用萄水型模板衬里提供不间断的保湿养护。自浇筑至14d养护龄期内承台侧面及顶面温度始终高于15℃相对湿度高于95%模板衬里内积蓄的水量高于混凝士养护所需要的水量采取该养护方案实现了承台混爱士的持续保温保湿养护保证了承台混凝土的各项性能健康发展，
[关键词】青岛海湾大桥：承台混凝士：养护技术：模板衬里
【中图分类号】U445
[文献标识码】A
[文章编号】1002-8498(2011) 03-0011-04
Cold Weather Curing of Cushion Cap Concrete in Qingdao Bay Bridge
Guo Baolin',Liu Zhengya’Hu Xiaozhan'
( 1. Shandong Hi-Speed Qingdao Expressaay Co. Jad. , Qingdao , Shandong266061 China;
2. Ji' nan Station of Construction Quality and Prodaction Safety Superrision , Ji' nan , Shandong250013 , China;
3. Qingdao Higheay & Bridge Construction Group Co. , Led. , Qingdao , Shandong266032 , China)
Abstract: The saline concentration of seawater is comparatively high and there are 50 times of freezing and thawing cycles in Kiaochow bay where the Qingdao Bay Bridge is located , moreover , the construction and service environment are very severe for reinforced concrete structure. The cushion caps of approach bridge are all among tidal zone and splash zone. Low water-cement-ratio , high volume mineral admixtures , and air entraining are the main technology to prepare cushion cap concrete. Some cofferdams are utilized to make the construction environment seawater free. In winter , the top of cofferdams are covered with canvas , the space between cushion cap and canvas are heated by several boiling water tanks , and the lateral surface of cushion cap are curing by controlled permeability formwork liner in order to reduce the disadvantage influenee of construction factor to concrete. During the first 14 days curing , the environment temperature around the cushion cap are kept above 15°C , and the RH is above 95% . The free water contained among controlled permeability formwork liner is more than the need of concrete curing. The curing program of cushion cap concrete utilized in Qingdao Bay Bridge under negative temperature can satisfy the need , and concrete performance develops well.
Key words: Qingdao Bay Bridge; cushion cap concrete; curing technology: controlled permeability formwork liner
1工程概况
青岛海湾大桥是我国北方冰冻海域首座特大型
桥梁工程是国家规划的青岛一兰州高速公路的起[收稿日期]2010-08-09
[基金项目］山东省交通运输厅和交通运输部联合攻关课题( 2009353337510)
[作者简介】郭保林山东高速青岛公路有限公司工程师青岛市崂
山区苗岭路29号山东高速大厦1807室
80990175 ,E-mail: gbl_jn@ 163. com 万方数据
266061，电话：(0532)
11
点段工程概算投资95.3亿元大桥由3座通航孔桥、非通航孔桥、陆上引桥及2座海上互通立交组成全长28.880km其中海上部分长27.079km。青岛海湾大桥所处的胶州湾海域海水含盐度较高（29.4%~32.9%e）存在较为严重的自然冻融循环（平均每年约有47~52次）每年12月中旬至2月中旬为冰冻期2010年初春，胶州湾海域大范围结冰（见图1)。