碾压混凝土坝分层浇筑施工风险及其控制措施研究  

Research on construction risks and control measures of layered pouring of RCC dam

作　　者：蒋荣清 刘伟佳 牛旭婧 谭尧升 刘春风 李庆斌[2] 胡昱[2] JIANG Rongqing;LIU Weijia;NIU Xujing;TAN Yaosheng;LIU Chunfeng;LI Qingbin;HU Yu(State Power Investment Corporation Co.,Ltd.,Beijing 100050,China;State Key Laboratory of Hydroscience and Engineering,Tsinghua University,Beijing 100084,China;China Three Gorges Construction Engineering Corporation,Beijing 100000,China)

机构地区：[1]国家电力投资集团有限公司,北京100050 [2]清华大学水沙科学与水利水电工程国家重点实验室,北京100084 [3]中国三峡建工(集团)有限公司,北京100000

出　　处：《混凝土》2023年第4期176-179,共4页Concrete

基　　金：国家自然科学基金(51979145,51839007);中国长江三峡集团公司科研项目(BHT/0809,WDD/0458)。

摘　　要：坝区高温低湿、大风等极端天气会使分层浇筑混凝土层间结合性能发生劣化。通过测定极端天气环境(如:高温低湿、大风)下混凝土的层面状态(含水量、贯入阻力)和层间劈裂抗拉强度,对3种施工措施(如表面不处理、覆盖保温被和界面凹槽)进行了研究。结果表明:碾压混凝土坝在极端环境下浇筑存在施工风险。在高温低湿条件下覆盖保温被并不能有效避免层间结合质量的下降,界面凹槽可以小幅度地提高坯层间结合强度;在大风条件下坯层表面覆盖保温被及采用界面凹槽处理是比较可行的措施,可以保证坯层间结合质量满足要求。在大风条件下覆盖保温被,一方面防止了水分的散失,另一方面延缓了混凝土的凝结速率,使得层间劈拉强度得到保证。Extreme weather such as high temperature and low humidity,strong wind will deteriorate the interlayer bonding performance of layered concrete.Three construction measures(such as surface untreatment,covering insulation blanket and interface groove)were studied by determining the layer state(water content,penetration resistance)and interlayer splitting tensile strength of concrete under extreme weather conditions(such as high temperature,low humidity).The results show that there are construction risks in construction of RCC dams in extreme environments.Covering the insulation blanket under high temperature and low humidity can not effectively avoid the deterioration of interlayer bonding quality.The interlayer bonding strength of concrete can be improved by taking interface groove measures.It is feasible to cover the surface of layer with insulation blanket and adopt interface groove treatment under strong wind conditions,which can ensure that the interlayer bonding quality meets the requirements.Covering insulation blanketin windy conditions prevents water loss.In addition,the setting rate of concrete was retarded to ensure the interlayer splitting tensile strength.

关 键 词：低热水泥 碾压混凝土 分层浇筑 表层含水量 贯入阻力 劈裂抗拉强度 施工风险 

分 类 号：TU528.01[建筑科学—建筑技术科学]