摘要
隧道工程由于所处环境极其复杂恶劣,因此对于抗裂防渗有着极高的要求。隧道侧墙在采用分层浇筑时,由于旧混凝土层对新混凝土层存在强约束,容易出现裂缝。通过配合比设计优化出低热高抗裂混凝土,与普通混凝土形成梯度混凝土结构,降低外约束应力,提高侧墙抗裂性能。基于汕头某明挖隧道工程,监测4种模型段混凝土温度和体积变形情况,研究结构参数变化下梯度混凝土结构的温度效应与抗裂性能。研究结果表明,抗裂混凝土与普通混凝土温度变化历程基本相同,两种混凝土界面处最大温差为3.3℃,温度应力较小。适当结构参数下的梯度混凝土结构能达到全抗裂混凝土相同抗裂效果,有效减少裂缝出现,下层抗裂混凝土能够补偿收缩变形,发挥明显的控裂作用。梯度混凝土在分层浇筑长墙式构件控裂中具有广阔的应用前景。
Due to the extremely complex and harsh environment, tunnel engineering has high requirements for crack resistance and seepage prevention. When the side wall of the tunnel is poured in layers, cracks are prone to appear due to the strong restriction of the old concrete layer on the new concrete layer. By designing low-temperature rising and high crack resistance concrete to form a combined concrete structure with ordinary concrete, the external restraint stress wad reduced and the crack-resistant performance of the side wall was improved. Based on the open cut tunnel project in Shantou, this paper studied the temperature effect and crack resistance of combined concrete structure under the change of structural parameters by monitoring the temperature and volume deformation of concrete in four models. The research results show that the temperature change history of crack-resistant concrete was basically the same as that of ordinary concrete. The maximum temperature difference at the interface between the two concretes was 3.3℃, and the temperature stress was small. The combined concrete structure under appropriate structural parameters can achieve the same anti-cracking effect as the full anti-cracking concrete, effectively reducing the occurrence of cracks. The combined concrete structure has a broad application prospect in the crack control of long wall members cast in layers.
作者
余志鹏
张海松
于方
胡兴成
何贵
YU Zhipeng;ZHANG Haisong;YU Fang;HU Xingcheng;HE Gui(Key Laboratory of Harbor&Marine Structure Durability Technology of the Ministry of Communications,CCCC Forth Harbor Engineering Institute Co.,Ltd.,Guangzhou 510230,China;The Fifth Construction Co.,Ltd.of CCCC Fourth Harbor Engineering Co.,Ltd.,Fuzhou 350008,China)
出处
《建筑结构》
CSCD
北大核心
2022年第S02期2706-2711,共6页
Building Structure
关键词
大体积混凝土
开裂
组合结构
温度
变形
mass concrete
crack
composite structure
temperature
deformation
