混凝土膨胀性对钢管/混凝土复合结构黏结强度的研究  

Study on the Influence of Expansion Properties of Concrete on Bonding Strength of Steel Tube and Concrete Interface

作　　者：闫风洁 王晓明 李辛庚 杜宝帅 樊志彬 YAN Fengjie;WANG Xiaoming;LI Xingeng;DU Baoshuai;FAN Zhibin(State Grid Shandong Electric Power Research Institute,Jinan 250003,China)

机构地区：[1]国网山东省电力公司电力科学研究院,山东济南250003

出　　处：《山东电力技术》2023年第5期61-65,共5页Shandong Electric Power

基　　金：国网山东省电力公司科技项目“35 kV及以下线路用薄壁钢管夹层混凝土电杆开发与应用”(52062622000B)。

摘　　要：针对硅酸盐混凝土易收缩开裂、与钢管界面黏结强度低以及钢管混凝土协同作用差的问题,研究改性硫氧镁混凝土的膨胀收缩性能,测试钢管/混凝土构件界面黏结强度。试验结果表明,改性硫氧镁混凝土具有微膨胀特性。轻烧氧化镁烧失量高,早期水化反应快,混凝土的体积膨胀率大;氧化镁烧失量低,早期水化反应慢,混凝土的体积膨胀率小。混凝土吸水后体积膨胀,失水后体积略有回缩,28 d保湿养护的混凝土整体稳定性较好。硫氧镁混凝土/钢管界面黏结强度约为硅酸盐混凝土/钢管界面黏结强度的20~27倍。与硅酸盐混凝土相比,硫氧镁混凝土应用于钢管混凝土复合结构具有明显优势。Aiming at the problems of easy shrinkage crack of silicate concrete,low bond strength with steel tube and poor synergistic effect of steel tube and concrete interface,the expansion properties of modified magnesium oxide cement concrete was studied,and the bond strength was tested.The results show that the modified magnesium oxide cement concrete show micro expansion performance.The higher the loss on ignition,the faster the early hydration reaction,the greater the volume expansion rate of concrete;the lower the loss on ignition,the slower the early hydration reaction,the smaller the volume expansion rate of concrete.The volume of concrete expands after absorbing water,and slightly shrinks after losing water,and the overall stability of concrete for 28 days is better.The bond strength of magnesium oxide cement concrete and steel pipe is about 20~27 times of that of silicate concrete.Compared with silicate concrete,magnesium oxide cement concrete has obvious advantages in steel tube concrete composite structure.

关 键 词：硫氧镁混凝土 体积膨胀率 烧失量 黏结强度 

分 类 号：TU528[建筑科学—建筑技术科学]