外约束作用对钢管内混凝土力学性能的影响  

Influences of External Constraints on the Mechanical Performances of In-Steel Tube Concrete

作　　者：成家定 朱哲 徐文 Cheng Jiading;Zhu Zhe;Xu Wen

机构地区：[1]中铁广州工程局集团桥梁工程有限公司,广东广州510800 [2]江苏苏博特新材料股份有限公司高性能土木工程材料国家重点实验室,江苏南京211103

出　　处：《江苏建材》2024年第1期36-39,共4页Jiangsu Building Materials

基　　金：江苏省自然科学基金资助项目(BK20221198)。

摘　　要：试验研究了掺入不同组成的钙镁复合膨胀剂对管内混凝土工作与力学性能的影响。结果表明,复合膨胀剂中氧化镁比例的增加会降低管内自密实混凝土流动性,而对间隙通过性和抗离析性影响不大。对于掺有复合膨胀剂的管内混凝土而言,相较于不受外约束作用的自由试件,其二维、三维外约束试件不同龄期抗压强度与弹性模量均显著增加。复合膨胀材料中氧化钙比例较高时,这一提升作用更加明显,可作为管内混凝土配合比设计时的安全储备。Experimental research was conducted to investigate the effect of the addition of calcium and magnesium oxides-based expansive agents with different compositions on the working and mechanical performances of the in-tube concrete.The results indicate that an increase in the proportion of magnesium oxide in the composite expansive agents reduces the flowability of the self-compacting in-tube concrete,while having little effects on the clearance permeability and segregation resistance.For the in-tube concrete prepared with composite expansive agents,compared to the free specimens without external constraints,the compressive strength and elastic modulus of the two-dimensional and three-dimensional external constraint specimens at different ages significantly increase.When the proportion of calcium oxide in composite expansive materials is high,this improvement effect is more obvious and can be used as a safety reserve for the design of the in-tube concrete mix proportions.

关 键 词：钢管混凝土拱桥 工作性能 力学性能 钙镁复合膨胀剂 外约束 

分 类 号：TU502.6[建筑科学—建筑技术科学]