Experimental investigation on dynamic mechanical characteristics and microstructure of steam-cured concrete

• Published in: Science China. Technological sciences Vol. 57; no. 10; pp. 1902 - 1908
• Main Authors: Long, GuangCheng, Wang, Meng, Xie, YouJun, Ma, KunLin
• Format: Journal Article
• Language: English
• Published: Heidelberg Science China Press 01.10.2014
• Subjects: Concretes; Damping; Dynamics; Engineering; Foundations; High speed; Microstructure; Railroads; Railway engineering; Storage modulus; 动态力学性能; 动态弹性模量; 实验; 微观结构; 机械特性; 混凝土预制件; 蒸养混凝土; 蒸汽养护; dynamic elastic modulus; steam-cured concrete; microstructure; shear modulus; damping ratio
• ISSN: 1674-7321; 1869-1900
• DOI: 10.1007/s11431-014-5635-9

Steam-cured concrete is widely used to manufacture prefabricated units of high-speed railway foundation structure such as girder and track slab. The dynamic mechanical property of steam-cured concrete is one of the key properties affecting service performance of high-speed railway foundation structure. In the present paper, serial macro/micro-experiments were carried out to investigate the dynamic elastic modulus, shear modulus, damping ratio, and microstructure of steam-cured concrete. The relationships between compositions, curing regime, microstructure, and dynamic properties of steam-cured concrete as well as the corresponding mechanisms were discussed. The results indicate that steam-cured concrete in early age has a larger dynamic elastic modulus and shear modulus as well as a smaller damping ratio compared with standard-cured concrete. On the contrary, at a later age a slightly smaller dynamic elastic modulus and a larger damping ratio of steam-cured concrete are observed. Addition of mineral admixture results in a bit lower dynamic elastic modulus and damping ratio of concrete than that of the control specimen without mineral admixtures. The achievements can provide some fundamental suggestions for materials parameters selection during structural design of steam-cured concrete precast element.