Deterioration of dynamic mechanical property of concrete with mineral admixtures under fatigue loading

• Published in: Science China. Technological sciences Vol. 57; no. 10; pp. 1909 - 1916
• Main Authors: Ma, KunLin, Xie, YouJun, Long, GuangCheng, Tan, WenYong
• Format: Journal Article
• Language: English
• Published: Heidelberg Science China Press 01.10.2014
• Subjects: Engineering; 动态剪切模量; 动态力学性能; 动态弹性模量; 动态机械性能; 恶化; 疲劳载荷; 矿物掺合料; 高混凝土; concrete; mineral admixtures; dynamic mechanical property; deterioration; fatigue loading
• ISSN: 1674-7321; 1869-1900
• DOI: 10.1007/s11431-014-5632-z

The dynamic mechanical property of concrete is one of the key parameters, which greatly influences durability of infrastructures subjected to continuous heavy loading, such as girder and track slab of high-speed railway foundation structure. This paper reports serials of experiments designed to investigate the deterioration of dynamic mechanical properties of different concretes under fatigue loading condition. Four parameters including relative dynamic elastic modulus（RDEM）, relative dynamic shear modulus（RDSM）, relative compressive strength（RCS） and water absorption（WA） of concrete were evaluated to assess the dynamic properties and microstructures of concretes. Results show that the fatigue stress levels and fatigue cycle durations significantly influence the dynamic mechanical properties of concrete including dynamic elastic modulus and dynamic shear modulus. Addition of proper mineral admixture can improve the dynamic mechanical characteristics of concrete and increase its resistance against the fatigue loading effect. Keeping the amount of mineral admixture in concrete constant, its dynamic mechanical property with fly ash is lower than that with fly ash and silica fume. The water absorption in concrete, which is an indirect parameter reflecting capillary porosity, increases evidently after bearing fatigue-loading. There is a close correlation between the deterioration of dynamic mechanical property and the increasing of water absorption of concrete. This indicates that the damage of microstructure of concrete subjected to fatigue loading is the indispensable reason for the decay of its dynamic mechanical performance.