Title: Early-age concrete strain error detecting method under continuous temperature change
Authors: Yunxia Li; Qi Ding; Jiahai Liu; Fang Yu
Addresses: Department of Railway Engineering and Civil Engineering, Shandong Polytechnic, Jinan 250104, China ' Jinan Rail Transit Group Co., Ltd., Jinan, China, 250101, China ' Jinan Rail Transit Group Co., Ltd., Jinan, China, 250101, China ' College of Civil Engineering, Hunan City University, Yiyang Hunan, 413000 China
Abstract: The stiffness of concrete members and the free energy of material degenerate under the continuous temperature change, and the strain error exists. In order to solve the above mentioned problems, Early-age concrete strain error detecting method under continuous temperature change is proposed. Through accurate measurement of concrete strain error, the nonlinear creep model of early age concrete structure under continuous temperature change is deduced. The coupling relationship between material stress and creep is quantitatively analysed to improve the strength of concrete. A method for detecting early age concrete strain error under continuous temperature change based on concrete splitting tensile strength microscopic analysis and low cycle fatigue test is proposed. The nonlinear relationship model of concrete strain amplitude and the number of fatigue cycles under continuous temperature is established. Considering constraint parameters of concrete such as buckling, fatigue and strength, concrete constitutive model is constructed. Test results show that the method used to detect early age concrete strain error under continuous temperature change has better reliability and strain error test results and experimental results are in good consistency.
Keywords: continuous temperature variation; early age concrete; splitting tensile strength; strain; fatigue; strength.
International Journal of Microstructure and Materials Properties, 2018 Vol.13 No.3/4, pp.135 - 146
Received: 22 Aug 2017
Accepted: 14 Mar 2018
Published online: 13 Nov 2018 *