Degradation of Dynamic Elastic Modulus of Concrete under Periodic Temperature-Humidity Action

Depeng Chen,Liang Zhao,Jiajia Zou,Chunlin Liu,Shidai Xu,Tengfei Xiang

doi:10.3390/ma13030611

Depeng Chen, Liang Zhao + Show 4 more

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https://doi.org/10.3390/ma13030611

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Journal: Materials	Publication Date: Jan 30, 2020
Citations: 10	License type: CC BY 4.0

Affiliation: Southeast University, Anhui University of Technology

Abstract

Cracks caused by environmental temperature and humidity variation are generally considered one of the most important factors causing durability deterioration of concrete structures. The seasonal or daily variation of ambient temperature and humidity can be considered periodic. The dynamic modulus of elasticity is an important parameter used to evaluate the performance of structural concrete under periodic loads. Hence, in this paper, the dynamic elastic modulus test of concrete under simulating periodic temperature-humidity variation is carried out according to monthly meteorological data of representative areas (Nanjing, China). The dynamic elastic modulus attenuation pattern and a dynamic elastic modulus degradation model of concrete under periodic temperature-humidity are investigated. The test results show that the dynamic elastic modulus of concrete decreases and tends to be stable under the action of periodic temperature-humidity. Comparative analysis shows that the two-parameter dynamic elastic modulus degradation model is more suitable for describing the dynamic elastic modulus attenuation pattern of concrete under periodic temperature-humidity action than the single-parameter one.

Highlights

For most structures, durability is an important performance and a decisive factor which influences service performance during the whole life cycle [1,2]
The resonant frequency and weight of different specimens were measured before the test and after each cycle of periodic temperature-humidity in the dynamic elastic modulus test of concrete with the strength grades C20, C30, and C40
9651.33 loss and relative dynamic modulus of elasticity of concrete specimens under periodic temperature and humidity; the research results of concrete damage under freeze‐thaw cycles in the study of concrete frost resistance were used in comparative analysis in this paper

Summary

Introduction

Durability is an important performance and a decisive factor which influences service performance during the whole life cycle [1,2]. Environmental impact is generally considered one of the most important factors causing durability deterioration of concrete structures and the performance of concrete under ambient conditions has attracted more and more attention in recent decades [3,4]. It is recognized that the durability of concrete structures is strongly influenced by cracks caused by external loading and other environmentally-induced stresses, that is, the volume stability of concrete. When the stress induced by load stress and temperature-humidity stress exceeds the tensile strength, the concrete will crack and eventually lead to more serious durability deterioration such as carbonization, chloride ion penetration, internal steel corrosion, and so on [6,7]. Environmentally-induced stresses mainly result from temperature and humidity variation, which are the most common ambient actions and change dramatically during the lifetime of a structure [1]

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