Diewald Fabian, Denolle Marine, Timothy Jithender J, Gehlen Christoph
Centre for Building Materials (cbm), Technical University of Munich, 81245, Munich, Germany.
Department of Earth and Space Sciences, University of Washington, Seattle, WA, 98195, USA.
Sci Rep. 2024 Aug 14;14(1):18861. doi: 10.1038/s41598-024-69564-4.
The microstructure of concrete can be affected by many factors, from non-destructive environmental factors through to destructive damage induced by transient stresses. Coda wave interferometry is a technique that is sensitive enough to detect weak changes within concrete by evaluating the ultrasonic signal perturbation compared to a reference state. As concrete microstructure is sensitive to many factors, it is important to separate their contributions to the observables. In this study, we characterize the relationships between the concrete elastic and inelastic properties, and temperature and relative humidity. We confirm previous theoretical studies that found a linear relationship between temperature changes and velocity variation of the ultrasonic waves for a given concrete mix, and provide scaling factors per Kelvin for multiple settings. We also confirm an anti-correlation with relative humidity using long-term conditioning. Furthermore, we explore beyond the existing studies to establish the relationship linking humidity and temperature changes to ultrasonic wave attenuation.
混凝土的微观结构会受到许多因素的影响，从非破坏性的环境因素到由瞬态应力引起的破坏性损伤。尾波干涉测量法是一种技术，它足够灵敏，能够通过评估与参考状态相比的超声信号扰动来检测混凝土内部的微弱变化。由于混凝土微观结构对许多因素敏感，因此区分它们对可观测值的贡献很重要。在本研究中，我们表征了混凝土弹性和非弹性性质与温度和相对湿度之间的关系。我们证实了先前的理论研究，即在给定的混凝土混合料中，温度变化与超声波速度变化之间存在线性关系，并针对多种情况给出了每开尔文的比例因子。我们还通过长期调节证实了与相对湿度的反相关性。此外，我们超越现有研究，建立了将湿度和温度变化与超声波衰减联系起来的关系。
