Water Content Diagnostics of Concrete Using Nonlinear Acoustics Means
It is known that water or moisture affects the concrete strength seriously. In this paper, the concrete strength is evaluated from the relationship between water content and the acoustic nonlinearity parameter. To measure the influence of water content, a test piece was put in an oven to change the amount of water. Acoustical parameters were measured while one kilogram of water was vaporized until the weight of the concrete was no longer changed. All results were measured at the first natural frequencies of the concrete rod with one acoustically rigid boundary and one acoustically compliant boundary. The results of measurements were made on nonlinear parameters r1 and r2 as a function of the water content in concrete. The result of r1≠r2 reflects the asymmetry of the compressive and expansion processes, and the phenomena of r1 and r2 changing reversely with water content also proved the difference of these two processes. Moreover, nonlinear parameter and frequency shift are more sensitive to the damage of the concrete than the linear parameters obtained by the traditional acoustics methods. So, this method based on nonlinear acoustics maybe provides a better means of the Non Destructive Testing (NDT) of concrete.
Concrete NDT nonlinear parameters
Dao ZHOU Xiaozhou LIU Xiufen GONG Li MA
Key Laboratory of Modern Acoustics, Ministry of Education, Institute of Acoustics, Nanjing Universit Institute of Acoustics, Chinese of Academy of China, 100080, China
国际会议
第十七届世界无损检测会议(17th World Conference on Nondestructive Testing)
上海
英文
1564-1569
2008-10-25（万方平台首次上网日期，不代表论文的发表时间）