Research On The Intensity Curved Line For Concrete Strength In Hohhot Area

Non-destructive concrete provides a most practical and reliable tool for the damage of concrete bonding detection and strength test after they completion. The existing methods most commonly used methods which is detected are Repercussion,Ultrasound and Ultrasonic-rebound combined method and so on. All these methods have been established many national norms and strength curve. However, due to various parts of concrete materials and techniques of construction, the error of the use of regulate formula in some area is very large. After the research and the analysis of data by this project, the error of the standardized ultrasound - rebound strength curve using in the Hohhot region is very large. The average of relative error is 28% or more.So it is necessary to establish the Intensity Curved Line in Hohhot area.The subject introduced the non-destructive testing experiments that is using repercussion,ultrasound and ultrasonic-rebound to evaluate the strength of concrete standardized-test of six types of strength grades (C20-C45) of 7day, 14day, 28day, 60day and 90days the five–age-period, then analysis these experimental data and fitting formulas. All these materials of the concrete are used common in Hohhot area,After a comparison of model the author made regression analysis on the tested data with mathematical statistical method. In addition,this thesis set up the testing strength curves of repercussion-strength, ultrasound-strength and ultrasonic -ultrasound formulas. Meanwhile,after the comparison of correlation coefficient and the accuracy error, we chose the power function as the repercussion-strength recommended formula, but linear function as the ultrasonic-rebound recommended formula in this area.The author use linear function power function, and exponential functions take a further study of ultrasonic–ultrasound method. By then, after the comparison of correlation coefficient and the accuracy error, we chose the power function as the ultrasonic–ultrasound recommended formula. Meanwhile, the author make a Comparative Study of region Strength Formula and recommended formula using the data which is collected from Post-production test block. By comparison, regional strength curve formula has a higher accuracy and better associated.