Modeling of compressive strength of concrete using pulse velocity values from a non-destructive testing of concrete

Abstract

In this research, ultrasonic pulse velocity (UPV) and crushing strength tests were carried out. Major factors which affect the strength of concrete such as concrete mix, aggregate size, and water-cement ratio were considered such that the model obtained could be used for the determination of strength of concrete elements made under different conditions. Three proposed models were calibrated using some of the data generated in the laboratory. The models were verified and compared with two similar existing models using the remaining data. The following statistical parameters were adopted for the comparison; the square of the coefficient of correlation (R2), the root mean square error (RMSE), and the average relative error (AVE). The proposed and existing models produced significant values of coefficient of correlations (R2) of 0.9833, 0.9645, 0.9895, 0.9822 and 0.9645. The first proposed model generated the highest value of R2 (0.9895), and least values of root mean square error and average relative error (1.35 and 4.95%) respectively, while the remaining models yielded an appreciable range of errors. The performance of the first proposed model shows that the correlation between the compressive strength of concrete and pulse velocity values is a logarithmic function. Key words: Non-destructive testing, ultrasonic pulse velocity, compressive strength, regression analysis, root mean square, average relative error.