Non-destructive evaluation of strength gain of ordinary portland cement mortar by ultrasonic pulse velocity method

Abstract

This paper presents results of the study of ultrasonic pulse velocity and compressive strength of ordinary Portland cement mortar. Objectives of this study are to determine correlations between ultrasonic pulse velocity and compressive strength of cement mortar and to predict strength of cement mortar at 28 days within 02 days using ultrasonic pulse velocity of cement mortar. Water/cement ratio, sand content, method of specimen preparation, curing media and curing temperature were kept constant throughout the experiment. Portable Ultrasonic Nondestructive Digital Indicating Tester with transducers of 54 kHz frequency was used to measure ultrasonic pulse velocity. In this research it was found that the relationship between ultrasonic pulse velocity and compressive strength was linear and Lime Saturation Factor (LSF) of cement has an influence on this relationship. Further it was seen that, with the increase of curing period ultrasonic pulse velocity of all samples increased. At the end it was possible to obtain an equation that can predict the cement strength at 28 days within 02 days and that equation was verified using another five (05) cement mortar samples. Correlations obtained in this research is recommended to used for cement mortars prepared and tested at laboratories at a temperature of 271 0C.