Abstract:
This research is based on the 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. Ten samples of ordinary Portland cement obtained from ten
different sources were used to prepare thirty (30) specimens of cement mortar. Water/cement
ratio, sand content, method of specimen preparation, curing conditions were kept constant
throughout the experiment. Portable Ultrasonic Nondestructive Digital Indicating Tester with
a transducer of 54 kHz frequency was used to measure ultrasonic pulse velocity.
Initially ultrasonic pulse velocity of ten samples of cement mortar was measured and
compressive strength of same specimens was determined. Then the behavior of ultrasonic
pulse velocity with cement hydration was studied. Graphs between ultrasonic pulse velocity
and compressive strength of cement mortar, and graphs between ultrasonic pulse velocity
and curing time were plotted for ten samples. Correlations obtained from above experiments
were used to predict 28 days compressive strength of cement mortar within 02 days.
In this research it was found that the relationship between ultrasonic pulse velocity and
compressive strength was linear and Lime Saturation Factor of cement also 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 and that equation was verified using another five (05) cement
mortar samples.
