Sustainable Concrete Columns with GGBS and Industrial Sand: A Comparative Study on Destructive and Nondestructive Tests on Damaged Columns Strengthened with GFRP Jacketing

Table 2

Ultrasonic pulse velocity test results.

Sample ID	1st crack occurrence velocity (km/s)
	Before wrapping	After wrapping
C	3.53	4.12
C	3.49	4.08
GG15	3.79	4.26
GG15	3.82	4.35
GG25	3.88	4.56
GG25	3.86	4.48
GG35	3.98	4.51
GG35	4.01	4.63