Experimental Study on the Compressive Strength of Big Mobility Concrete with Nondestructive Testing Method

Table 2

Rebound curve for concrete strength measurement and error.

Regress model	Function expression	Correlative coefficient	Mean relative error (%)	Relative standard error (%)
Exponential function (1)	𝑓^𝑐𝑐𝑢=6.004665×𝑒^(0.047526×𝑅𝑚−0.0177×𝑑𝑚)	0.824	12.43	15.33
Exponential function (2)	𝑓^𝑐𝑐𝑢=278.2863×𝑒^(−77.233/𝑅𝑚+0.00009/𝑑𝑚)	0.850	11.88	14.7
Logarithm function	𝑓^𝑐𝑐𝑢=−235.71+75.30×ln(𝑅𝑚)−0.53812×ln(𝑑𝑚)	0.868	11.21	16.88
Power function	𝑓^𝑐𝑐𝑢=0.0284776×𝑅𝑚^1.96297×𝑑𝑚^−0.01553	0.850	11.17	14.05
Power exponential function	𝑓^𝑐𝑐𝑢=6.00468×1.048672^𝑅𝑚×𝑒^−0.0177×𝑑𝑚	0.824	12.43	15.33
Complex-exponential function	𝑓^𝑐𝑐𝑢=0.032509×𝑅𝑚^1.94172×10^−0.00789×𝑑𝑚	0.852	11.04	13.75