Based on the analysis of data that have been gotten from test on numerous concrete samples,the regression formulas of rebound method and ultrasonic-rebound method of commercial concrete strength were obtained.

The same element was examined by rebound method and ultrasonic rebound synthetic method respectively.

On the cumulative frequency of the estimated concrete strength for single concrete structural member in the ultrasonic-rebound combined method;

Therefore,the genetic algorithms can be taken as the effective tool in the process of constructing concrete ultrasonic-rebound strength curve for ultrasonic-rebound combined method.

Using the local raw mterials such as aggregate and sand in Kaifeng,dozens of specimens of concrete chosen from both the pumped and the non-pumped with different grades of strength and in different age groups were made and tested by ultrasonic-rebound combined method followed by load bearing capacity test until the specimens destroyed completely.

Strength test on concrete lining in highway tunnel based on synthetic method of ultrasonic rebound;

Difference of stress distribution,maintaining condition and long age between the concrete lining of road tunnel and permitted qualification of synthetic method of ultrasonic rebound are analyzed,and a principle is put forward that the lining strength should be deduced according to the classification of the lining of road tunnel based on the grade of surrounding rock.

The limits of Synthetic method of ultrasonic rebound applied to the strength test of concrete lining of highway tunnel are analyzed,and a principle is put forward that the lining strength should be determined on the basis of the classification of surrounding rock.