This test study shows that there is a sound linear interrelation between the small core (7.

The research and discuss on the testing of strength of concrete in construction using small core gains more attention, because the development of building technology gives birth to many new problems in field testing work, which can t be solved by the existing standard related to these experiments.

? This paper investigates the effects of six factors such as diameter and height/diameter ratio of core specimen,particle size of coarse aggregate,strength grade,curing conditions and age on δ and fcu/fcor ratio,analyzes specifically the feasibility of the technology of concrete compressive strength testing with micro core specimen.

Application of small diameter core sample to the compressive strength identification of concrete structure;

Experimental study on compressive strength of high strength concrete core samples;

Some tests are done to verify the relation of rebound value of bottom surface,compressive strength value of core sample of bottom surface,compressive strength value of same condition test sample and compressive strength value of lateral core sample.

Several correction of core specimen and deduction of strength were compared through an engineering case.