The Research On The Test Of Structural Concrete Using Small Core

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. As to the concrete element with high-strength, thin shell and crowed concrete reinforced bar in high-rise structure and highway project, in order to minimize the impairment to structural element, the small core in size ofΦ70mm×70mm,Φ50mm×50mm has been employed in this paper to estimate the strength of structural concrete. The main problems studied in the paper are as follows, applying contrast experiment and mathematical theory statistics methods.1. The development, merits and drawbacks of several nondestructive examination methods were introduced. And the feasibility and rationality of strength testing of structural concrete employing small core in size ofΦ70mm×70mm,Φ50mm×50mm were studied. The factors affecting experiment results were analysed, the coefficient of correction and corresponding constraint equation for the estimation of strength of structural concrete.2. The preparation of experiment, scheme, procedure, process of analysis and calculation were expressed clearly.3. The accuracy of testing method using these two model has been compared, and a study was made to get a proper sampling span.4. A exploratory experiment was put into practice to find the maximum size of aggregate in concrete being suitable for testing employing small core in size ofΦ70mm×70mm,Φ50mm×50mm.5. The factors affecting testing results such as the state of concrete specimen being loading-on, low grade concrete, the quantity of reinforced bar were analyzed.