Research Evaluation Method On Random Test Result Of Concrete Strength

There exists certain dispersivity and uncertainty in the nondestructive test result of concrete strength. In the actual project, it is the problem to be solved urgently how to utilize these indefinite test result to draw evaluation conclusion with reasonable and relative determinate.When evaluating structural strength by utilizing test result, the evaluation methods are different because test purposes and engineering importance are different. The different evaluation method may provide different qualification and unqualification, and the test cost is different too. For the main component of the major structure, the evaluation conclusion of qualification to be drawn must be high probability because disastrous situation might appear if it fails. For expensive engineering structure or component, the evaluation conclusion of unqualification to be drawn must be also high probability because the serious economic loss might appear if it is judged falsely. For some specific engineering structure in the specific situation, sometimes it needs to use the way which not confirmation means negative or not negative means confirmation.Through studying each test evaluation method thoroughly, the basic idea and method of evaluation for the random test result are presented systematically, namely strong-strong evaluation,weak- strong evaluation,extreme weak - strong evaluation,strong - weak evaluation, strong - extreme weak evaluation. Directing to each evaluation method, the applicable scope is discussed also. The calculating equation of strength evaluation are established when the characteristic value is normal population percentile and indirect test measure. And two kinds of method are presented to reduce length of undetermined interval.This idea and method of evaluation applied in actual engineering may present quantitative evaluation result and increase reliability. This method could applie to not only the evaluation of test result of concrete strength but also other fields.