Research On Non-destructive Testing Method And Artificial Intelligence Analyzing For Concrete Strength

With the development of the non-destructive testing techniques of concrete strength, the single testing strength means such as repercussion with hammer,ultrasound,embeded-pull-out, have widely been applied in the engineering inspection,and the relevant technical specification have also been issued and carried out.But with the improvement of the precision of testing strength,the single-target testing strength means cannot meet the engineering requirement that it appears especially important to set up testing strength curves with comprehensive methods.This paper introduced non-destructive testing experiments,that is,using ultrasound, repercussion and embeded-pull-out experiments to evaluate the strength for concrete standardized-tests of six types of strength grades ( C15, C20, C25, C30, C35, C40 )for 28 day,42day and 56days the three-age-period. The all materials used for tests are from Zhangjiakou area,which are widely applied in engineering projects. The related specimen concrete compressive strength experiments were performed in lab. On this base, the author made regression analysis on the tested data with mathematical statistical method.In addition , this thesis set up the testing strength curves of spring-back-ultrasound, ultrasound-pull-out , repercussion-pull-out , repercussion-ultrasound-pull-out comprehensive methods and relative formulas. Meanwhile,the author employed the results of the non-destructive testing of natural curing concrete tests to revise the regression formulas.By testing and verifying in some projects, the relativity of the comprehensive testing strength curves built in the thesis is better and the error is minor compared with common method. It is able to be promoted and applied in construction engineering and its surrounding area as the testing strength curves of the non-desstructive testing comprehensive methods of concrete strength.Artificial neural network (ANN) is a mathematical model of neural network of brain,and is a information handling system that simulate architecture and function of brain.ANN can realize complicated ligic operation and nonlinear relation,and it is very suitable for such problems that are difficult to be established,mathematical model but easy to be collected learning set.The non-destructive testing techniques of concrete strength is a very complicated prolem being influenced by many variable factors,and it is difficult to be expressed with a mathematical formula precisely.Therefore,the author put forword the research of the non-destructive testing techniques of concrete strength based on ANN.In order to make BP network more efficient,there are some optimized BP algorithms being put forword,including momentum Bp algorithms,variable learning rat BP algorithms and limited output of s-funcion algorithms.The mathematical model is set up by means of BP-artificial-neural-network technology based on considerable data from the experiment.Furthermore, corresponsive MATLAB program had been compiled to analyze the strength of concrete samples.