Research On Reliability Test Method For Compressive Strength Of Concrete Cube

In the field of civil engineering,concrete,as a widely used building material,has good compressive performance.In actual construction,the management and inspection of construction quality is an extremely important part of the project.Many embankments,channels,and small and medium-sized water conservancy and farmland projects are difficult to ensure construction quality due to poor construction conditions and high construction difficulty.Concrete strength can be an important indicator for quality control.Due to the small scale of some small-scale agricultural water conservancy projects,there are few samples available for inspection.At this time,evaluating its quality using classical methods cannot accurately represent the parent material information.Based on the above background,this article focused on the reliability test of uniaxial compressive strength of C30 concrete,and specifically studied the classical statistical methods based on two types of risks and the reliability statistical test methods under Bayesian statistical methods.Through the reliability statistical test design method based on two types of risks,the classical statistical method under three common distributions(binomial distribution,exponential distribution,normal distribution)and the reliability statistical identification test method under Bayesian method were given.Comparative analysis of the risks of both Bayesian method reliability identification test plans and classical method reliability identification test plans with sample sizes ranging from 1 to 200 under Bayesian prior distribution,population variance,and test limits showed that,under the premise that the prior mean is greater than the test limit,the production side risk under the Bayesian scheme is always lower than that under the classical scheme.However,when the sample size is less than or equal to 20,the user risk under the Bayesian scheme is higher than that under the classical scheme.When the sample size is greater than 20,the user risk under the Bayesian scheme is lower than that under the classical scheme.When the overall variance of the normal distribution is known,this paper considers the impact of the mean and variance in the conjugate prior distribution of the overall mean on the Bayesian reliability sampling scheme respectively.The results show,the greater the prior mean is than the test limit required by the test,the higher the risk of the manufacturer under the Bayesian reliability appraisal test scheme,and the lower the risk of the user.The closer the prior distribution variance is to the overall variance,the lower the risk of both parties under the Bayesian reliability identification test scheme.This article used the reliability analysis method of Bayesian method to collect prior information on the mean uniaxial compressive strength of C30 concrete under the same mix ratio and curing conditions.The distribution of the collected prior information was fitted using the Kolmogorov test method to determine the prior distribution of the mean uniaxial compressive strength of C30 concrete.After obtaining the prior distribution,according to the characteristics that the uniaxial compressive strength of concrete generally obeys the normal distribution,under the condition that the uniaxial compressive strength of C30 concrete obeys the normal distribution and the variance is known,the conjugate prior distribution was selected as the prior distribution,and the Bayesian reliability evaluation test scheme based on the mean value of C30 concrete strength under the risk constraints of both parties was given.After the test,I evaluated the experimental batch of C30 concrete based on Bayesian statistical inference theory.After the field test,the C30 concrete of the test batch was evaluated according to Bayes and classical statistical inference theory,and the confidence interval length of Bayes method is smaller under the condition of the same reliability.Under the condition of the same set(acceptable)confidence interval,the reliability of Bayes method is higher,which indicates that the application of Bayes in reliability statistical test can estimate the population information more accurately.