Implication of Statistical Quality Control of Portland Cement Concrete.

摘要

The research consists of the analysis of the process capability of portland cement concrete. The study was made on the basis of (1) a statistically designed experiment,from which parameters were obtained for various specification requirements of concrete;and (2) historical data,consisting of measurements obtained without random sampling. The statistically designed experiment gives information in regard to variances due to material,sampling and testing,for aggregates and portland cement concrete pavement. In addition,information in regard to skewness and kurtosis are of special interest,for studies in regard to the nature of distributions. Statistical parameters have been obtained for aggregates,on the basis of percent passing and percent retained. A study has been made of conformal index,which can be considered as a measure of the capability of construction process. A study was also made on the variations of coarse aggregate used in the concrete and as obtained from the pavement. The basis of the analysis is the Wilcoxon matched-pairs signed-ranks test. A comparison has also been made of normal project sampling and random sampling.