IMPLICATIONS OF STATISTICAL QUALITY CONTROL OF PORTLAND CEMENT CONCRETE
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. For historical data no analysis of variance has been done. 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 from aggregates, on the basis of percent passing and percent retained. Such analysis indicates the underlying causes of variance, and this aids in better control of aggregate production and utilization. A study has been made of conformal index, which can be considered as a measure of the capability of construction process, and indicates the deviations from the approved job-mix formula, unlike the standard deviation which gives the measure of the deviations from the mean of a population. A study has been made on the variations of coarse aggregate used in the concrete and an obtained from the pavement. The basis of analysis is the Wilcoxon matched-pairs signed-ranks test. A comparison has also been made of normal project sampling and random sampling. The statistical parameters obtained by the two methods of sampling on the same project shows the variations possible by different methods of project control.
- Prepared in cooperation with FHWA.
Phoenix, AZ United States 85007
- Gonsalves, GFD
- Eisenberg, J F
- Publication Date: 1975-1
- TRT Terms: Pore water pressures; Quality control; Randomization; Skewed structures; Statistical analysis
- Uncontrolled Terms: Skewness
- Subject Areas: Construction; Data and Information Technology; Highways; Materials;
- Accession Number: 00098972
- Record Type: Publication
- Source Agency: Federal Highway Administration
- Report/Paper Numbers: Report No. 7 Final Rpt.
- Contract Numbers: 1-12 (152)
- Files: TRIS, USDOT, STATEDOT
- Created Date: Oct 18 1975 12:00AM