Effect of Sample Size and Methods on Percent within Limits for Quality Control and Assurance

The construction quality of a lot is often measured by collecting and testing a few samples. The statistics of an acceptance quality characteristic (AQC) of the lot determined based on the samples is used to make an inference on the overall construction quality. The most commonly used quality measure to quantify the quality is percent within limits (PWL). For performance-related construction specification, the PWL value of a lot is related to its expected future performance. While a contractor is paid an incentive if the measured quality is better than acceptable quality limits (AQL), the contractor may be penalized if the measured quality is less than AQL. Therefore, the accuracy of PWL estimation is important to minimize over/under payment to the contractor for the produced quality. In this paper, an effort has been made to determine the effect of sampling plans and sizes on the PWL estimation of a lot. Air void contents after construction were used as the AQC with two sided specification limits. Different sampling plans include: (1) random sampling with replacement, (2) stratified sampling, and (3) random sampling without replacement. For each sampling plan, samples of sizes 3, 5, 10, and 20 were used to evaluate the combination (i.e., sampling plan and sample size) for estimating PWL. The estimated PWL values were compared with the true PWL of the lot. The results show that stratified sampling plan represents the true construction quality of a lot better for lower sample sizes.

• Record URL:
  • https://doi.org/10.1061/9780784480922.012
• Availability:
  • Find a library where document is available. Order URL: http://worldcat.org/isbn/9780784480922
• Supplemental Notes:
  • © 2017 American Society of Civil Engineers.
• Corporate Authors:

  American Society of Civil Engineers

  New York, New York  United States 
• Authors:
  • Haider, Syed Waqar
  • Musunuru, Gopikrishna
  • Chatti, Karim
• Conference:
  • International Conference on Highway Pavements and Airfield Technology 2017
  • Location: Philadelphia Pennsylvania, United States
  • Date: 2017-8-27 to 2017-8-30
• Publication Date: 2017-8

Language

• English

Media Info

• Media Type: Web
• Pagination: pp 134-144
• Monograph Title: Airfield and Highway Pavements 2017: Design, Construction, Evaluation, and Management of Pavements

Subject/Index Terms

• TRT Terms: Air voids; Paving; Quality assurance; Quality control; Random sampling; Sampling
• Uncontrolled Terms: Percent within limits; Sample sizes; Stratified sampling method
• Subject Areas: Construction; Highways; Pavements;

Filing Info

• Accession Number: 01685217
• Record Type: Publication
• ISBN: 9780784480922
• Files: TRIS, ASCE
• Created Date: Nov 12 2018 11:17AM