Variability of Fresh and Hardened Properties of Paving-Concrete Mixtures

Fresh and hardened concrete properties from 24 paving projects in 23 states collected by the FHWA Mobile Concrete Trailer (MCT) were analyzed to assess overall variability associated with ‘paving-concrete’ production, including materials, process, sampling, and testing. The data reviewed was collected from paving projects over an eight-year period between 2011 and 2018 and represents a wide range of geographical locations, highway functional classification, materials,field conditions, sampling techniques, etc. Standard Deviations (SD) and Coefficient of Variations (COV) were used to assess and quantify variability of fresh and hardened concrete properties. The impact of the location of sampling (plant or grade), time of sampling (day versus night) and size of cylinders (6x12 versus 4x8) on variability of the data was also investigated. The following observations were developed: • The overall SD for typical paving mixtures for slump, unit weight and air content were 1/2", 1.6 pcf and 0.8% respectively. • The overall COV for typical paving mixtures for compressive strength (7, 28 or 56-days), SR (28 and 56 days) and RCPT were approximately 8%, 11%, and 17% respectively. • Unit weight and slump test data have the lowest and highest COV respectively. • CTE testing of concrete on a regular basis during production is not required since changes in CTE during typical concrete production are insignificant. • Except of slump measurements, there was statistically no significant difference in variation of test results between samples taken at the plant versus those on grade, night versus day and 6x12 and 4x8 cylinders (on compressive strength data).

  • Supplemental Notes:
    • This paper was sponsored by TRB committee AFH20 Standing Committee on Quality Assurance Management.
  • Corporate Authors:

    Transportation Research Board

    ,    
  • Authors:
    • Gudimettla, Jagan M
    • McDaniel, Lisa
    • Praul, Michael F
    • Grove, Jim
    • Conway, Robert
  • Conference:
  • Date: 2019

Language

  • English

Media Info

  • Media Type: Digital/other
  • Features: Figures; References; Tables;
  • Pagination: 23p

Subject/Index Terms

Filing Info

  • Accession Number: 01697364
  • Record Type: Publication
  • Report/Paper Numbers: 19-01497
  • Files: TRIS, TRB, ATRI
  • Created Date: Dec 7 2018 9:25AM