A study was performed to gain a fundamental understanding of the traditional maturity method used to predict the in-place strength of concrete. Research was undertaken to answer two questions: (1) What are the quantitative effects of curing temperature on the compressive strength-maturity relation of concrete. (2) Is there an age beyond which temperature no longer affects the strength-maturity relation of concrete. To simplify testing, mortar cubes were used as specimens for compressive strength determinations. Penetration resistance measurements were performed to determine initial and final setting times. Phase I of the research addressed the first question and involved preparing and curing specimens at 5, 12, 23, 32, and 43 C. Phase II addressed the second question and involved curing specimens at 5 and 32 C for short periods, followed by additional curing at 23 C. It was found that initial set occurred at approximately the same maturity regardless of the curing temperature. A three-parameter hyperbolic equation was used to represent the strength-maturity relation. The parameters, determined by regression analysis, were found to vary systematically with curing temperature. Theoretical justification for the hyperbolic equation is presented and a key assumption in the maturity method is identified. The strength versus age data were also analyzed and a new concept, effective age, is suggested as a possible alternative for representing the combined effects of time and temperature on the compressive strength development of concrete.

  • Corporate Authors:

    National Bureau of Standards

    National Engineering Laboratory
    Gaithersburg, MD  United States  20760
  • Authors:
    • Carino, N J
  • Publication Date: 1981-3

Media Info

  • Pagination: 100 p.

Subject/Index Terms

Filing Info

  • Accession Number: 00337364
  • Record Type: Publication
  • Source Agency: National Technical Information Service
  • Report/Paper Numbers: NBSIR-81-2244
  • Files: TRIS
  • Created Date: Aug 15 1981 12:00AM