Request for Proposal (RFP)
Posted July 23, 2002

IPRF Project FAA -01-G-002-4

Strength Measurements using Maturity for Portland Cement
Concrete Pavement Construction at Airfields


The maturity method for measuring concrete strength produces an estimate of strength based on the actual temperature history experienced by the concrete in place. As such, the maturity method attempts to address the differing hydration rates experienced by test specimens compared to the concrete in place. The maturity method requires development of a strength-maturity relationship that is specific to the mixture. Application of maturity has been increasing and certain state agencies have made it a standard test for determining when to open concrete highway pavement to public traffic. Use of maturity in the airport environment has been limited. Potential benefits to the airfield concrete pavement industry includes:

  • Decreasing time to open critical areas to traffic (such as intersections, runway ends and full panel replacement),
  • Shortening the time between staged paving operations,
  • Improving joint sawing operations,
  • Reducing the number of strength tests, and
  • Improving reliability of acceptance techniques through testing in-place material.

Conventional use of maturity testing requires a maturity index value (also called a time-temperature factor, or TTF) or an "equivalent age" value to be read from a maturity meter and/or calculated from a time-temperature profile. This maturity index value (or equivalent age) must then be compared to the established strength-maturity relationship curve to convert it to a strength value. Technology is on the edge of being able to automate this conversion and provide information in units that a contractor or engineer can understand in real time.

The primary limitation of conventional maturity measurement stems from the need to convert the temperature readings from embedded thermocouples, or the degree-hours (i.e. TTF) units from maturity devices, to strength values.


The objective of the research will be to demonstrate a non-complex solution for measuring the strength of airfield pavements in real time using concrete maturity theory. The field-demonstration(s) shall be made on at least one site in the airport environment. The participation of a paving contractor is required for this research project. As part of the proposal and inherent to the research objective, the investigator shall prepare and describe a research plan outlining:

  • The airport application test site(s), including documents from the airport sponsor and/or operator and contractors
  • The concrete mixture components, proportions and test requirements
  • The planned location of maturity probes
  • Comparison (destructive) test regimes, if proposed
  • Properties of the maturity testing equipment, particularly with regard to field durability, ease of use, accuracy, and data logging capability. This should include statements prepared by the contractor and the quality control laboratory.


The deliverables are three documents:

1. The research team will provide a test plan for review and comment by the project Technical Panel. That test plan will incorporate panel comments prior to executing the field portion of the research.

2. The investigator shall provide a final report, documenting all of the testing techniques, testing regimen used for comparative analysis, materials, mixtures, equipment, results and methods used in the investigation. The submittal shall include two copies of the final report manuscript along with an electronic copy of the report, electronic artwork, photos, etc. The electronic copy of the report must be compatible with industry recognized desktop computer publication software (either Microsoft Word or Adobe Acrobat).

3. The investigator will provide a short Executive Summary report separate from the final report. The Executive Summary report should be between 2 and 8 pages in length, include summary charts, graphics, etc that are necessary to report the results of the research project. The submittal shall include two copies of the Executive Summary report along with an electronic copy of the report, electronic artwork, photos, etc. The electronic copy of the report must be compatible with industry recognized desktop computer publication software (either Microsoft Word or Adobe Acrobat).


The technical panel expects to see maturity equipment with advanced technology. Proposals should describe any advanced features of the equipment with regard to eliminating data conversion, linking to central monitoring computers, low-cost implementation, unit recycling, etc. Due to the expected short duration of this project, the investigator will be responsible for coordinating the progress of the work by the utilization of conference calls with the technical panel to review the progress of the research effort. The investigator shall record minutes of the calls and distribute the written minutes and a written progress report to the panel members within 2 days of the calls. The minutes and report will each be two pages maximum in a format to be specified.


Persons preparing proposals are urged to review the following documents to be sure that there is a full understanding of IPRF procedures and requirements. Proposals must be prepared in the format specified in the instruction documents. The documents needed to prepare the proposal include:

FUNDS AVAILABLE: Not to Exceed $47,000

CONTRACT TIME: Not to exceed 6 Months

PROJECT DIRECTOR: Gerald F. Voigt, P.E., (847) 966-2272,


PROPOSAL DUE DATE: August 23, 2002 not later than 4:00 P.M. (EDST)


Deliver six (6) copies of your proposal to:

Mr. Gerald Voigt, Project Director
5420 Old Orchard Road, Suite 100
Skokie, IL 60077

Return to IPRF Airfields Research