CHECKING THE QUALITY AND INTEGRITY OF CONCRETE IN PAVEMENTS

This article describes two on-site tests for checking the quality and integrity of concrete in pavements. The first is a method for the measurement of tensile strength under uniaxial tension (the ACT test). In this a concrete cylinder is subjected to pressure by nitrogen gas through its bare curved surface, thus inducing a cleavage fracture generally orthogonal to the long axis. The fracture pressure is read directly from the pressure gauge on the gas pipeline, and the result is the axi-symmetric compression/tension (ACT) strength. This is taken to be a measure of the tensile strength. Strength monitored in this way shows very good correlation with results obtained from standard strength tests on water cured specimens. Methods are proposed for the use of the test in routine control testing. No end capping is required and the concrete can be tested after one day. The second method is the portable non destructive relative permeability (RP) test. In this test, a small funnel is glued to the surface of the concrete core specimen in order to monitor the pressure decay with time of nitrogen gas from a 1.6 L reservoir (at 10 bar) through the funnel and into the concrete. A pressure transducer in the gas pipeline measures the gas pressure decay automatically. It has been found that the value of k, the slope of the log of gas pressure versus time response is a good indicator of relative permeability (RP).

  • Availability:
  • Corporate Authors:

    FAVERSHAM HOUSE GROUP LTD

    FAVERSHAM HOUSE, 111 ST JAMES'S ROAD
    CROYDON, SURREY  United Kingdom  CR9 2TH
  • Authors:
    • Lydon, F D
  • Publication Date: 1990-6

Language

  • English

Media Info

Subject/Index Terms

Filing Info

  • Accession Number: 00607002
  • Record Type: Publication
  • Source Agency: Transport and Road Research Laboratory (TRRL)
  • Files: ITRD, TRIS, ATRI
  • Created Date: Mar 31 1991 12:00AM