mastrad  logohome








NAT NOTTINGHAM ASPHALT TESTING SYSTEM - ASPHALT PHYSICAL TESTING

the Nottingham Asphalt Tester (NAT)

See also Universal Servo-Hydraulic Test System-SH 10kN



NATs are used by national and regional laboratories, universities, oil companies, contractors and consulting engineers worldwide. Trials have demonstrated that NAT tests give excellent correlation with other test methods such as bending beam and wheel tracking.

NAT NOTTINGHAM ASPHALT TESTING SYSTEM - ASPHALT PHYSICAL TESTING
The NAT provides the most inexpensive and user friendly means of measuring and assessing the mechanical properties of asphaltic paving materials on a routine basis. It is designed to derive the maximum information about a material using either cores cut from the highway or laboratory moulded specimens.

NAT NOTTINGHAM ASPHALT TESTING SYSTEM - ASPHALT PHYSICAL TESTING


APPLICATIONS

The NAT can be used for:-

  • Mix design
  • Quality control
  • End product specification
  • The assessment of raw materials
  • Failure investigation
  • Pavement assessment


  • SOFTWARE

    The NAT can be used to carry out the following range of tests:
  • Indirect tensile stiffness modulus
  • Static creep
  • Dynamic creep
  • Indirect tensile fatigue
  • Vacuum triaxial
  • Indentation
  • Test method numbers:

    CEN PrEN 13108/12697-26
    CEN PrEN 13108/12697-25
    CEN PrEN 13108/12697-24


    FEATURES

  • Easy to maintain pneumatic loading system
  • Easy to set up
  • User friendly windows software
  • Rapid test throughput
  • Tests 100mm and 150mm dia. road cores or moulded test specimens
  • Calibrations traceable to National Standards
  • User support by telephone, fax or Email
  • NAT NOTTINGHAM ASPHALT TESTING SYSTEM - ASPHALT PHYSICAL TESTING
    The NAT can measure the mechanical properties of gyratory compactor specimens

    NATs are used by national laboratories, universities, oil companies, contractors and consulting engineers, worldwide. Trials have demonstrated that NAT test results give excellent correlation with other test methods such as bending beam and wheel tracking.

    The NAT provides the most inexpensive and user friendly means of measuring and assessing the mechanical properties of asphaltic paving materials on a routine basis. It is used to derive the maximum information about a material using either cores cut from the highway or laboratory moulded specimens.



    NAT NOTTINGHAM ASPHALT TESTING SYSTEM - ASPHALT PHYSICAL TESTING

    SPECIFICATION FOR AN ASPHALT TESTING MACHINE

    The apparatus shall consist of the following:


    A load frame fitted with a pneumatic actuator and load transducer and capable of applying vertical loads in the range 0 to 4.3kN.

    An indirect tensile subframe, alignment jig, LVDT yokes, LVDT deformation transducers and software necessary to carry out Indirect Tensile Stiffness Modulus (ITSM) tests on both 10Omm and 150mm diameter cores or moulded cylindrical specimens.


    A 150mm or 10Omm diameter (customer to specify) PVC specimen for routine checking of (ITSM) transducer accuracy.


    Hardened, ground and polished platens, LVDT deformation transducers, LVDT mounts and software necessary to carry out both Static Creep and Repeated Load Axial tests on both 100mm and 150mm diameter specimens.


    A unit for the conditioning and regulation of the pressurized air supply.

    An electronic interface unit, high resolution, high speed 16 bit multifunction card and parallel link through which all data acquisition and control tasks are carried out by the host computer. The interface unit shall contain all necessary power supplies and signal conditioning for a load transducer, two thermocouples and two deformation transducers with the capability of expansion for up to three additional transducers (ie. up to eight transducers). The data acquisition and control system shall be capable of direct memory access (DMA) for rapid data transfer during tests where timing is critical.

  • All pneumatic and electrical connections.
  • Transducer calibration and diagnostic software.

  • A detailed instruction manual


  • The software shall run under Windows 3.1195 to provide a "user friendly" means of carrying out testing using menus, graphical displays and help screens to provide a step by step method of enabling the operator to obtain repeatable and reproducible results. The host computer shall automatically carry out the test and calculate the results. The operator shall have the option of storing the test data on disk and for printing it out when the test is completed. The stored data shall

    be in a format which can be readily imported into all popular spreadsheets (eg. LOTUS 123 or EXCEL etc.) for subsequent analysis and comparison.

    A temperature controlled cabinet shall be provided which is capable of controlling temperature in the range -10 to +60 C with temperature fluctuation of 0.2C and temperature variation of 0.5C.

    The apparatus shall be capable of carrying out the following tests:
  • Indirect tensile stiffness modulus to DD 213:1993/1.
  • Resilient modulus to ASTM 04.03 D4123/2. (Poisson's ratio assumed)
  • Indirect tensile fatigue test (DD in preparation).
  • Uniaxial creep to DD 185:1993/3 .
  • Repeated load axial test to DD 185:1993 .


  • The apparatus shall be equipped with a minimum of a 386SX IBM (or compatible) PC with 3.5inches-xl.44 MB floppy, 1 OOMB hard drive, 1 MB RAM (at least 4 MB RAM for Windows software) and SVGA graphics. An inkjet printer is suitable for routine printouts.

    The apparatus shall be supplied with pressurized air at 7bar and better than 6cfm.

    References:

      1. DD213:1993. Method for determination of the indirect stiffness modulus of bituminous mixtures", British Standards Institution.
      2. D4123-82. Standard test method for indirect tension test for resilient modulus of bituminous mixtures, Annual Book of ASTM Standards, Vol 04.03.
      3. DD185:1993. Methods for assessment of resistance to permanent deformation of bitumen aggregate mixtures subject to unconfined uniaxial loading, British Standards Institution.