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CRT-NU14 - UNIVERSAL SERVO PNEUMATIC TESTING SYSTEM

CRT-NU14 - UNIVERSAL SERVO PNEUMATIC TESTING SYSTEM

TEST METHODS

Asphalt
ASTM D4123 - ASTM D3497- BS DD 226
EN 12697 24 - EN 12697 25 - EN 12697 26
AASHTO TP62 -AASHTO TP31- AASHTO TP8

Unbound materials
AASHTO TP46 - AASHTO T307-NCHRP 1-28A

SPT tests
Dynamic modulus for permanent deformation
Dynamic modulus for fatigue cracking

Universal test software
Allows user designed test routines that can include multiple
wave types and methods of data acquisition

The NU14 is a servo-pneumatic machine for testing asphaltic paving materials. Maximum loading capacity is normally up to 14kN with an air supply of 7 bar. The actuators are double acting which means that both compressive and tensile forces can be applied. This gives a high degree of control over the load waveform and enables loads to be cycled between tension and compression at high frequencies for tests such as bending beam fatigue.

This machine is a development of the NAT which was conceived by K E Cooper and Professor S F Brown at the University of Nottingham. The use of a high precision pneumatic servo valve in conjunction with a specially conceived low friction actuator, and sophisticated data acquisition gives performance that is equal to many servo hydraulic systems.

Allied to state of the art Windows software, this system digitally generates the waveforms applied by the actuator so that materials are tested under conditions that are simulative of those applied by static or moving vehicles. The actuator is double acting which means that both compressive and tensile forces can be applied. This gives a very high degree of control over the load waveform and enables loads to be cycled between tension and compression at high frequencies. Most international test standards are available in software, and, if necessary, users can use the LabView software platform to develop their own test routines.

FEATURES

•Digitally controlled servo-pneumatic system
•Cycling at frequencies up to 70Hz
•14kN static at 7bar (19kN static at 10bar), 9kN at 2.5Hz for modulus tests (This is sufficient for most high modulus materials)
•Built in displacement transducer for precise position control
•Control & Data Acquisition system with precision 16 bit digital servo-control
•Load and force transducers calibrated to United Kingdom Accredited Standards
•Transducers available for modulus, permanent deformation and triaxial tests
•A wide range of test fixtures is available for asphalt and unbound tests
• Triaxial cells for 100mm and 150mm diameter specimens for the testing of unbound materials
• Normally supplied with temperature controlled cabinet (-10ºC to +60ºC, ±0.2ºC)
• Software to perform American, Chinese and European standard tests
• Universal test software routine


CRT-SH SERVO-PNEUMATIC UNIVERSAL TESTING SYSTEM ASPHALT PHYSICAL TESTING

The CRT-NU14 can be used for:
• Mix design
• End product specification
• The assessment of new materials
• Failure investigation
•Pavement assessment

SYSTEM ELEMENTS

CRT-SH SERVO-PNEUMATIC UNIVERSAL TESTING SYSTEM ASPHALT PHYSICAL TESTING

CRT-NU14. Universal servo-pneumatic asphalt testing system comprising:
Rigid stainless steel test frame with adjustable height cross-head
Pneumatic actuator with low friction seal and pneumatic servo-valve and integral displacement transducer (14kN maximum static load at 7bar - up to 19kN at10bar)
Load transducer (±20kN capacity)

Acquisition and control system comprising:
• Signal conditioning for load transducer, 2 thermocouples and 2 displacement transducers (optional additional displacement transducer channels)
•Servo-amplifier for PID control of servo-valve
•Power supplies
• Multifunction high speed, 16bit analogue to digital, 16bit digital to analogue and digital input-output card for closed loop computer control of system (National Instruments)
• Pneumatic fittings including filter, regulator and tubing
• All signal and power cables
• Thermocouples
• Basic operational and diagnostic software
• Instruction manual

TECHNICAL SPECIFICATIONS




See also:
NAT Asphalt Testing System
Universal Servo-Hydraulic Test System
Four point beam fatigue test
The Wheel tracker
Hamburg Wheel tracker
Wheel tracker EN12697-22 Large device CRT-WTENLD
Roller Compactor
Large device EN roller compactor