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Large Hydraulic Four Point Bending Machine


The only machine on the market to accept variable beam lengths

Bending tests are widely used for measuring the stiffness modulus and assessing the fatigue resistance of asphaltic paving materials. Four point bending tests are included in CEN, AASHTO and Chinese test specifications. The specimen is a prismatic beam which is subjected to sinusoidal loading in either the controlled strain or controlled stress modes. This equipment is capable of testing over a wider frequency range (up to 60 Hz) than can be achieved with pneumatic loading systems.

The CRT-LH4PT-BB uses advanced servo-hydraulic technology and a high-speed digital data acquisition and control system together with user-friendly software. During testing both graphical and tabular data are displayed on screen and test data is stored to disc in Microsoft Excel™ compatible format. The test frame is housed in a temperature controlled cabinet with fan-assisted air circulation and a temperature range of -20 to 30°C. The unique constant torque clamping and three-transducer deflection measurement system of the CRT-LH4PT-BB can be configured to accept different beam sizes. This means that the ratio between beam dimensions and maximum aggregate size of test specimens will satisfy the requirements of the relevant European specifications.


  • EN 12697-24 Annex D
  • EN 12697-26 Annex B
  • AASHTO T321-03 (TP8)
  • Chinese Standard

Key Features

  • Frequency range 0.1 to 60Hz
  • High quality servo hydraulic four point bending machine
  • Double acting fatigue rated hydraulic actuator with integral stroke transducer
  • Utilises Star servo valve with ‘Sapphire Technology’
  • Unique three transducer on-specimen deflection measurement system
  • Accepts various beam sizes: 380 to 660mm in length and 50 x 50mm to 100 x 100mm cross-section
  • Temperature controlled cabinet range -20 to 30°C
  • Sinusoidal controlled strain or controlled stress fatigue test modes
  • Constant torque motorized specimen clamping to eliminate errors due to localised beam indentation
  • User friendly software for determination of fatigue resistance and stiffness modulus
  • The possibility to make frequency/temperature sweeps
  • Supplied with certification of a UKAS accredited calibration
  • Covered for noise reduction

Key Uses

  • Mix design
  • End product specification
  • Assessment of new materials


  • Measurement of up to 32 transducers
  • Wave Types:
  • Haversine
  • Pulse
  • Square
  • Triangle
  • Constant
  • Ramped
  • Rest Periods



  • User friendly, intuitive and reliable Windows™ software developed using LabVIEW™
  • Specifically written to meet EN 12697-24 Annex D and EN 12697-26 Annex B
  • The user interface can be translated into the user’s preferred language – please enquire
  • One software package performs both fatigue and complex modulus testing
  • Stored test data can be analysed and compared with other test data utilising a spreadsheet package
  • Utilities are included for curve fitting of acquired data; testing of system’s inputs and outputs; phase correction and a transducer database for storing calibration factors

LH4PT software

*cDAC & Dimension optional. Please enquire for details.


Accessories are not included in the price of main device (unless stated otherwise) and may be purchased separately if required.

CRT-PVC-BEAMLARGE PVC Dummy Specimen 100x100mm
CRT-LH4PT-COMPAIR Integrated Compressed Air Option


Technical specifications are subject to change without notice.

Force Transducer ±10 kN
Specimen Transducer Range mm 3 x ±1
Actuator stroke mm 10
Frequency Hz 0.1 to 30
Temperature (Integral Cabinet) -20 to 30°C
Electrical Supply¹ 3 Phase 415 Volts 50 Hz @ 16A
Compressed Air 7–10 bar @ 100 L/min (optional integral extra)
Dimension mm (W x D x H) 1050 x 1600 x 2100
Working space required mm (WxDxH) 2050 x 2600 x 2300
Weight (approx.) Kg 650
PC Included

¹ others available upon