STANDARDS: EN 12390-3, 12390-4; BS 1881, ASTM C39
Automatic range of 2000 kN, 3000 kN and 4000 kN, 5000 kN capacity four column compression testing machines have been designed for reliable and consistent testing of a wide range of specimens. Machines conﬁrms all EN, ASTM and BS standards written above. These also meet the requirements of CE norms for the safety and health of the operator.
Testing machines are supplied with EN compression platens as standard. Machines also comply with the ASTM C39 standard when used together with suitable platens.
Tests can be performed by either Digital Readout Unit or on a computer with using free Software.
The Automatic Compression Testing Machines allow inexperienced operators to perform the tests. Once the machine has been switched on and the specimen is positioned and centered by the help of centering apparatus. The only required operations are;
• Setting test parameters, including pace rate (only required when the specimen type is changed).
• Pressing the START button on the control unit
• The machine automatically starts the rapid approach, when the specimen touches the upper platen the rapid approach is ended and starts loading at the pace rate that selected by user and stops once the specimen fails.
Four Column Automatic Concrete Compression Testing Machines consist of;
• Heavy duty Four Column Load Frame,
• Automatic Hydraulic Power Pack,
• Digital data acquisition & control system,
• Distance Pieces, Ø 200x30 mm, Ø 200x50 mm and Ø 200x80 mm,
• Upper Platen (with ball seating assembly) Ø300 mm,
• Lower Platen Ø300 mm,
• Loading Cylinder Assembly & Limit Switch for safety,
• Front and Rear Protective Doors for safety.
Concrete Compression Load Frame
Capacities of 2000 kN, 3000 kN, 4000 kN and 5000 kN Four Column Load Frames are available models for column type frames.
The Four Column load frame provides the stability needed for accurate and repeatable test results over the years of operation.
Upper Platens / Lower Platens
Upper Platen (with ball seating assembly) Ø 300 mm, Lower Platen Ø 300 mm. The platens enable the testing of a wide variety of cylinder, cube blocks or similar samples.
• Manufactured from high quality steel, which is then hardened, smoothed and ﬁnished.
• The roughness value for the surface texture of the auxiliary platens is ≤ 3.2 µm.
• Ø 300 mm Upper Platen (with ball seating assembly) and Lower Platen have centering rings on the lower platens for proper centering of samples
Distance pieces are used to reduce the amount of vertical clearance between the upper platen and the lower platen. Supplied with Ø200 mm distance pieces.
Loading Cylinder Assembly & Limit Switch
All frames have a single acting up stroking ram. The diameter of piston changes with regard to the capacity.
The maximum ram stroke is 50 mm, a limit switch is ﬁtted to prevent over travel of the ram which cuts the power to the pump for safety.
At the end of the test process to start a new test the piston returns to default position. The pressure transducer is used for load measurements.
There is a low friction coaxial PTFE seal between the cylinder and the piston ﬁtted to the cylinder.
HYDRAULIC POWER PACK AND DIGITAL DATA ACQUISITION & CONTROL SYSTEM
Hydraulic Power Pack
Automatic Hydraulic Power Pack, dual stage, controlled by digital readout unit is designed to supply the required oil to the load frames for loading.
Controller unit has a simple and compact conﬁguration. The Hydraulic Power Pack is equipped with 4 wheels for easy carriage and ﬂexible installation.
Very silent power pack can load the specimen between 1 kN/sec. to 20 kN/sec, with an accuracy of ±5%. A Rapid approach pump is supplied as standard. Safety valve (maximum pressure valve) is used to avoid machine overloading.
Maximum working pressure of the system is 400 bar.
Dual Stage Pump
The dual stage pump is formed by two groups;
1. Low pressure gear pump
2. High pressure radial piston pump
On the dual stage pump, a high delivery, low pressure gear pump is used for rapid approach, while a low delivery, high pressure radial piston pump is used for test execution. The rapid approach facility shortens the time interval from piston start until the upper platen touches to the specimen. This excellent feature helps to save a lot of time when a large number of specimens are going to be tested.
The motor which drives the dual pumps in an AC motor and it is controlled by motor inverter. The variation in the oil ﬂow is executed with the variation of the rotation speed of the motor.
A distribution block is used to control the oil ﬂow direction supplied by the dual stage pump, the following parts are ﬁtted to the distribution block; Solenoid valve, Safety valve (max. pressure valve), Transducer, Low pressure gear pump and High pressure radial piston pump.
High Precision Pressure Transducer
All models are supplied in Class 1 starting from 50 kN as standard EN 12390-3, 12390-4, BS 1881 and ASTM C39. The Natek range of Automatic Machines can be upgraded with option High Precision Pressure Transducer special calibration Class 1 starting from 1% of the full range.
This unique performance enables the machines to be used for a considerable number of applications including:
• Early age (2 or 3 days) compression strength tests
• Flexural and splitting tests by using proper accessories
• Mortar (Cement) compression tests by using proper accessories
The tank includes enough oil to ﬁll the mechanism which pushes the ram during the test.
The level and oil temperature can be seen on the indicator ﬁtted to the tank. It has 25 L capacity. Hydraulic motor oil, number 46, must be used.
Digital Data Acquisition & Control System
The unit is designed to control the machine and processing of data from load-cells and pressure transducers which are ﬁtted to the machine.
All the operations of the unit is controlled from the front panel consisting of a LCD display and function keys.
The unit has easy to use menu options.
Digital graphic display unit loading rate of the time of Testing and load values can be monitored.
Digital graphic display is able to draw real-time “Load vs. Time”.
Sample, company, laboratory and test values can be entered in the programme.
Load-time graphic, test reports and sample reports can be taken.
Software provides test data, results, and the load-time graphs can be seen at LCD screen.
The Automatic Compression machine can be controlled (Start, Stop commands) by a computer with the software free of charge. This software provides data acquisition and management for compression, tensile and splitting tensile test throughout the test
execution. The advanced functions for data base management provide an easy navigation of all saved data. The test results certiﬁcate includes all descriptive information. Therefore, test parameters can be set and details about the test carried out such as client details, test type, specimen type, user info and other information required can be entered and printed out as well as test report and graph.
Software can be performed in Turkish and English.
Test results, graphics and properties of 24 diﬀerent specimens can be saved in one folder. Old test folders can be reviewed.
User can highlight all 12 diﬀerent specimen curves in diﬀerent colors on the graphics.
Frequently used information like name and location of the laboratory, type and dimensions of mostly used specimens are held in memory and can be written automatically by right clicking on information boxes and selecting frequently used text in menu.
User can access any data of previously completed tests and use in his/ her new report since most of the tests have same structure and properties.
• Pace rate control from 1 kN/sec to 20 kN/sec depending on piston size.
• Can control 2 frames (optional)
• Can make test with load control.
• Real time display of test graph.
• Analog channels for diﬀerent frame load cells
• RS-232 serial port connecting for computer interface
• LCD display
• 2 diﬀerent unit system selection; kN and kgf
• Multi-language support (English and Turkish)
• 2 diﬀerent unit system selection; SI and Metric
• Real-time clock and date
• Free of charge PC software for the test control and printout the test report.
• Maximum pressure valves to avoid machine overloading
• Piston travel limit switch
• Emergency stop button
• Software controlled maximum load value
• Front and rear transparent durable Plexiglas guards