Compression Testing Machines

Compression Testing Machines

IS 516, IS 14858

It is important to test the quality of cement concrete work. Testing of raw material fresh concrete and hardened concrete is an inseparable part of any quality control program for concrete which helps to achieve higher efficiency of the material used and greater assurance of the performance of the concrete in regard to both strength and durability. Heico compression machine have been designed to accurately measure the compressive, flexure, strength of concrete. Following pages describe various models of HEICO CTM, selection can be made from these models to suit the requirement.

Portable Compression Testing Machines (Hand Operated)

For carrying out Compressive Strength Test on mortar and concrete cubes.

The frame is a totally welded type or pillartype to give structural stability. Even withsome eccentric loading, the frame’s stability is not affected at all. The lower plate of the frame has integral jack/bolted jack and the upper plate carries the spherical seating. A special type of pump with concentric plunger is attached to the loading unit. Pressure can be created to themaximum with minimum possible effort. The outer plunger is for filling the gapwithout taking load and gets automatically disconnected on closing of the gap.

Pressure gauge is fixed at an angle for the ease of readings and is calibrated against standard dynamometer calibrated by either NPL or NCCBM.

Accuracy of the machine is maintained within ±2% as per IS 516, BS 1610 grade Ior on special request can be calibrated asper BS 1881, DIN 51220.

Motorised Compression Testing Machines

Electrical version of Compression Testing Machines capacity ranges from 100 kN to 5000 kN.

These machines are suitable for testing cubicalspecimen of 10 cm, 15 cm or cylinder of 15 cm dia x 30 cm height. Smaller specimens can be tested with fixtures/spacers. Any machine with the higher capacity is a special model that can be manufactured as per the customer requirement. These machines are stable with a high degree of accuracy and stability conforming to IS 516/IS 14858. On special request the machine can be made to meet the essential requirements of BS 1881 or DIN 51220, 51223.

Basic machines have the following components:- Load Frame

Load frame is a steel welded structure. It is designed to withstand a few million times of full cycles of loading without any sign of distortion or fatigue. These frames are light in weight. The base carries a fine finished hydraulic ram and the lower platen. The top plate has the spherical seating to take care of any irregularity of the specimen surface or slight misplacement of the specimen from the central position. As a safety precaution front cover is provided, as a protection to the operator while at the same time giving an unobstructive view of the speci men under test.

Pumping Unit

Pumping unit is attached on the right hand side of the loading unit. It is a multi plunger pump with booster arrangement .This facility is for fast raising of ram without load. Pump is submerged in the tank and is powered by 1.5 kW electric motor. Operating on 220 volts 50Hz AC supply. (other voltages optional). Power pack gives non-pulsating flow to the hydraulic ram.

This ensures smooth loading of the specimen which can be seen by the movement of the load gauge/digital display. The flow of the oil can be precisely controlled by the strain control knob located at a convenient height. With the proper check on the oil, the life of the pumping unit and the hydraulic ram is almost as long as, life of machine. Keeping in view the operators safety regulations, safety features like expanded sheet metal door, overload relief valve is provided as standard in the hydraulic circuit.

Compression Testing Machines with Single Gauge

This particular series of models have loading unit, pumping unit and load gauge with safety valve.

Compression Testing Machines with Three Gauge

These machines are similar to the earlier series except that these systems have three gauges instead of a single gauge. Other essential elements
like power pack and loading unit remains the same as described earlier.

Compression Testing Machines with Digital Readout Unit

HLM 592

This series of machines have loading unit and pumping unit as described earlier. Indication of load is on digital display system, which is directly indicated, in respective engineering unit. The electronic display unit is totally microprocessor based with a built in RS232 serial port. It has indication for load, peak load, and pace rate indicator.

Pace rate is achieved manually by controlling the flow control knob and the system is released manually after
the peak load is achieved.

Readings can be transferred through the serial port to the computer at an interval of 1 sec till specimen failure

Compression Testing Machines with Digital Readout Unit with Storage Facility

HLM 592S SERIES

This Model is similar to Model- HLM592 except that it has Microprocessor based digital display system with storage facility of test results in place of simple display unit.

Other essential parts like Hydraulic Pumping system and loading unit remains the same as described earlier in Model-HLM592.

Microprocessor based Digital Display System with Storage facility

Indication of load is on digital display system, which is directly indicated in respective engineering unit. The electronic display unit is totally microprocessor based with a built in USB/ Ethernet. It has indication for load, peak load, pacing rate and pace rate indicator. Load is indicated in terms of kN. System has facility to store results of more than 5000 tests in the memory, which can be off loaded on a Computer.

Pace rate is achieved manually by controlling the flow control knob and the adjustment can be made by observing the error on the display and the system is released manually after the peak load is achieved.

SALIENT FEATURES OF SYSTEM

  • Menu driven interface
  • Facility to perform various operations such as TARE, PROGRAMMING, START, STOP etc. at front panel display
  • Programmable Rate of loading (Load rate) and sample parameters (Shape, Dimension, weight etc.) through Panel
  • Pace Rate indicator and can be controlled manually through fine control knob
  • On-line display of Load and Peak Load with recording of Peak load
  • Automatic data logging on stop button
  • Real time clock check to keep automatic track of the date, time and runs
  • Transmission of Data to computer through Ethernet/USB/RS232 port
  • Test results can be stored in the electronic unit and can be retrieved HLA592 SERIES

Automatic Compression Testing Machine (Load/ Stress Control)

HLA 592 SERIES

HEICO Automatic Compression Testing Machine is capable of conducting compression tests on concrete specimens and allied products. It is a state of the art machine in which loading is controlled automatically through a combination of advance electronic and hydraulic system. The complete system consists of Load frame, Hydraulic pumping unit & Microprocessor based digital Indicator.

This Model is similar to Model- HLM592 except that it has Microprocessor based digital display system with storage facility of test results automatic controlling of programmed pace rate up to failure in place of simple display unit.

Other essential parts like Hydraulic Pumping system and loading unit remains the same as described earlier in Model-HLM592.

The pace rate is programmable and controlled automatically.

The equipment has an arrangement for automatic pacing system, which is achieved by the combination of advance hydraulic and electronic system. Control signal from the electronic system is passed on to the drive of the motor through the P.I.D. Controller which in turns control the flow to the hydraulic ram thereby keeping the pace rate within +/- 2% of the pre programmed value. After failure load, the machine has to be released through operation of ball valve. All controlling is through the membrane key board.

MICROPROCESSOR BASED TOUCH PANEL DISPLAY & CONTROL SYSTEM

Control system provides the digital servo control, Ramp generation for the machine, data acquisition, etc. for the continuous operation of the system.

SALIENT FEATURES OF SYSTEM

  • Menu driven interface
  • Facility to perform various operations such as TARE, PROGRAMMING, START, STOP etc. at front panel display
  • Programmable Rate of loading (Load rate) and sample parameters (Shape, Dimension, weight etc.) through Panel
  • Standalone system to operate the machine (Start, Stop and reset) without computer
  • Automatic Pace Rate control
  • On-line display of Load and Peak Load with recording of Peak load
  • Automatic data logging on stop button
  • Real time clock check to keep automatic track of the date, time and runs
  • Transmission of Data to computer through Ethernet/USB/RS232 port
  • Test results can be stored in the electronic unit and can be retrieved

Software – The system is supplied with necessary software for data acquisition, analysis and graph plotting.

DIGITAL COMPRESSION TESTING MACHINE

• Lower and Higher capacity models on request

NOTE- THE DETAILS AND DIMENSIONS GIVEN HERE ARE OF STANDARD MODELS. HOWEVER, THE SPECIFICATIONS CAN BE MODIFIED TO SUIT CUST OMER REQUIREMENT.

Computer Controlled Servo Hydraulic Compression Testing Machine (Both Load & Displacement Controlled)

HCA592 SERIES

The detailed Specification of the system is given below:

HEICO Automatic Servo controlled Compression Testing Machine is capable of conducting compression tests on concrete specimens and allied products. These compression testing machines are state of the art machines based on the principal of CLOSE LOOP. The system can be loaded in load, displacement or strain control basis. The system accuracy is better than ± 1%. A special type of 4 piece oil filled spherical seating is provided conforming to IS 14858-2000.

The system has an arrangement for automatic pacing system, which is achieved by the combination of advance hydraulic and electronic system. Control signal from the electronic system is passed on to the servo valve through P.I.D. Controller which in turns control the flow to the hydraulic ram thereby keeping the pace rate within permissible limit of the pre programmed value.
NOTE: The machine is supplied with windows based user friendly for Data acquisition and analysis. It has the features for on line graphical presentation in addition to the numerical test results.

Salient Features:

  • Conforming to Testing Procedures laid down in various national and international standards for building material/ concrete specimen
  • Suitable for static and low frequency dynamic tests on rock, concrete and other building materials.
  • Based on SERVO HYDRAULIC CLOSED LOOP FEEDBACK control mechanism
  • Capable to control multiple frames (up to 4 from same hydraulic power pack)
  • Fully Computer Controlled operation with User friendly Software
  • Controlling on Load or Displacement or user supplied strain gage (quarter Bridge) or External displacement sensors as mounted on specimen
  • High stiffness compression loading frame
  • High speed Data Acquisition card with 100 kHz sampling rate
  • Programmable Rate of Loading (Pace Rate) in all control modes, including user input file for loading/hold/ unloading applications
  • Facility to change the parameter like rate of load or rate of displacement without stopping and restarting during testing
  • Facility for setup and execution of monotonic, cyclic and user defined test procedures
  • 8 Additional input channels for external transducers such as load cell, pressure transducer, LVDT etc. and the same can be used for controlling also
  • Windows based user friendly Application Software for controlling and data acquisition
  • Start, Stop, Hold operation through computer
  • Inching/Release operation to set Sample
  • Auto release facility after specimen failure
  • Facility in the software to study Post failure behaviors of specimens
  • Online Plotting of Graphs (Load v/s Displacement,Load v/s Time, Displacement v/s Time) with display of data
  • Advance Statistical Analysis
  • Safety Limits for Over Load, over travel etc.

The system has following main components-

  • Loading Frame
  • Hydraulic Power Pack
  • PC Based Control System and Application Software
  • Additional Accessories

Loading Frame

Load frame is steel welded structure with high stiffness where top and bottom plates are tied with side place.

It is designed to withstand a few million times of full cycles of loading without any sign of distortion or fatigue. These frames are light in weight.

The top plate has the upper spherical seated platen with oil filled ball seat assembly as per IS : 14858-2000 to take care of any irregularity of the specimen surface or slight misplacement of the specimen from the central position. The upper and Lower loading platens are hardened and has hardness of 55HRC. The flatness tolerance is 0.03 mm and the roughness value (Ra) in the range of 0.4ìm.

The base carries a fine finished servo controlled hydraulic cylinder with hardened and finest abraded piston.The bearing surface of the Lower Loading platen has marking inscribed to facilitate proper centering of cubical and cylindrical specimen of different sizes.

The frame is provided with safety guard doors and transparent fragment guards (both front and rear) as a protection to the operator while at the same time giving an unobstructive view of the specimen under test. Proximity switch/ Limit switch is provided as a safe guard against over travel.

A load cell or pressure transducer is fitted in the frame with testing range from 1% to 100% capacity of machine with an accuracy of ± 0.5% of indicated load. A displacement transducer is fitted with the ram to measure the deformation of the specimen.

B) HYDRAULIC POWER PACK

Hydraulic power supplies are compact in design and are suitable for the supply of required flow and pressure for the movement of the actuator. It has an oil tank of adequate capacity, vane type pump powered by a three phase motor. All the electrical controls including the temperature controller are fixed on one side of the tank. It includes all the accessories like pressure line filter, return line filter, oil level, relief valve, pressure gauge, digital temperature indicator and air cooled heat exchanger. Anti vibration mountings are provided as standard along with the HPS.

Technical specifications:

Flow of the pump : 2 & 4 LPM
Motor capacity : 3 H.P.
Capacity of the tank : 40 Litres
Max. Operating pressure : 210 – 600 Bars
System will be supplied with necessary cable and fittings
for the operation of the machine. Total machine operates on 440VAC 3 phase supply.

Note: Hydraulic Power pack can be supplied with manifold block with solenoid valves to operate multiple loading frames (Max. up to four can be operated through same hydraulic power pack

C) PC BASED CONTROL SYSTEM AND CONTROL SOFTWARE

Control system provides the digital servo control, Ramp generation & low frequency wave generation for the machine actuator, data acquisition, etc. for the continuous operation of the system.

(a) Signal Conditioning & Controlling Unit

HEICO Servo controller basically consists of signal conditioning unit and controlling unit. Signal conditioning unit receives the output signal from the various transducers (Load cell/Pressure Transducers, LVDT, Strain gauge etc.) and amplifies and process that signal as per the requirement and transfer it to computer through connecting cables where it is accepted by the data acquisition system. The output from the signal conditioning unit for each transducers ranges from 0-5V.

Control is on Load/ Stress or Displacement or Strain basis. It consists of dedicated servo-controller card that gives the desired processed signal through the P.I.D controller to the servo valve to operate in selected control mode. It also sends the signal to computer and accepts the command from the software to operate in desired manner. The parameters like rate of loading, safety limits for load can initially be programmed through the software. The facility is given to program the rate of loading from 0.1kN/sec-50kN/sec in Load control and 0.01mm/sec-1mm/sec in displacement control.

Specifications of Controller

  • Auto PID operation with Closed loop update rate of 10 kHz to control Pace rate automatically as programmed in the software
  • No. of control channels: 4 (Load/Displacement/ Strain/ External LVDT Control)
  • Selection and controlling of multiple frames (Up to 4)
  • Type of Loading: Static and low frequency cyclic
  • High speed Data Acquisition card with 100 kHz sampling rate
  • Computerised control operation to Start, Stop & Hold the test system
  • Resolution: Load : 0.1kN up to 1000kN & 1kN above 1000kN
  • System accuracy

Load accuracy : < ± 0.5% of indicated value |

  • Displacement accuracy: <± 0.5% of indicated value
  • Displacement Measurement: Through LVDT
  • Displacement Range: 50mm
  • Displacement Resolution: 0.001mm
  • Rate of Loading:

Load control: 0.1kN/sec. to 50 kN/Sec

Displacement control: 0.01mm/ sec to 1mm/sec

Rate of increase of net deflection: 0.00016mm/sec – 0.001mm/sec.

  • 8 Additional input channels for external transducers such as load cell, pressure transducer, LVDT etc.
  • Supply Input- 220-240 VAC, 50 Hz
  •  

(b) Computer for Controlling and Data acquisition

System is provided with dedicated computer of following or better configuration at the time of supply with built in data acquisition card.

Computer

Intel i5 processor, 320 GB HDD, 4GB RAM, DVD R/W drive, Key Board, Optical Mouse, 6USB Ports, 19” LCD Monitor, Deskjet Colored Printer, UPS

Application Software

Application software is the integral part of the system for precise operation, Data Acquisition, storage, processing, analysis and reporting. The software package includes test routines for Compression and Flexure tests on concrete according to relevant standards such as IS, EN, ASTM etc.

Test Software- Salient Features

  • Windows based user friendly software with easy graphical user interface
  • Programmable rate of loading/displacement in load and displacement control i.e. kN/sec. or N/mm2/sec or mm/sec or micro strain/sec. and sample parameters (Shape, Dimension, weight etc.)
  • Facility to set up and execution of monotonic, cyclic and user defined test procedures
  • Facility to create Test Profiles for different samples
  • Provides block programming with sine, square, triangle, ramp, hold, processes, and ability to play digitized profiles
  • Facility to change the rate of loading or rate of displacement during the test
  • Auto Fast lift operation to adjust the gap
  • Autozeroing/ Independent Taring of each channel
  • Auto release of machine after sample failure
  • To see the post failure behavior of the specimen
  •  Computer/Software programmable Safety Limits for Load and Displacement
  • Facility to hold load at desired point and restart the loading during the test.
  • Online display of numerical values of Load, Stress and Displacement simultaneously with peak hold facility
  • Online plotting of data of Load v/s Time, Displacement v/s time, Load v/s Displacement, Stress v/s Strain graphs
  • Real time clock for tracking date, time and runs
  • Facility to save test data along with order information about the specimen such as age, specimen no., size, dimensions etc. in user defined file/directory
  •  Facility to avoid unauthorized use by creating users password

Analysis Software

  • Plotting of following graphs-

a) Load v/s Time
b) Displacement v/s Time
c) Load v/s Displacement
d) Stress v/s Strain
e) Stress v/s Time

  • Calculation of various results (Young’s modulus, Maximum strain, Compressive Strength, Flexural Strength, Flexural toughness etc.)
  • Facility to plot the data for a selected run
  • Comparative analysis using multi graphs
  • Statistical analysis of the test results
  • Batch Summary Report Generation
  • Detailed Summary Report Generation
  • Facility to print Test Reports
  • Facility to Export Data to MS Excel

SAFETY FEATURES

The following safety features are incorporated in the system-
1. Over Load protection
2. Over Travel protection
3. Front door for operator safety
4. Low oil level Indicator
5. Protection against contamination of oil