AC-250 Series Fully Automatic Concrete Compression Machines perform complete strength tests for concrete cylinders, beams, cubes, cores, and other sample types, with minimal operator input. An automated test cycle is initiated with a single button on the touchscreen controller. The machine controls specimen contact, pre-loading, rate of load, break detection, data collection, and return of the piston to the home position following specified requirements for the selected test method. Variations in load rates and test procedures are eliminated, ensuring accurate, repeatable, and documented results, strictly conforming to ASTM, AASHTO, and other testing specifications.
Selection of the test method, sample type, specimen data, and test parameters are made on the touchscreen of the controller. Force, stress, and rate of load are displayed simultaneously during a test, with an option to show real-time load vs time or stress vs strain graphs. Load rate and applied force are precisely regulated by feedback during sample loading. USB and LAN ports, along with Wi-Fi capability, allow immediate printing of tests, or easy data collection and transfer to the user’s PC for reporting of results using a USB flash drive.
A menu button prints each test or transfers test data in summary form. Testing laboratory, sample ID, and client information are stored for error-free reporting and distribution. The diagnostics feature instantly displays the status of the emergency-stop button, drive system, data communication, pressure transducer, and over-travel limit switch. An indication of a fault condition in any of the systems must be resolved before testing can proceed.
The energy-efficient integrated electric motor and hydraulic pump operate at variable speeds to achieve and maintain required pressures based on loading program demands. This state-of-the-art drive system is dramatically quieter, eliminates pressure variations from over-heated oil, and extends the service life of the hydraulic components.
The rugged, welded steel frame exceeds ACI 363 requirements for system rigidity and has a total capacity of 250,000lbf (1,112kN). Excessive long-term wear to the hydraulic loading system is prevented by mounting the piston on the top of the frame, where it is unaffected by accumulated test debris. An emergency-stop button, hydraulic safety relief valve, piston over-travel limit switch, and fragment guard door ensure safety for the operator while running tests.
The Automatic Compression Machine units are supplied ready for compression strength testing of 6x12in (152x305mm) concrete cylinders up to 7,000psi (48.3mPa) with user-supplied unbonded neoprene capping pads and steel retainers.
AC-250 models, the standard load frame can test compression and flexural strength. These models may be outfitted with accessories to accommodate additional testing.
AC-250M and AC-250MR models are special factory-modified models. They are outfitted with a different manifold, an optional proportional valve for controlled piston retraction, and either one or two LVDT inputs required to determine ASTM C469 modulus of elasticity (MOE), or MOE and Poisson’s ratio on 4 or 6in (101 or 152mm) cylinders. These modified models are also capable of determining compressive, flexural, and splitting tensile strength tests by using the same component sets (based on test type and frame capacity) as the standard forms. Compressometer and Compressometer/Extensometer testing fixtures for MOE and Poisson’s ratio testing must be purchased separately.
- Windows-based controller regulates testing parameters based on ASTM/AASHTO specifications
- Touchscreen controller is menu-driven for easy test setup
- Minimal operator input is required, increasing productivity with fewer errors
- USB and LAN ports and Wi-Fi capability for trouble-free data management
- Next-generation drive system runs cooler, quieter, and more consistently
- Frame exceeds ACI 363 requirements for system rigidity
- Safety features include an E-stop button, see-through fragment guard doors, a hydraulic safety relief valve, and a piston over-travel limit switch
- 250,000lbf Automatic Concrete Compression Machine (110V, 60Hz or 230V, 50Hz)
- 6x12in Cylinder Test Set for use with Unbonded Caps
- Mounting stand
- Cylinder Test Sets are available for 2x4in, 3x6in, 4x8in, or 6x12in concrete cylinder specimens for compression testing, select from a test set for use with unbonded caps or bonded caps.
- ACA-200 Flexural Test Set allows loading of 6x6in flexural beams
- Cube Test Set for compression testing of 2x2x2in or 6x6x6in cube specimens
- Tensile Cylinder Splitting Set allows testing of 4x8in or 6x12in concrete test cylinders
- Compressometers measure the deformation and strain of test cylinders to determine the static modulus of elasticity (MOE).
- Compressometer/Extensometers are used to measure deformation and strain for MOE and Poisson's ratio determinations, available for 4x8in or 6x12in cylinders.
- Grout Prism Test Set can adapt compression machine for testing 3x3x6in grout prisms.
- Proppant Crush Testing Set can be installed for use in hydraulic fracturing for the oil and gas recovery industry.
- Perpendicularity Verification Devices (PVDs) are used to verify the proper perpendicular alignment of concrete cylinders during compressive strength testing.