A material testing machine applies a controlled, measured force to a specimen until it deforms or breaks, and records the load (and often the displacement) so you can calculate properties such as compressive strength, tensile strength, yield strength and flexural strength. The two main types are compression testing machines, used mainly for concrete cubes and cylinders, and universal testing machines, which can also pull specimens apart in tension and perform bend and shear tests.

A compression testing machine only pushes: it squeezes a specimen between two platens, which is what concrete cube, cylinder, brick and paver tests need. A universal testing machine has grips as well as platens, so it can pull (tension), push (compression), bend and shear. Use a compression machine for concrete quality control and a universal testing machine for reinforcing steel, metals, wire, chain and mixed testing work.

Multiply the expected strength by the loaded area. A 150 mm cube has an area of 22 500 square millimetres, so a 40 MPa cube fails at about 900 kN, a 60 MPa cube at about 1350 kN and an 80 MPa cube at about 1800 kN. A 2000 kN machine covers normal structural concrete in 150 mm cubes. For high-strength concrete above about 85 MPa in 150 mm cubes, choose 3000 kN.

Cement strength tests use 40 × 40 × 160 mm prisms that fail at loads of only a few kilonewtons in bending and up to about 100 kN in compression, so a 2000 kN concrete press is too coarse at the bottom of its range. A dedicated cement flexural and compression machine such as the HYE-300B, with separate 300 kN and 10 kN load frames, gives better resolution for cement and mortar work.

On a manually loaded machine (CTM-A, SYE-B, OBRK-2000) the operator controls the loading rate with a valve while watching the displayed rate. A fully automatic machine (CTM-E, CTM-F, HYE-B) uses electro-hydraulic servo control to hold the loading rate set for the test standard, then holds or releases the load and calculates and prints the result. Automatic machines give more repeatable results between operators and suit busy commercial and accredited laboratories.

Use the bar's cross-sectional area times its ultimate tensile strength. Taking about 600 MPa as a working ultimate strength for 450 MPa grade bar: a 16 mm bar breaks at about 120 kN, a 25 mm bar at about 295 kN, a 32 mm bar at about 480 kN and a 40 mm bar at about 755 kN. The grips must also fit the bar: the WE-300B grips round specimens of 10 to 32 mm, the WE-600B 13 to 40 mm and the WE-1000B 14 to 45 mm.

Most of the machines on this page are specified for 380 V three-phase at 50 Hz, with a 220 V option on many models; South African three-phase supply is nominally 400 V. The OBRK-2000 runs on 220 V, 50 Hz. Confirm your supply with Ecotao before ordering so the machine is configured correctly.

The most commonly referenced methods are SANS 5863 (compressive strength of hardened concrete), SANS 5864 (flexural strength of hardened concrete), SANS 6253 (tensile splitting strength of concrete) and SANS 50196-1, the South African adoption of EN 196-1, for cement strength on 40 × 40 × 160 mm prisms. Reinforcing bar is specified under SANS 920. Each method sets the specimen size and loading rate, so choose a machine that can hold the rate your method requires.

Yes. Ecotao supplies material testing equipment throughout South Africa and to Namibia, Botswana, Zimbabwe, Mozambique, Lesotho and Eswatini. Heavy-duty compression machines weigh from about 400 kg to 2700 kg, so ask Ecotao about delivery, offloading and floor requirements when you request a quote.