Presses for laboratory mechanical soil testing: CBR and Marshall, consolidation, direct shear, and static and dynamic triaxial, with the ABNT, DNIT and ASTM standards for each test.
The Biopdi manufactures the presses for mechanical soil testing: the CBR / Marshall test press for the California Bearing Ratio and the stability of asphalt mixtures, the consolidation press for settlement, the direct shear press for cohesion and friction angle, and the triaxial testing system, static for UU, CU and CD tests and dynamic for the resilient modulus and permanent deformation of pavements.
The presses are manufactured in São Carlos (SP), Brazil, in manual and automatic versions; the automatic versions have their own data acquisition and software. The table below shows which equipment runs each test and under which standard.
Equipment lines
Four equipment lines, each with its own specifications page.
01
Bearing capacity of subgrade, subbase and base, and stability of asphalt mixtures. A 5,000 kgf (49 kN) press, available in manual and automatic electric versions, with Marshall accessories: compaction hammer, mold and compactor.
02
Settlement and coefficient of consolidation. Lever-arm press with dial indicator, or a 50 kN electric version built on the same frame as the CBR press, with load control.
03
Drained cohesion and friction angle. Manual, semi-automatic and automatic electric models; the electric version has 10 kN capacity, speeds from 0.0001 to 20 mm/min, 60 and 100 mm shear boxes and a touchscreen.
04
Static for UU, CU and CD tests, and dynamic for resilient modulus and permanent deformation of pavements, in basic and automatic versions.
Guide
The test, what it measures, the standard commonly used in Brazil and the Biopdi press that runs it.
| Test | What it measures | Standard | Biopdi equipment |
|---|---|---|---|
| CBR (California Bearing Ratio) | Bearing capacity of subgrade, subbase and base, and swelling | ABNT NBR 9895:2025; DNIT 172/2016-ME | CBR / Marshall Test Press |
| Marshall | Stability and flow of the asphalt mixture | DNIT 447/2024-ME | CBR / Marshall Test Press |
| Consolidation (oedometer) | Settlement, compression index, preconsolidation stress and coefficient of consolidation | ABNT NBR 16853:2020; ASTM D2435 | Consolidation apparatus |
| Direct shear | Drained cohesion c' and friction angle φ' | ASTM D3080/D3080M | Direct shear apparatus |
| Unconfined compression (UC) | Unconfined compressive strength of cohesive soils | ASTM D2166 | Static triaxial testing system |
| Triaxial UU, CU and CD | Shear strength with control of drainage, pore pressure and stress path | ASTM D2850; ASTM D4767; ASTM D7181 | Static triaxial testing system |
| Resilient modulus of soils | Stiffness under repeated loading, for pavement design | DNIT 134/2018-ME | Dynamic triaxial testing system |
| Permanent deformation | Accumulated soil rutting under repeated loading | DNIT 179/2018-IE | Dynamic triaxial testing system |
| Resilient modulus of asphalt mixtures | Stiffness by indirect tension (diametral compression) | DNIT 135/2018-ME | Dynamic triaxial testing system with diametral compression fixture |
| Resilient modulus of stabilized materials | Stiffness of soil-cement and cement-treated crushed stone base | DNIT 181/2018-ME | Dynamic triaxial testing system with DNIT 181 MR fixture |
Proctor compaction, particle size distribution and Atterberg limits characterize the soil before these tests and define the moisture content and density of the test specimens.
The type of project defines which soil parameters the design needs.
CBR selects and controls subgrade, subbase and base materials; resilient modulus and permanent deformation feed mechanistic-empirical pavement design; the Marshall test is used for asphalt concrete mix design and control.
Cohesion and friction angle are inputs for bearing capacity, slope stability and earth pressure calculations. The direct shear test gives drained c' and φ'; the triaxial test controls drainage and measures pore pressure.
The consolidation test measures how much and how fast the soil settles under the load of the embankment or structure: compression index, preconsolidation stress and coefficient of consolidation.
University soil mechanics laboratories use the same presses for hands-on classes and for research, with data acquisition and software that record the test for later analysis.
Guides with the procedure, calculations and standards for each test.
The most frequent questions about soil testing equipment.
Characterization tests (particle size distribution, Atterberg limits, specific gravity and Proctor compaction) and mechanical tests: CBR, consolidation, direct shear, triaxial (UU, CU and CD), unconfined compression and, for pavements, resilient modulus and permanent deformation. Biopdi manufactures the presses for the mechanical tests.
The 5,000 kgf (49 kN) CBR / Marshall test press, manual or electric automatic; the consolidation press; the direct shear press, in manual, semi-automatic and electric automatic versions; and the triaxial press, static 50 kN and dynamic 20 kN, in basic and automatic versions.
Yes. The PCM-5k electric automatic press, rated at 50 kN, runs all three tests. Changing the fixture changes the test: the penetration piston for CBR, the compression mold for Marshall and the 2" or 3" oedometer cell for consolidation.
In the direct shear test, the split shear box imposes the failure plane and the test is drained. It is simpler and faster. In the triaxial test, the cylindrical specimen fails along its weakest plane, drainage is controlled and pore pressure is measured. This allows undrained tests (UU and CU) and effective stress analysis.
The CBR press for subgrade, subbase and base materials; the dynamic triaxial press for resilient modulus (DNIT 134/2018-ME, a Brazilian highway standard) and permanent deformation (DNIT 179/2018-IE); and the Marshall press, or the indirect tensile (diametral compression) fixture on the dynamic triaxial press, for asphalt mixtures.
No. Biopdi manufactures the equipment so that the laboratory can run the tests itself. We install it, train the team and provide technical support from São Carlos (SP), Brazil.
The tests and standards the laboratory needs to meet, the type of soil or material, the specimen sizes and whether the press should be manual or automatic. With this, the proposal includes the matching press, fixtures and software.
Price, commercial terms and lead time for soil testing presses. Tell us which tests and standards your laboratory must meet and we will recommend the configuration.
A proposal covering capacity, fixtures and the standards met, not just the price.
Press, fixtures and software selected based on the tests and standards of your laboratory.
Installation, training and technical support provided by the people who designed the machine.
