Automatic Triple-Unit Temperature-Controlled Creep Triaxial Apparatus

1. Description

This equipment is a Fully Automatic Triple-Unit Temperature-Controlled Creep Triaxial Apparatus (BTU-TCA-3T). It is an advanced geotechnical testing system integratingtemperature control, triaxial shearing, and creep testing. It adopts adual-chamber temperature-controlled pressure celland provides precise temperature control from -30℃ to +100℃, with bothstrain-controlled and stress-controlledoperation modes. The system includes three independent testing units (triple-unit) that allow simultaneous testing of multiple specimens for creep or triaxial tests. The software covers conventional triaxial, k0 consolidation, stress path, andtriaxial creepmodules, making it suitable for long-term deformation and temperature‑coupled studies.

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2. Test Standards

• ASTM D7181(Consolidated Drained Triaxial Compression Test)
• ASTM D4767(Consolidated Undrained Triaxial Compression Test)
• ASTM D2850(Unconsolidated Undrained Triaxial Compression Test)
• ASTM D7078(Creep test methods)
• BS 1377(British Standards for soil testing)
• SL 237-1999(Chinese specification for soil testing)

Temperature control and creep aspects may follow relevant research specifications or custom procedures.

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3. Specification (Parameter )

Software modules: Data acquisition, back pressure saturation, UU, CU, CD, k0 consolidation, stress path, triaxial creep

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4. Detail (technical details)

• Dual-chamber temperature-controlled pressure cell: Dual-chamber design with circulating temperature-control liquid, reducing interference with cell pressure and volume change measurements.
• Temperature sensor embedded at specimen base: Measures the actual internal temperature of the specimen rather than ambient temperature, with accuracy ±0.1℃.
• Wide temperature control range: -30℃ ~ +100℃, covering frozen soil, high-temperature geotechnics, energy piles, etc.
• High-precision loading system: Shearing speed as low as 0.00001 mm/min, suitable for long-term creep tests; maximum axial force 30 kN.
• Dual control modes: Supports bothstrain-controlled(constant rate shearing) andstress-controlled(constant load application) modes – the latter being essential for creep tests.
• High-resolution drainage/volume change measurement: Resolution 0.001 ml, capacity ≥200 ml, suitable for detecting small volume changes during long-term creep.
• Triple-unit structure: Three independent pressure cells and loading axes, allowing simultaneous testing of three different specimens (same or different conditions), significantly improving testing efficiency.

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5. Application

• Long-term settlement studies of soft soils: Simulating creep behaviour of soft soils under constant loading
• Frozen soil and cold-region engineering: Creep and strength characteristics at sub-zero temperatures (-30℃)
• Energy piles and ground source heat pumps: Effect of temperature cycles on soil creep around piles
• Nuclear waste repositories: Long-term deformation of buffer materials under temperature‑stress coupling
• High-filled embankments and dams: Deformation prediction under long-term loading
• Constitutive model parameter calibration: Determining parameters for creep and rheological models
• Teaching and research: Complex stress‑temperature‑time coupled testing

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6. Advantages

• Wide temperature control range(-30℃ ~ +100℃): covers frozen soil, high temperature, and ambient temperature conditions
• True specimen temperature measurement: Sensor embedded at specimen base for more accurate temperature control
• Dual control modes(strain + stress): meets both creep and conventional triaxial requirements
• Ultra-low shearing speed capability: 0.00001 mm/min, suitable for long-term rheology
• High-resolution drainage/volume change: 0.001 ml, suitable for detecting small volume changes
• Triple independent testing units: Three systems independently controlled, high efficiency, suitable for comparative tests
• Modular software: Includes advanced modules such as k0, stress path, and creep
• Software: Convenient

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8. What To Choose (selection guide)

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9. Process Flow

• Specimen preparation→ Prepare saturated/unsaturated soil specimens of Ø39.1mm×80mm or Ø61.8mm×125mm
• Mount pressure cell→ Install specimen in the dual-chamber temperature-controlled pressure cell; connect cell pressure, back pressure, and pore pressure lines; embed temperature sensor at base
• Set temperature→ Set target temperature (e.g., -20℃, +5℃, +60℃); wait for temperature to stabilize (accuracy ±0.1℃)
• Saturation and consolidation→ Back pressure saturation → B-check → Isotropic consolidation or k0 consolidation (optional)
• Creep stage (stress-controlled)→ Apply constant axial stress (or constant cell pressure/deviatoric stress); record axial deformation and volume change over time
• Shearing stage (strain-controlled, optional)→ After creep, shear at constant rate to failure; determine residual strength
• Data acquisition→ Long-term monitoring (hours to months): axial force/stress, displacement/strain, volume change, drainage, pore pressure, temperature
• Parallel multi‑specimen testing→ The triple-unit system can perform creep tests on three different specimens under different temperature/stress conditions simultaneously
• Post-processing→ Plot creep curves (strain vs. time), isochronous stress-strain curves, creep rate curves, etc.; determine creep parameters (e.g., secondary creep rate, creep failure threshold)
• Report output→ Automatically generate test tables and curves; support export and printing

260 workers, 25000 ㎡ non-dust workshop, 16 years experience, SGS & INTERTEK certificated, one hour reach Tianjin port, this is how we keep good quality and competitive prices for global valued customers.

Our main products cover Universal testing machine, Compression testing machine, Soil,Concrete,Cement Mortar,Aggregates Rocks, Asphalt Bitumen, NDT,Pavement ,Paint,Ceramics,Drilling Fluids, Geotextiles, Textiles, Environmental,General Equipment.BTUTEST is exporting its products to more than 60 countries by offering its services through its authorized distributors and representatives.

Our main customers are private and research testing laboratories, road and general contractors, concrete and cement manufacturers, asphalt manufacturers, government authorities, ministries, engineers, consultants and re-seller. We also cooperate with accredited research centers and the most important universities in the world.we can supply more top quality product and service for more customer’s.