Tuofeng TFW-239 Intelligent Rock Bolt Pull-Out Tester

Overview

The Tuofeng TFW-239 Intelligent Rock Bolt Pull-Out Tester is a high-precision electromechanical universal testing machine engineered specifically for geotechnical anchorage verification and structural integrity assessment in civil engineering, mining, tunneling, and underground construction applications. Unlike general-purpose tensile testers, the TFW-239 integrates real-time load-displacement synchronization, programmable pull-out profiles, and anchor-specific test protocols—including controlled displacement ramping, dwell-hold sequences, and cyclic loading—designed to replicate in-situ stress conditions on rock bolts, soil nails, and ground anchors. Its force measurement architecture complies with ISO 7500-1 Class 0.5 and GB/T 16491-2008, ensuring metrological traceability for third-party certification and regulatory reporting. The system operates on a closed-loop control principle, where load cell feedback dynamically adjusts servo motor torque to maintain target force or displacement trajectories within ±0.005% accuracy—critical for evaluating bond strength degradation, grout interface failure modes, and creep behavior under sustained load.

Key Features

• Integrated rock bolt-specific test methodology: pre-configured standards for ASTM D4435 (rock bolt pull-out), EN 1537 (ground anchors), and GB/T 32872 (mining support systems)
• High-stiffness frame with 600 mm clear test width and 800 mm vertical stroke—accommodates full-length 3–6 m rock bolts with standard or custom anchorage fixtures
• Constant-resolution force sensing (1:500,000) across full 239 kN range—eliminates range-switching artifacts during low-force debonding onset detection
• Dual-speed motorized crosshead: rapid positioning (up to 500 mm/min) and micro-adjustment mode (0.001 mm/min) for precise preload application and slippage threshold identification
• Redundant safety architecture: hardware-based emergency stop, software-enforced load limits, mechanical overload cutoff at 110% FS, and optical end-of-stroke detection
• Modular extensometry support: compatibility with both clip-on axial extensometers (for strain measurement on bolt shank) and non-contact video extensometers (for grout-concrete interface tracking)

Sample Compatibility & Compliance

The TFW-239 accepts standard rock bolt configurations—including fully grouted, end-anchored, friction-type, and resin-anchored systems—with customizable jaw geometries (V-groove, serrated, or hydraulic clamping). It supports test specimens per ASTM D4435 Annex A (concrete block pull-out), ISO 22262 (anchor performance classification), and Chinese national standard CJJ/T 219 (urban tunnel anchor acceptance criteria). All mechanical and electrical subsystems meet CE Machinery Directive 2006/42/EC requirements. Calibration certificates are issued traceable to NIM (National Institute of Metrology, China) and include uncertainty budgets per ISO/IEC 17025. For regulated environments, optional 21 CFR Part 11 compliance packages provide electronic signature enforcement, audit trail generation, and user access tiering.

Software & Data Management

Tuofeng’s TensilePro v5.2 software provides ISO 17025-aligned test execution and reporting. It enables multi-step test programs (e.g., “pre-load → hold → ramp → dwell → unload”) with real-time parameter validation. Raw data streams—load, displacement, time, and optional strain—are recorded at ≥1 kHz sampling rate and stored in HDF5 format for long-term archival integrity. Reports auto-generate per ASTM E2382 (pull-out test report structure), including bond strength (MPa), displacement at peak load (mm), residual load after unloading, and load-slip curve derivatives. Export options include CSV, PDF/A-2, and XML for LIMS integration. Audit trails log all user actions, parameter changes, and calibration events with timestamps and operator IDs—fully configurable for GLP/GMP laboratory workflows.

Applications

• Quantification of bond strength between threaded steel bars and cementitious grout in mine roof support systems
• Verification of anchorage capacity for post-tensioned ground anchors in slope stabilization projects
• Evaluation of corrosion-influenced bond degradation in aging infrastructure (e.g., subway tunnels, hydropower caverns)
• Development testing of novel anchor geometries (e.g., ribbed, helical, or composite FRP bolts)
• Quality assurance of factory-produced grouted anchor assemblies prior to site installation
• Research into temperature- and moisture-dependent bond mechanics in deep geological repositories

FAQ

Does the TFW-239 comply with ASTM D4435 for rock bolt pull-out testing?
Yes—the system includes pre-loaded test templates, force ramp rate controls, and displacement monitoring thresholds specified in ASTM D4435 Annex A.

Can the machine perform cyclic pull-out tests to simulate seismic loading?
Yes—TensilePro v5.2 supports up to 999 cycles with programmable amplitude, frequency, and dwell periods; data is synchronized across all channels.

Is third-party calibration certification included with delivery?
Each unit ships with a NIM-traceable calibration certificate covering force, displacement, and speed axes, valid for 12 months.

What is the maximum specimen length supported without modification?
The standard configuration accommodates specimens up to 3.2 m; extended columns (up to 6 m) are available as factory-installed options.

How is software validation handled for regulated laboratories?
Tuofeng provides IQ/OQ documentation, 21 CFR Part 11 readiness assessment reports, and on-site validation support upon request.