Bending Beam Rheometers measure the flexural creep stiffness of asphalt binder at cold temperatures (ambient to -40°C) to predict low-temperature thermal cracking of asphalt pavements. Special molds are used to form small asphalt beam samples for testing. The three point bend apparatus is easily removed and reinstalled in the base unit for convenient sample preparation and loading. Deflection of the beam specimen is measured and recorded as a constant load is applied. Load, displacement, and bath temperature are displayed in tabular and graphic form in real time. The stiffness value is calculated at the lowest temperature anticipated for the region. A fluid bath controls temperature the Ethylene Glycol/Water/Methanol mixture down to -40°C (-40°F). Process temperature is controlled and monitored by two independent platinum RTD temperature transducers to maintain temperature stability. Both BBR models fully comply with ASTM/AASHTO requirements. A source of clean, dry, compressed air at 50 PSIG minimum must be provided by the user.
The Bending Beam Rheometers is a proven and reliable model constructed of stainless steel and durable, high-strength polymer components. The unit uses an air bearing system to assure reliable loading with accurate and repeatable results. A linear variable displacement transducer (LVDT) with a range of 6.35mm and accuracy to ±2µm measures deflection. The temperature-compensating 500g load cell with mechanical overload protection ensures accurate load results. Safe, rapid cooling of the test fluid is provided by the mechanical refrigeration system.
The Bending Beam Rheometer includes a Computer with pre-loaded control, acquisition, and analysis software, five aluminum specimen Molds with mylar strips, a Calibration Kit with required weights, and Confidence Beam. Calibrated test weights and a certified LVDT NIST-traceable standard are provided with each system. The easy-to-use software allows daily verification and periodic calibration of load cell, LVDT, and RTD transducers.
Meets Test Methods:
ASTM D 6648