Temperature Instruments for the Asphalt Industry

At the heart of asphalt production are asphalt mixing plants where aggregates are heated and mixed with bitumen and other adhesive substances to create hot mix asphalt (HMA). The specific requirements of the mix, defined by the contractor, dictate the quantity and nature of the aggregates, which can range from single-sized material to various sizes of fine and coarse particles.

Tel-Tru offers reliable and durable temperature monitoring instruments  that help asphalt plants produce the highest quality mixes and avoid temperature measurement errors. Before and during asphalt production, laboratory testing is essential. The optimal composition, mix volumetrics, and aggregate gradation of the asphalt are all developed in the laboratory, along with the air and mineral aggregate voids.

Constant testing of both HMA and warm mix asphalt (WMA) is crucial to ensure the highest quality and the appropriate composition of the mix. Regular test batches should be pulled from the production process for testing in accordance with customer specifications and state guidelines. Results from these tests are readily available for pre-approval and follow-up audits, ensuring compliance and quality control.

Transporting asphalt from the plant to the application site presents significant challenges due to potential temperature loss. Factors such as air temperature, rain, wind, and haul length can affect the characteristics and temperature of the asphalt load. To minimize cooling during transport, specific measures like insulating truck beds, minimizing haul distances, and using tarps to cover the load can be employed.

Tel-Tru thermometers are essential tools for monitoring and confirming that the asphalt maintains the optimal temperature throughout its journey. Distance, travel time, and wait time at the job site all impact the quality of the paving project. If the HMA sits for too long before being dumped into the paver, it may fall out of the acceptable temperature range, compromising the quality. Tel-Tru’s testing thermometers ensure that the material is at the correct temperature for paving and rolling.

When it comes to paving, the temperature of the screed and the ground must be within acceptable ranges to achieve quality results. Tel-Tru’s Tel-Fast infrared (IR) thermometers are ideal for performing these critical temperature checks. For sealing and repairs, maintaining the optimum temperature of the hot tar in the tank is essential for proper flow, adhesion, and safety.

Tel-Tru provides accurate temperature monitoring instruments to ensure the HMA temperature is properly maintained throughout the project. This accuracy helps prevent out-of-specification HMA, which can lead to unnecessary rework, replacement costs, or costly project work stoppages.

The final temperature check of the asphalt pad should be performed just before the roller compacts it. Rolling must be completed before the surface temperature of the mix falls below 240°F. Tel-Tru’s general and spot check testing thermometers deliver the reliability and accuracy needed for this crucial final step.

Industry best practices advocate for measuring the temperature of the asphalt pad before every stage of the rolling process to ensure proper compaction. Logging this data not only helps achieve optimal results but also provides proof of work quality and process effectiveness.