Moisture measurement in asphalt

With increasing costs in raw materials, asphalt manufacturers are looking at ways to reduce costs while continuing to produce a consistent quality product. On-line moisture measurement in asphalt production is a cost effective method of reducing costs without affecting quality.

Benefits

  • Monitor and ensure the efficiency of burners
  • Reduce costs by maximising output and more efficient use of materials
  • Improve quality, by ensuring consistent gradation of aggregates
  • Reduce cost of poor quality by reducing the amount of remedial action/rework

Finer materials "hold" more moisture than coarser materials and increased moisture levels from factors such as rain will affect their weight. For manufacturers that grade by weight, this will lead to an incorrect ratio of combined materials. Without moisture control, the relative proportion of the finer materials will fall.  This causes a reduction in density which will affect the quality of the finished product.

By installing moisture measurement sensors underneath the aggregate bins or on the cold feed belts, the correct moisture levels of each aggregate can be accurately measured and the ratio of materials corrected in real time.  A further benefit is that the amount of energy required by the burners to dry the aggregate can also be calculated and adjusted accordingly. This can lead to a reduction in fuel costs and increased burner efficiency.

Asphalt producers are currently benefiting by installing the Hydro-Probe microwave sensor from Hydronix. The sensor is cost effective, rugged, simple to integrate, install and configure and has a very low maintenance overhead.