A Sure-Fire Way to Predict Pavement Quality
What’s one of the best ways to predict pavement quality? The Rolling Thin Film Oven (RTFO) test is a good place to start! The properties of the binder in Hot Mix Asphalt (HMA) change and undergo significant aging during handling, mixing and paving operations, so it’s important to ensure that the end product still meets the design requirements when placed. A properly designed and installed asphalt pavement will withstand traffic and weather conditions for many years to come. In this blog post we’ll cover the importance of measuring these asphalt binder characteristics and the best equipment to use.
Rolling Thin Film Ovens measure the effect of heat and air on a moving film of hot mix asphalt binder, simulating short-term aging that occurs during production and paving operations. This is important for investigating and predicting early age HMA pavement behavior and distress.
A sample of asphalt binder is heated and dispensed into special glass specimen bottles. The bottles are mounted horizontally in a carousel in the oven, where they are rotated at 15rpm for 85 minutes as a jet of 325°F heated air is directed into them. At the completion of the RTFO test, mass change, viscosity and other rheological properties are measured and compared to values from unheated samples. For a complete description of the procedure, reference AASHTO T 240 and ASTM D 2872: Effect of Heat and Air on a Moving Film of Asphalt.
RTFO’s offer several benefits that traditional thin-film ovens do not provide. The carousel continuously exposes heat and air flow with a consistent rolling action, keeping asphalt binder modifiers dispersed. Additionally, RTFO’s:
- Eliminate surface skin, which can inhibit aging of asphalt binder
- Expedite test times, taking just 85 minutes on average
- Improve test accuracy and repeatability
- Offer simple operation with minimal training required
What Gilson’s Cooking Up
Gilson’s new MO-36 Rolling Thin Film Oven, manufactured in cooperation with ATS is complete with an advanced design, durable construction and reliable accuracy to easily measure the effect of heat and air on asphalt binder. Precision components are controlled for precise, repeatable results and straightforward operation with minimal training required. A built-in timer controls test times and temperature control is easily programmed for temperatures up to 246°C (475°F), promoting uniformity and repeatability. A uniquely designed carousel is faster and easier to load and eliminates scratched and damaged bottles. The rugged and accurate Gilson RTFO is CE-marked, Made in the USA and meets all test method specifications while exceeding recovery time requirements.