MSU Technologies

Asphalt Foam Collapse Test (AFCT)

Introduction

Asphalt producers and users in the U.S. have historically used Hot Mix Asphalt Concrete (HMAC), which is required to be mixed, distributed and spread at approximately 300 degrees F. With an added emphasis on environmental and energy concerns, Warm Mix Asphalt (WMA) has become an option in recent years. Since its first trial use in 2004, WMA has taken over approximately 13% of the U.S. asphalt market. By increasing the workability (i.e. decreasing viscosity) of the asphalt when delivered to the site, WMA is able to be batched and delivered at significantly lower temperatures. One method to increase the workability is to use foaming technology to introduce steam bubbles into the binder before the aggregate is added to the mixture. These bubbles, depending upon their quantity and size, increase the ability of the binder to coat the aggregate. The amount and size of steam bubbles produced is dependent on the method used to generate this workability, as well as the air pressure and the water content of the mixture. The quality of the foam is measured according to certain parameters.

Description of Technology

This technology proposes a mechanical system to produce a graph and subsequent WMA quality parameters. After the graph is produced and analyzed, the WMA parameters can be optimized in order to greatly improved WMA quality or coincide with future state regulation regarding WMA quality.

Key Benefits

Optimization-Allows asphalt batch plants to optimize foaming operations
Customization-Consumers would be afforded the option of optimizing their WMA usage depending on different important WMA quality parameters

Applications