COMPASS is computer-based guidelines for job-specific optimization of paving concrete. It is currently under review by the Federal Highway Administration (FHWA) and is not an official set of guidelines, yet. If accepted by FHWA, it will result in a truly performance-driven mix design system.
Who uses COMPASS and why?
COMPASS is intended to be an ideal tool for pavement engineers, materials engineers, concrete mix designers, researchers, and concrete suppliers. COMPASS reduces the stress of choosing the best mix design that will meet job specific requirements, is easy to use, and saves time which is money in the pavement construction business.
How does COMPASS work?
The COMPASS software consists of four modules: Mix Expert, Aggregate Gradation, Mix Proportioning, and Mix Optimization. Each module is designed to function as an independent tool. Used together in a progressive manner, the system of modules results in a comprehensive optimization tool.
The Mix Expert module consists of a knowledge-base used as a “first cut” in optimizing a mix. It identifies a performance criteria and subset of materials that should be considered to meet those criteria. Computer-based guidelines (software) employing numerous models will then reduce these materials further, identifying the “best” mix for the job.
Optimization begins with a desired set of criteria (targets). In order to meet these targets, the user must first define under what job-specific conditions the pavement will be constructed (the design, environment, and construction). They must also define what materials are available to them, and possibly what the cost of the materials will be. As a result of this information, an optimum mixture can be determined using a systems approach.
In the end, the software can be used in three modes. First, in a planning mode that allows decisions about the best mix to be made, well in advance of the placement. The second mode will probably be the most common, allowing the user to derive the project mix based on knowledge of the specific materials available to them. Finally, a third mode will allow the user to assess the impact of changes in their mix as they impact the behavior and performance of the concrete pavement.
How can you try COMPASS?
COMPASS is NOT an official set of guidelines—the tool is still under review by FHWA with an official release pending. However, we encourage YOU to download an unofficial copy of COMPASS for trial purposes and provide any feedback.
Download the COMPASS User’s Guide.
If you have any questions or general comments please feel free to contact us.