Develop Guidelines for Effective Prime Coats

Project Description

The purpose of a prime coat is to increase the effectiveness of surface treatments by strengthening the base and protecting it from wet weather, reducing the drying rate of the base, and promoting the bonding of the base to the asphalt pavement layer. The purpose of this research effort was to evaluate the effectiveness of prime coats to determine which combinations of methods and materials provide the greatest benefit. Researchers used extensive surveys with TxDOT personnel, conducted a worldwide literature review and developed and modified testing procedures. In part, their work concluded that the best technique for promoting good bonding is to mix the prime coat into the top inch of the roadway base. Through the research, they developed guidelines for the selection, application and evaluation of prime coats. These guidelines address all elements of base priming, including: base surface preparation, prime coat design, alternative priming methods, material selection criteria, proper application methods and quantities, curing procedures, construction control and quality assurance, and safety precautions. The researchers recommend that the guidelines be published as a handbook for use by both TxDOT personnel and contractors. They also recommend workshops to ensure thorough understanding and consistent application of the guidelines statewide. Researchers produced a Powerpoint presentation and a series of video segments to serve as instructional aids for workshops and for use on TxDOT's website.

Project Publications

Effective Prime Coats for Compacted Pavement Bases 0-5635-1

Guidelines for Selection, Application, and Evaluation of Prime Coats 0-5635-P2

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