INNOVATIONS IN OKLAHOMA FOAMIX DESIGN PROCEDURES

Little attempt has been made in Oklahoma to investigate foamed asphalt mixes or to take advantage of these mixes for road construction purposes. To demonstrate the efficacy and applicability of this type of asphalt mix, a study of factors that affect fine aggregate-foamed asphalt mixtures formulated from materials indigenous to the state was undertaken. In addition to verifying the effects of the amount of fines (percentage of aggregate material passing the No. 200 sieve), mixing moisture content, asphalt content, and curing condition on foamix properties as reported by previous investigators, this study introduced two unique investigative concepts: (a) the use of an aggregate's "particle index" along with the percentage passing the No. 200 sieve to predict its performance in a foamix and (b) the use of a multilinear regression model or equation for determining the optimum premolding moisture content for a foamix. Although only a part of the original investigation, these two aspects of the study are considered directly applicable to foamix mix design procedures. The "particle index" (a measure of angularity and surface texture of aggregate particles) proved to be an excellent indicator of the suitability of marginal quality aggregates for foamixing. By using the predictive multilinear regression equation, the optimum premolding moisture content for a foamix can be ascertained without extensive laboratory testing.