A sand-asphalt-sulfur (SAS) mix has been considered by many as an alternative to asphalt concrete mixes. One of the drawbacks. of SAS mixes is their high air void content. The results of a study on the effect of flyash filler on the air voids and other engineering properties of SAS mixes are presented. It was found that compared with SAS mixes, sand-asphalt-flyash-sulfur mixes have, in general, higher stability values and lower air voids. The static tensile and flexural properties have been studied for some mixes. The flexural strength and fatigue life under repeated loading of some selected mixes generally have been found to be higher than those of an asphalt concrete mix.

Sand-asphalt-sulfur (SAS) mixes have been suggested by investigators (1, 2) as a possible alternative to asphalt concrete mixes, particularly in areas where there exists a shortage of good-quality coarse aggregates. It has been found that SAS mixes in general possess satisfactory stability values. However, one of the drawbacks of SAS mixes is that they have very high air void contents compared with asphalt concrete mixes. Most of the investigators observe that this high air void content in a SAS mix is not harmful because of its low permeability characteristics (3-5). However, one of the ways in which the air voids may be decreased is by the addition of a suitable filler. Such an addition may give rise to an increase in strength characteristics too. This paper presents the results of an investigation of the effect of adding flyash dust to a SAS mix, resulting in a sand-asphalt-flyash-sulfur (SAF AS) mix. The disposal of flyash is a major problem in most thermal power plants; hence, the use of flyash in paving mixes may contribute significantly to solving this problem.