EVALUATION OF PARTICLE SHAPE AND TEXTURE: MANUFACTURED VERSUS NATURAL SANDS

摘要: Many highway agencies now limit the amount of natural sand in hot mix asphalt (HMA) when used on heavy-duty pavements to minimize rutting. This procedure is usually accomplished by generically specifying maximum allowable percentage sand. Generally, sands tend be rounded whereas manufactured angular. However, there are some that subangular rather than rounded. Also, or crushed can subrounded completely There a definite need quantify shape and texture fine aggregate so it specified rational basis generically. Fine aggregates (8 10 sands) different mineralogical compositions were sampled from various sources Pennsylvania. Particle data obtained using ASTM D3398, two proposed methods National Aggregate Association (NAA). On particle index value 14 appears divide sands, therefore, for specification purposes. because each sieve size fraction needs tested individually results combined, current D3398 test procedures too time consuming. indicate only major its has fairly good correlation with average index. Moreover, both NAA Methods A B show correlations (R-squared equals 0.97) method. These straightforward less Equations needed compute weighted-average values described.