Experimental investigation on factors affecting the bulking of aggregate quarry products

Abstract

Aggregate quarry products have long been essential to the construction sector. These aggregate products are produced by blasting the in-situ rock at quarries and subjecting it to primary and secondary crushing. There is a volume change when converting in-situ rock volume into the product volume because of a phenomenon called bulking, which happens when the rock is broken down into smaller particle sizes. Air spaces develop between the rock particles during blasting and crushing activities increasing the volume of quarry products. This study aims to investigate the effect of moisture content, particle size and rock type on bulking of aggregate quarry products. Quarry products (Dust, Chip, ¾” metal ,1.5” metal and ABC [Aggregate-Base-Course]) were collected systematically from six quarries and the bulking factor was tested in different moisture conditions. Furthermore, the mineralogy and specific gravity of collected samples were determined by visual observations and pycnometer method respectively. This study identified that quarry dust and the ABC product exhibit significant deviations in bulking factor with changing moisture content, whereas other products (Chip, ¾” metal and 1.5” metal) exhibit no discernible deviations in bulking factor with increasing moisture content and identified that mineralogy almost no effect to the bulking factor since study area contains similar kind of mineralogy.