Abstract
It is a well-known fact that either pellets or granules used in sandblasting operations for cleaning/finishing metal surfaces of any kind, are subject over time to processes of either splitting or wear of the surface, thus diminishing their operational features, such as, for instance: the angularity and dimension. When being used in sandblasting operations, the granule size fractions that have lost their capacity of finishing surfaces are being sorted by sifting and eliminated. In industrial conditions, where very large surfaces are being sandblasted, the grit turns into a major problem, since it often requires large warehouse surface areas for storage. In that sense, this paperwork presents experimental data regarding the worn grit fractions management by using it in asphalt mixtures, conferring, beside an economic benefit, also that of environment protection, since those lightweight fractions oftentimes form very polluting air floating powder. By eliminating those fractions that are reusable in the process of sandblasting, on the remaining sort resulted from sifting through the 1.0 mm strainer granulation and bitumen behaviour studies were carried out. The analysis of proposed asphalt mixtures, holding a certain percentage of grit, highlighted the fact that the latter, by both the 0.4- 0.1 mm granule size and by the floatable particles of less than 0.2 mm granule size, allow for the replacement of natural quartz sand. The physical-mechanical features of studied mixtures were established on cylindrical probes made of bitumen, in which smashed silicone stone chippings were mixed, within standard required range of granule size, crushing sand and worn grit, in very well controlled mixing proportions. the results were compared to those derived from standard samples made of solely quartz crushing sand, alongside the other components that make up type BA8 asphalt mixtures, of a mere 6.5% bitumen of a 50/70 proportion, according to local standards. By comparing the two asphalt mixture type features (standard and experimental), it allowed for highlighting that worn grit may be very successfully used instead of crushed sand. Keywords: grit, asphalt mixture, recycling, exploitation, environmental protection