There are high costs in paving services in the Brazilian Amazon region, mainly due to the lack of coarse aggregate--pebble or crushed stone---in addition to the elevated rainfall and the high geographic expanse of the...There are high costs in paving services in the Brazilian Amazon region, mainly due to the lack of coarse aggregate--pebble or crushed stone---in addition to the elevated rainfall and the high geographic expanse of the region. The natural coarse aggregate often used in that region is extracted from the riverbeds a distance no less than 500 km from the major cities. In search of a technical, economic and environmental alternative to work around the problem, using an unconventional material that could replace the pebble or crushed stone, a study was carded out on natural clay, considered an abundant mineral resource, especially in the Amazon Basin. A manual mill was used for this purpose, consisting of four square metal nozzles of dimensions 12.7 mm, 9.5 mm, 4.8 mm and 2.0 mm, used for moulding the wet ribbon clay. After that, firing was carried out at temperatures of 780℃, 850℃, 950℃, 1,050 ℃ to 1,150℃ A comparative analysis between conventional hot mixed asphalt--using pebble as coarse aggregate--and that employing synthetic aggregate was made. In a general way, hot mixed asphalt using synthetic aggregate showed excellent results of physical and mechanical properties, in relation to the conventional mixture, mainly at higher temperature of aggregate calcination.展开更多
文摘There are high costs in paving services in the Brazilian Amazon region, mainly due to the lack of coarse aggregate--pebble or crushed stone---in addition to the elevated rainfall and the high geographic expanse of the region. The natural coarse aggregate often used in that region is extracted from the riverbeds a distance no less than 500 km from the major cities. In search of a technical, economic and environmental alternative to work around the problem, using an unconventional material that could replace the pebble or crushed stone, a study was carded out on natural clay, considered an abundant mineral resource, especially in the Amazon Basin. A manual mill was used for this purpose, consisting of four square metal nozzles of dimensions 12.7 mm, 9.5 mm, 4.8 mm and 2.0 mm, used for moulding the wet ribbon clay. After that, firing was carried out at temperatures of 780℃, 850℃, 950℃, 1,050 ℃ to 1,150℃ A comparative analysis between conventional hot mixed asphalt--using pebble as coarse aggregate--and that employing synthetic aggregate was made. In a general way, hot mixed asphalt using synthetic aggregate showed excellent results of physical and mechanical properties, in relation to the conventional mixture, mainly at higher temperature of aggregate calcination.
