等级道路 meaning in Chinese

classified highway
classified road

Abstract : through deep vacuum distillation , the 90 high grade road asphalt meeting the standard of sinopec and the esso standard and the 70 high grade road asphalt meeting the standard of the ministry of communications and the national standard were directly produced with high gum and high asphalt saudi arab middle crude
文摘:大连西太平洋石油化工有限公司采用减压深拔技术，加工胶质、沥青质含量高的沙特阿拉伯中质原油，直接生产出符合中石化标准及埃索标准的90号等级道路沥青及符合交通部标准、国家标准的70号高等级道路沥青产品，为今后生产高等级道路沥青积累了有益的经验。