Highway engineering & construction

The ’purpose of this study is to investigate the use of lowquality aggregates (LQA) of high abrasion and absorption valuesin hot asphalt mixes. The use of four types of LQA having(41, 5.5) , (43, 6.1), (45,6.4) and (48, 7.5) abrasion and absorptionvalues respectively as coarse part in hot asphalt mixes wasinvestigated. These types of coarse aggregates were securedfrom Iura quarries. The fine portion of asphalt mixes understudy was natural sand and limestone mineral filler. Mix properties of the hot asphalt mixes containing the investigated LQA were determined and evaluated at various mixmgtemperatures . and asphalt types, using Marshall mixing technology. The improvement of mix properties by use of other mixing technologies was also investigated. The fieldperformance of the investigated mixtures was evaluated bystudying their resistance to water and load actions. Loss of stability and extraction tests were chosen to simulate the fieldconditions of the paving mixes.Analysis of results, indicated that the studied LQA can’t be used in hot asphalt mixes using the traditional mixing technology. These mixes not only require high quantity ofasphalt but also are highly sensetive to water and load actions.The results also indicated that untraditional mixing technologiesreduce the required optimum asphalt content (OAC), increase the stability values, and improve the resistance to water and load