The determination of aggregate gradation is one important test that is performed during the design, production, and process control in the hot-mix asphalt and the aggregate industries. There is a need for an improved method of gradation analysis in which the gradation determination is accomplished in a more rapid, efficient, and accurate manner. After a review of current automatic gradation technologies, an automated gradation particle size analyzer was selected for further evaluation as a potential automatic gradation device. The automated gradation device performs gradation analysis through an automation of the standard gradation test procedures that are performed in laboratories throughout the country. Extensive evaluation of the device consisted, first, of determination of the optimum sieving time and sample size. Second, because the device is capable only of dry gradation analysis, an evaluation of the ability to use a correction factor to adjust the amount of dust or the percentage of material in the aggregate sample that passes the 0.075-mm sieve was also conducted. The results show that the automated gradation device, with the use of a correction factor, can accurately and precisely determine the gradation of an aggregate sample of approximately 1500 g in 10 min. The use of this device should result in an increased savings in technician and testing time as well as an economic benefit to the user.
Development and Potential Use of an Automated Aggregate Gradation Device
Transportation Research Record
Transportation Research Record: Journal of the Transportation Research Board ; 1673 , 1 ; 81-88
1999-01-01
Aufsatz (Zeitschrift)
Elektronische Ressource
Englisch
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