This paper presents methods of testing aggregate for use in arrester beds. Also presented are test results of five aggregates and the performance of the aggregates in the arrester beds. The test aggregates were obtained from five existing arrester beds throughout pennsylvania. They were pennsylvania state university (psu) river pea gravel, psu crushed aggregate, pleasant gap gravel, green tree gravel, and freeport gravel. Tests performed in the laboratory included gradation, specific gravity, los angeles abrasion, and freeze-thaw. In addition, particle angularity, sphericity, and shearing resistance were determined. The field performance of the test aggregates exceptgreen tree gravel was evaluated in terms of mean average truck deceleration in the bed. The available data show that psu crushed aggregate performs most poorly of the four. The other three perform nearlyequally well, although pleasant gap gravel has a static internal friction angle considerably lower than psu river pea gravel. These results indicate that aggregate performance depends not only on interparticle friction but also on other properties such as particle angularity and sphericity. For long-term performance, particle durability is also an important factor. Thus, testing of aggregate for use in the arrester bed should involve determination of gradation, interparticle friction, angularity, sphericity, and durability. This paper appears in transportation research record no. 1250, Innovation in aggregate testing.
Abstract