Wear Resistance and Hardness Assessment of Five US Hardwoods for Bridge Decking and Truck Flooring*

Abstract

The wear resistance and Janka hardness of five United States hardwood species were evaluated for potential use in bridge decking and truck flooring. The species tested include ash (Fraxinus sp.), hickory (Carya sp.), red oak (Quercus sp.), sweetgum (Liquidambar styraciflua), and white oak (Quercus sp.). The specimens were prepared with the sizes of 1 by 2 by 4 inches (2.54 by 5.08 by 10.16cm) for abrasion test and 1 by 2 by 6 inches (2.54 by 5.08 by 15.24 cm) for Janka hardness testing. The specimens were cut from 30 individual parent boards of random width with clear sections for each species. The abrasion and Janka hardness tests were performed according to the American Society of Testing and Materials standards. All wear and hardness data were statistically analyzed by 1-way analysis of variance. The results of this study demonstrated that sweetgum with the lowest density had the greatest amount of thicknesses loss and thus lowest wear resistance. White oak was found to have the least thicknesses loss, thus highest wear resistance among the hardwood species tested. Hickory, with the highest density, had the highest hardness among the hardwood species tested, but it had relatively lower wear resistance comparing to ash, red oak, and white oak.

Estimating a Regional Economic Conservation Benefit of Using Domestic Hardwoods vs. Apitong for Trailer Decking: A Case Study on US Army Use

“…Even high-grade lumber from species such as oak, hickory, or black locust are not perfect substitutes for apitong. Rather, these domestic hardwood species could sufficiently meet (not necessarily exceed) specifications [8].…”

“…In the US, the species is considered to be one of the most popular exotic hardwood species, and has been the "undisputed" choice for truck and trailer flooring (decking) since the 1960s [7]. The US Army is one of the biggest users of apitong, currently utilizing wood panels derived from it as decking for many of their vehicles and trailers [8,9]. A primary supplier of military trailer flooring, reports suggest that the majority of rough kiln-dried apitong lumber comes from tropical rainforests in Malaysia and Indonesia [10].…”

“…Apitong is considered a preferred species for trailer decking due to its superior characteristics, including hardness, rupture and crushing strength, elasticity, and availability in long, clear lengths [8,20,21]. Furthermore, the wooden decks must withstand extreme wear and tear associated with US military use, as well as exposure to sunlight, heat, rain, fungi, and insects.…”

“…It has been recognized that the use of tropical species is in contrast with US Army specifications, and alternatives have been sought since as early as 2000 [20], yet apitong is still used as decking for the US Army's trailers. In recent studies, Khademibami et al [21] and Khademibami et al [8] identified the issue and studied the mechanical properties of domestic species, including hickory, red oak, and white oak, which could be suitable alternatives to apitong for trailer decking. To date, however, no study has evaluated the economic impacts of replacing apitong panels with domestic species.…”

“…Khademibami et al [8] examined ash (Fraxinus spp. ), hickory, red oak, sweetgum (Liquidambar styraciflua), and white oak for abrasion and hardness as potentially sustainable alternatives to apitong and for general use in high-wear environments such as trailer decking.…”