Substantial upgrades to the current infrastructure in the United States are desperately needed. The American Society of Civil Engineers’ 2013 Report Card assigned a score of D to the United States’ roads for being “poor: at risk,” citing 32% of major highways in the United States in poor or mediocre condition (ASCE, 2017). As population increases so does vehicle traffic; this, combined with aging highways, has caused an increase in the demand of construction aggregates (FHWA, 2004).
Aggregates are made of crushed stone, gravel, and sand and are typically used as base materials for foundations and roadways and in concrete and asphalt mixes (Mamlouk and Zaniewski, 2011). Approximately 2 billion tons of aggregates are produced each year, domestically, and production is expected to increase to more than 2.5 billion tons by 2020 (FHWA, 2004). Aggregates distribute loads to underlying soil, reducing cracking in pavement, rutting, and deformation in the base/subbase layer (Tutumluer and Pan, 2008; Haider et al., 2014).
Coarse aggregates are mainly used in the construction of highway base/subbase layers to develop a pavement layer that can not only freely drain but also provide load distribution to the ...