Aggregate Subgrade Improvements Using Quarry By-Products: A Field Investigation

US Transportation Collectionhttps://doi.org/10.36501/0197-9191/21-0172021PDFTech ReportQamhia, Issam I. A.Tutumluer, ErolWang, HanIllinois Center for TransportationUniversity of Illinois at Urbana-Champaign. Department of Civil and Environmental EngineeringIllinois. Dept. of Transportation. Bureau of ResearchUnited States. Department of Transportation. Federal Highway AdministrationIllinois Center for TransportationIllinoisUnited StatesAggregatesField studiesImprovementsPavement maintenanceQuarriesSubgrade (Pavements)Traffic loadsWaste products (Materials)Case studiesNondestructive testsAggregate Subgrade ImprovementQuarry By-product AggregatesField EvaluationSustainable ConstructionBack-calculationAggregate BlendsFHWA-ICT-21-012R27-SP43Final Report 5/16/20\u20136/30/21This report presents a case study for constructing aggregate subgrade improvement (ASI) layers using quarry by-product aggregates (QBA), a quarry mix of large primary crushed rocks (PCR) and sand-sized quarry fines. The construction took place at Larry Power Road in Bourbonnais Township in Kankakee County, Illinois, where the Illinois Department of Transportation placed two QBA mixes. The first mix (QBA_M1) consisted of 45% quarry by-products and 55% railroad ballast\u2013sized 3 71 PCR. The second mix (QBA_M2) consisted of 31% and 69% quarry by-products and PCR, respectively. Two conventional ASI sections were also constructed conforming to Illinois Department of Transportation\u2019s CS02 gradation. All sections consisted of a 9 in. (229 mm) QBA/PCR layer topped with a 3 in. (76 mm) dense-graded capping layer. Laboratory studies preceded the construction to recommend optimum quarry by-product content in the QBA materials and construction practice. The Illinois Center for Transportation research team monitored the quality and uniformity of the construction using nondestructive testing techniques such as dynamic cone penetrometer, lightweight deflectometer, and falling weight deflectometer. The segregation potential was monitored by visual inspection and imaging-based techniques. Short-term field evaluation of the constructed QBA layers, particularly QBA_M2 with a 31% quarry by-product content, showed no evidence of abnormal segregation and did not jeopardize the structural integrity of the QBA ASI layers, which had slightly lower but comparable strength and stiffness profiles to the conventional ASI sections. The use of QBA materials in ASI was field validated as a sustainable construction practice to provide stable pavement foundation layers.120