Field Performance Evaluation of Pavement Construction Platforms Utilizing Unconventional Large Size Aggregates Packed with Quarry Byproducts, and Higher Fines Aggregate Subgrade Layers

Quarry byproducts (QBs), usually less than 6 mm in size, are a major environmental and economic challenge for quarries as they accumulate in large quantities. Recent research at the Illinois Center for Transportation has evaluated new sustainable applications to utilize QB in pavement construction. Four full scale test sections were constructed to evaluate performances of pavement working platforms over a weak subgrade with an engineered strength of unsoaked California bearing ratio (CBR) of less than 1%. Two of the test sections utilized QBs packed into the voids of large-size aggregates, commonly referred to aggregate subgrade in Illinois and used as rockfill for building construction platforms over soft subgrade. To study the packing and percolation of the QBs through the large aggregates, and determine the optimum quantities of QBs to be mixed with the large-size aggregates, an extensive lab study was carried out to assess the packing of the two materials in a steel box. The large aggregates were added in one or two equal lifts, and the QB materials were evenly spread on the surface and then compacted with a laboratory-sized roller compactor. These applications were then replicated in full-scale test sections. The other two construction platform test sections studied the modification of soft subgrade by using aggregate subgrade materials with higher fines contents (up to 15% plastic and nonplastic fines, i.e. passing No. 200 sieve materials) than what is permitted in Illinois. This paper will present results of field rutting performance evaluations of these four construction platform test sections studied through accelerated pavement testing.