Recipient: School of Civil and Environmental Engineering
Oklahoma State University
Grant: $155,681
Completion: 2023
Project Summary: 31
Background and Need
Quality control and quality assurance (QC/QA) of unbound aggregate layer construction in pavements has traditionally been based on measuring density using a nuclear density gauge. Measuring density of open-graded bases (OGA) for permeable pavements, however, is next to impossible, as results are highly variable. This research addressed the need for developing compaction specifications based on deflection criteria measured with a Light Weight Deflectometer (LWD), a technology in existence since the 1980s. This cutting-edge work follows recent development of LWD protocols and an AASHTO provisional specification for deflection measurements on compacted subgrade soils and dense-graded bases. Several state departments of transportation (DOTs) in the US (e.g. Florida, Indiana, Nebraska and Minnesota) have adopted compaction control specifications for these materials using LWDs. The trend toward using LWDs among other state DOTs is growing due to the inexpensive, reliable, and fast nature of the tests.