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原文传递 Evaluation of Non-Destructive Density Determination for QA/QC Acceptance Testing.

题名：	Evaluation of Non-Destructive Density Determination for QA/QC Acceptance Testing.
作者：	Mata, D.; Ferguson, N.; Cooper, S. B.; Gautreau, G.
关键词：	Density determination, Long-term pavement performance
摘要：	Density is often considered one of the most important parameters for long-term pavement performance. Proper density specifications require the contractor and the Louisiana Department of Transportation and Development (DOTD) to follow quality control (QC) and quality assurance (QA) procedures. Contractors often utilize the nuclear density gauge (NDG) as part of their QC processes to monitor density (and soil moisture) for earthwork and unbound layers; and to establish rolling patterns for asphalt pavement layers. DOTD QA procedures require determination of density utilizing NDG for earthwork and unbound layers; and roadway core densities for asphalt pavement layers. However, nuclear technology in the NDGs requires extensive certifications and handling procedures; and the coring process is a destructive testing process to a freshly paved asphalt mat. This research investigated the potential of low to non-nuclear devices with little to no radioactive footprint, to replace the NDG and roadway coring for asphalt and soils QA operations in Louisiana. The newly developed gauges are simple and easy to use and do not require extensive training, certifications, or lengthy paperwork; and are less destructive to the road. For this research, two separate field and lab evaluations took place: (1) LTRC鈥檚 Geotechnical group evaluated the final density procedures for soils and (2) LTRC鈥檚 Asphalt group evaluated the final density procedures for asphalt pavements. The study determined the NDG to be a better option for DOTD in soils QA processes; and the non-destructive testing (NDT) for asphalt, a.k.a. thin-lift nuclear density gauge (TLNDG) and non-nuclear density gauge (NNDG), to be viable options for asphalt QA processes. The low-nuclear density gauge (LNDG) exhibited limitations of depth requirements and service life. The TLNDG and NNDGs were shown to have good correlation to core density results. NDT was determined to be safer, faster, better for the longevity of the pavement, and more economical for both contractors and DOTD.
报告类型：	科技报告