This paper presents the results of compaction quality control (QC) tests performed in the context of construction of a class-F fly ash and bottom ash mixture embankment on SR 641, Terre Haute, IN. Prior to embankment construction, a test pad was constructed at the site to allow establishment ofQC criteria based on Dynamic Cone Penetrometer (DCP) and Lightweight Deflectometer (LWD) test results. The preliminary DCP and LWD data were correlated with the in situ dry unit weight and the moisture content of the compacted ash. The effects of lift thickness and number of roller passes on the measured DCP blow count (DN) and LWD modulus (ELWD) were assessed and taken into consideration in the development of the QC criteria. Based on theresults of the DCP and LWD tests performed on the ash mixture test pad and the requirement that the in place dry unit weight of the fill material be over 95% of the laboratory maximum dry unit weight, DN=7 for 0-to-150mm penetration or DN=14 for 0-to-300mm penetration and ELWD=22MN/m2 were recommended for compaction QC of the ash mixture embankment constructed in lifts of 150mm and compacted with three roller passes. Resilient modulus (MR)values of the ash mixture samples prepared at the optimum moisture content ranged from 33.7MPa to 45.8MPa. Findings from this research can advance the use of compaction QC methods in the construction of ash embankments and also facilitate the design of pavements constructed over ash subgrades.
Abstract