In Situ Compaction Characterization of Dry Stacked Coal Combustion Residues

摘要

The Tennessee Valley Authority (TVA) has been conducting field trails and pilot projects since 2012 to evaluate new quality control/assurance methods for construction of dry stacked coal combustion residues (CCRs) at fossil plant facilities. Based on lessons learned from those studies, TVA is now implementing a method of material and plant specific field calibration procedure to establish process control and target values for quality control/assurance (QC/QA). This paper presents results of one such calibration effort performed at Cumberland Fossil Plant in Cumberland City, Tennessee. Field testing included using an instrumented vibratory smooth drum validated intelligent compaction (VIC) roller and in situ point test methods to measure moisture, dry density, modulus of subgrade reaction, shear wave velocity, and dynamic cone penetrometer resistance. Laboratory testing was conducted to assess compaction characteristics of fly ash and gypsum, and to assess influence of compaction delay and curing time on the chemically reactive fly ash material. Results from the field and laboratory testing are summarized in this paper along with the development of target values and field implementation practices.