Experimental road base construction utilizing atmospheric fluidized bed combustion residue. Research report (Final)

This report summarizes findings of laboratory and field trial evaluations of two experimental test sections constructed adjacent to one another. One experimental section contained a mixture of pulverized fuel ash, residue from an atmospheric fluidized bed combustion process, and limestone aggregate. The second section contained a similar mixture but included a small amount of Type III cement. Both experimental sections were constructed to a total nominal thickness of nine inches. The typical design section included six inches of the experimental mixtures, used as base materials, beneath three inches asphaltic concrete. A previous report documented construction of the test sections and preliminary performance evaluations of the experimental base mixtures. Analyses of additional periodic deflection testing are detailed within this report. The experimental sections were monitored over a three-year period. It was concluded, based upon performance observations and evaluation activities, that both experimental mixtures are suitable for use as a road base material. Both test sections performed well with no cracking, rutting or unexpected deterioration observed. Results of the deflection testing activities indicated that the pavement structure containing cement had somewhat higher stiffness values and generally maintained those values over time.