Conclusions from this quarter's work are: There has been a gradual increase in the loss on ignition of samples of stockpiled AFB residue. The probable cause is carbonation due to the presence of free calcium oxide. Separating AFB residue into two fractions by use of a mineral cyclone did not produce a lime rich fraction. A stockpiled mixture of crushed stone and AFB residue became moderately cemented within three months. The presence of excess water appears to accelerate the cementitious reaction. Synthetic aggregate produced by briquetting exhibits aggregate properties which appear to be comparable to lightweight aggregate. Masonry units containing AFB residue can be successfully made under normal production conditions in a commercial block plant. Road base mixes containing less than 10% AFB residue develop satisfactory compressive strengths (up to 2100 psi in 28 days). The expansion of grout slurry mixes can be varied by adjusting the composition of the mix.