The investigations reported in this thesis were made to obtain information regarding three materials that were thought to be possible sources of aggregates for light-weight concrete--expanded clay shale from Rock River, Wyoming; spent oil shale from Rifle, Colorado; and scoria from the vicinity of Gillette, Wyoming. Although the results obtained from these investigations do not indicate all of the specific properties of the aggregates and of the concrete made with these materials as aggregates, they may serve to point out promising fields for further investigations, and they may serve as a guide for further experiments.