This investigation was undertaken to determine the feasibility of producing a cellular, lightweight product by subjecting shales to temperatures of 2100 ± 100 °F in a muffle furnace. Such a product can be utilized as an aggregate for lightweight concrete to supplement cinders which have long been used. The growing scarcity of cinders and the inferior quality of the cinders now available account for the demand for another material to replace them. Samples of weathered and non-weathered, Liberty Hall shale; non-weathered, Martinsburg shale; weathered and non-weathered, MacCrady shale; and non-weathered, Brillier shale were obtained from deposits located in the state of Virginia. The degree of bloating or expansion of the shales was measured by determining the bulk density of the shale before and after exposure to 2100 ± 100 °F. The best bloating shale investigated, non-weathered Liberty Hall, bloated from a bulk density of 2.349 to 0.544 gram. per cubic centimeter; while the poorest bloating shale, Brallier, bloated from 2.448 to 2.389 grams per cubic centimeter. In a firing test on tour types of whale, weathered and non-weathered Liberty Hall and non-weathered Martinsburg and Brallier, it was determined that only 12.5 percent of the total bloating occurred in the temperature range between 70 and 1900 °F, while 87.5 percent occurred in the temperature range from 1900 to 2200 °F. In firing tests using non-weathered Liberty Hall shale it vu found that no additional bloating occurred after prolonged heating at 2050 °F for forty-five minutes. This was indicated by no change in the bulk densities of the fired and unfired test specimens. Additional firing tests using specimens of non-weathered Liberty Hall. shale indicated that a rapid firing schedule was conductive to good bloating. The specimens showed bulk densities of 0.524 and 0.623 gram per cubic centimeter when heated to 2050 °F in twenty minutes and one hour and forty-five minutes, respectively. Weathered and non-weathered MacCrady shale showed no bloating tendencies at the temperatures used. in this investigation. The densities of cinder concrete and bloating shale concrete were 93.47 and 114.3 pounds per cubic foot, respectively. The densities of these materials compare favorably with ordinary sand and gravel concrete which weighs approximately 145 pounds per cubic foot. / Master of Science

Shale barrens are unique habitats located throughout the southern Appalachians. They are characterized by a south or south west aspect, a steep slope, and an exposed rocky surface (Platt, 1951). They have a high total irradiance and can experience temperatures higher than the surrounding deciduous forest. A variety of plant species, several of which are rare or endangered, are endemic to the shale barren habitat. One reason proposed fc)r their endemism is that the plants are obligate heliophytes (Keener, 1983). The purpose of this dissertation is tel examine the acclimation ability of the shale barren endemic Eriogonum alIeni to shade and high temperature. / Ph. D.