Abstract
Synthetic aggregates produced by firing clays and shales are being increasingly used in the construction of concrete and asphalt structures. The anomalistic behavior of this synthetic product requires an extensive study of the material. This research was a study of the changes in both mineralogical and physical properties of clays and shales during the process of firing. An attempt was made to explain a portion of the mechanical behavior of synthetic aggregates in relation to their fundamental properties. The laboratory investigation was divided into two phases. During the first phase of this work, eight samples were selected to study the effects of temperature, rate and time of firing on bulk specific gravity and absorption characteristic of the fired materials. Two firing rates, designated as slow and rapid firing, were used for five samples. All eight samples were subjected to rapid firing for 8 and 15 minutes. A Globar furnace was used to fire the samples to temperatures ranging from 1200 to 2400°F. Mineralogical changes in all samples fired under rapid firing for 15 minutes were studied using X-ray diffractions, differential thermal analyses, and petrographic examinations. The second phase of this investigation was a study of the effects of firing temperature on microstructure, resistance to rapid freeze-thaw and abrasion, alkali-silicate reaction, compressive strength, and modulus of elasticity of the fired products. Two samples were studied in this phase of work. Several conclusions that were drawn from the test results follow: &
Das, Subodh Kumar (1967). Studies of fundamental properties and mechanical behavior of selected synthetic aggregates. Doctoral dissertation, Texas A&M University. Texas A&M University. Libraries. Available electronically from
https : / /hdl .handle .net /1969 .1 /DISSERTATIONS -179188.