Development of expandability charts for Ankara Kalecik Clay: Fid-Bau Portal

Development of expandability charts for Ankara Kalecik Clay

Ozguven, Ahmet

Abstract The main aim of this study is to establish optimum working conditions and to propose expandability charts for Kalecik Clay using expansion ratio versus unit volume weight values via a statistical computer program (Design Expert 7.0). First of all, some suitable samples were collected from the Kalecik County (Ankara, Turkey). Later, the samples were crushed and milled up to 200μm clay size in the laboratory. Then, pellets with a 10mm diameter were dried in ovens and heated inside a furnace to expand in different temperatures. One heating operation began with 900°C and ended with 1200°C. In addition to that, the holding time periods were selected as 5, 10, 15 or 20min for each operation. In the final stage, the unit volume weight and expansion ratio of the produced aggregates were determined. As results of this study, both the optimum furnace holding time and furnace temperature values for the samples were determined in order to maximize the expansion ratio values and minimize the unit volume weight for Kalecik Clays. Some expandability charts were proposed for Kalecik Clay by using the findings. The charts allow one to assign expansion ratio and unit volume weight values in different working conditions including holding time inside the furnace and furnace temperature. The proposed charts are expected to be quite useful for more efficient production of expanded clay aggregates in construction industry.

Highlights • Optimum working conditions for expanding Kalecik Clay were determined. • Expandability charts including expansion ratio and unit volume weight were developed. • Values obtained from expandability charts reflect the real conditions well. • Charts could be of help to construction industry for producing clay aggregates.