An Experimental Study on the Usability of Reclaimed Asphalt Pavements or Waste Bricks in the Stone Columns

This study presents experiments to find out if recycled asphalt pavements (RAP) or waste bricks (WB) can be used instead of natural aggregates (NA) in the stone columns that are used to increase bearing capacity and speed up consolidation settlement. The first step in this research was to get RAP, WB, and NA, then figure out a suitable gradation and unit weight for stone columns, and lastly do tests in the lab, such as pycnometer, minimum and maximum dry unit weights, water absorption, California bearing ratio (CBR), aggregate impact value (AIV), and large-scale direct shear tests. In order to perform CBR, AIV, and large-scale direct shear tests, it was necessary to find the unit volume weight in the stone column. Therefore, the model tests were conducted in a steel tank. The tank was filled with cohesive soil, so that soft soil conditions were created. And then, the stone columns with a diameter of 5 cm were built using RAP, WB, and NA in the middle of the soft soil. Thus, the unit weight values of RAP, WB, and NA were determined according to the amount of material used for the stone column. The results show that RAP and WB could be an alternative to NA for the stone column, although their strengths were lower than those of NA according to the shear strength parameters. However, it was thought that these waste aggregates should be used by improving their insufficient properties, such as water absorption and crushing behavior.