Influences of various construction and demolition materials on the behavior of a clay

Abstract

Construction and demolition (C&D) waste materials, which are environmental and financial problems, increase with continuous urbanization and industrialization. The C&D waste materials can be recycled and used as a material for new engineering applications. This study focuses on usage of the crushed brick, dragged asphalt, and crushed concrete paving slab aggregates with clay in pavement subbases. In this research, an intensive series of California Bearing Ratio (CBR), compaction, unconfined compressive strength (UCS), and swelling tests were carried out on the clay with various C&D waste materials. The performance of the implementation was investigated with the clay only, C&D materials only, and clay with C&D materials at the mix ratios of 5, 10, 15, 20 % by dry weight. The testing results showed a maximum of 13, 37, and 30 % increase in the CBR values of the mixtures with 20 % content of dragged asphalt, crushed brick, and crushed concrete paving slab of C&D waste materials, respectively. Compaction tests resulted in decrease in optimum moisture content (wopt) regardless of type of C&D materials, while maximum dry unit weight (γdrymax) changed based on the materials type. Performed UCS tests revealed that there has been an increase in strength of the mixtures as the amount of any C&D waste material increased in the mixture. Also, swelling percentage of the clay was found to decrease with an increase in the amount of any C&D waste material.