Utilization of Building Debris as Aggregates in Stone Columns

Project Engineer B.Sc. Eng. Hons (Moratuwa), M.Eng. (Moratuwa), AMIE (Sri Lanka) Department of Civil Engineering B.Sc. Eng. Hons (Moratuwa), M.Eng. (AIT), Dr. Eng. (YNU), C.Eng., FIE (Sri Lanka) Due to rapid development and population growth, construction industry has emerged with few recent problems. The major problem faced by the construction industry is the scarcity of construction materials associated with environmental concerns on consuming virgin materials such as rock and soil. In addition to this, disposal of construction waste because of high disposal cost and inadequate land fill area has become a grave concern. Due to the remnants of 30- year civil war happened in Sri Lanka, a huge amount of building debris is to be disposed during new infrastructure construction on the war affected areas mostly on soft and compressible soils. To reduce the amount of dumping these building debris, the possibility of using them (concrete, brick and plaster) in lieu of traditional rock aggregates as material to be used in stone column construction was studied in this research. Slake durability index and uniaxial compressive strength tests were carried out on selected building debris to find out the suitability of using them in stone columns. Improvement in shear strength of the soft soil was tested using Vane shear in radially as well as with depth in several laboratory models with a centrally located stone column made up of different building debris. It was observed that the model with concrete aggregates exhibited a similar capacity of traditional rock aggregates of same size