The Fundamental Geotechnical Characteristics of Recycled Concrete Aggregates of Various Fractions

The purpose of this study is to determine the fundamental characteristics of a recycled concrete aggregate for its utilization in geotechnical constructions. Minimum and maximum bulk densities, the shear strength properties, and the deformation properties were tested in the laboratory. The tests were performed on recycled concrete aggregates of basic fraction, i.e., 0-16 mm, and separated fractions, i.e., 0-4 mm, 4-8 mm, and 8-16 mm. The laboratory tests on the recycled concrete aggregate were compared with the results of the natural aggregates sorted into comparing fractions with the recycled concrete aggregate. The bulk density of the recycled concrete aggregate was either less or equal to that of the natural aggregate. The shear strength properties of the recycled concrete aggregates were greater than the shear strength properties of the natural aggregates except for the fraction of 8-16 mm, where it was the opposite. The one-dimensional compression modulus of the recycled concrete aggregate is slightly lower than that of natural aggregate for the fractions of 4-8 mm, 8-16 mm, and 0-16 mm. However, for the fraction of 0-4 mm, which is not typically used in the creation of recycled concrete (because it is replaced by the natural aggregate), the recycled concrete aggregate has a higher shear strength and compression modulus than natural aggregate.