Field tests on drilled shafts made with coal combustion by-products based concrete composites

Abstract Drilled shaft foundations are used commonly to resist compression, pull-out, and lateral loads from all kinds of structures ranging from single story buildings to multi-span heavy bridges. Recently, a field study involving testing of small diameter drilled shafts was completed to investigate the use of coal combustion by-products in the construction of drilled shaft foundations. The goals of this study were accomplished by conducting a series of laboratory tests to develop concrete composites containing pulverized coal combustion (PCC) by-products suitable for use in the construction of drilled shafts and field tests on drilled shafts. Based on the results of extensive laboratory investigation, two concrete composites and an equivalent conventional concrete were used to construct 330 mm diameter and 7.6 m long drilled shafts in the field and tested under field loading conditions. The drilled shafts were tested in compression using conventional top-down static load test and Osterberg Cell (O-Cell) tests, conventional axial pull-out tests, and lateral load tests. Results from the field tests on the drilled shafts are presented