Experimental study on the bearing capacity of concrete blocks loaded through square and circular steel plates

Abstract

The bearing capacity of concrete loaded through steel plate has been the subject of numerous studies, play as an important element that need to be considered in designing many types of concrete members such as foundation structure, the end bearing zone of prestressed post-tensioned concrete beams and even for concrete pedestal in bridges. This paper presents an experimental investigation into the bearing capacity of concrete blocks axially loaded through square and circular steel plates. The relative area of the surface of concrete block specimen to the area of the bearing plate is one of the most significant factors influencing the bearing capacity of concrete blocks. Thus, the main purpose of this study is to determine the maximum bearing capacity and observe the failure modes of concrete blocks concentrically loaded through square and circular steel plates. A total of twenty-one (21) numbers of specimens with three different types of concrete blocks were experimentally investigated. There are three (3) specimens of plain concrete blocks, nine (9) specimens of concrete blocks laterally reinforced with ties (loaded and tested under three different sizes of square steel plate) and nine (9) specimens of concrete blocks laterally reinforced with ties (loaded and tested under three different sizes of circular steel plate). The use of steel plate helps in determining the bearing capacity when concentrically loaded on top of the specimen. The results of the experimental testing herein were compared with the bearing capacity values calculated based on previous researches and international standards. Experimental results demonstrate that concrete blocks laterally reinforced with ties loaded and tested under larger relative area of the steel plate gave lower value of bearing capacity compared with other reinforced specimens. Meanwhile, the failure pattern of concrete blocks under the bearing load was found to vary with the increase in sizes of steel plates.