Bearing Strength of Circular Concrete Blocks Varies in Heights Subjected to Concentrically Circular Loaded Bearing Plate

Abstract

Bearing strength is vital when transferring the heavy loaded over limited area of concrete surface. This paper examines the bearing strength of circular concrete blocks with different heights loaded under circular bearing plate. Bearing strength of concrete are strongly related to the compressive strength of concrete and the ratio of total area of concrete surface to loaded steel bearing area. This study focuses on the confinement effects of concrete for different heights of concrete blocks. Most existing design codes propose specific criteria to prevent bearing failure but not included size effect such as height of concrete block. Height of concrete block is one of important criteria in designing concrete bearing especially for shallow or slender structural supports. For the present study, there are total of 18 concrete blocks has been tested under compression and bearing tests, i.e. 9 blocks for compression test (150 mm3) and 9 blocks for bearing test in three different heights, i.e. 50 mm, 100 mm and 200 mm with constant concrete diameter of 100 mm. The confinement effect of concrete is analysed based on two dimensionless units, i.e. (fb/fc) and (h/d) ratios. The failure modes for different height of concrete blocks observed. The effect of different heights on concrete bearing also explained.