Published Resources Details
Journal Article
- Title
- Bond strength of reinforcing bars embedded horizontally in concrete
- In
- Journal of the Institution of Engineers, Australia
- Imprint
- vol. 14, no. 9, Sep 1942, pp. 201-217
- Description
This paper, No. 793, originated in the Adelaide Division of The Institution, and was presented before a General Meeting of the Division on 19th September, 1941. Since then, Professor Robin has carried out further experiments, the results of which are now included in the paper as published herein. Professor Robin, ME AMIEAust, is Professor of Engineering, University of Adelaide. Mr. Olsen StudIEAust, an officer of the Commonwealth Railway Department, was formerly C.S.I.R. Research Scholar in the Engineering Department of the same University. Mr. Kinnane is the present Research Scholar.
- Abstract
This investigation was undertaken to find what factors influence bond when reinforcing bars are cast into concrete in a horizontal position. The most important factor was found to be the amount of settlement which takes place in the concrete immediately after pouring. Some of the factors influencing the amount of such settlement have been found to be the water/cement ratio of the mix, the workability of the concrete, the size of concrete specimens, the degree of consolidation during casting, and the depth of wet concrete below the bar. In beams or in pull-out specimens, bars restrained from taking part in such settlement by a bridging action, allow small gaps to form under them and exhibit bond strengths in many cases dangerously weak.
Anchorage values of hooked and of deformed reinforcing bars have been tested and have been found in favourable cases to be sufficient to develop the yield strength of the bars. In many instances, however, this result is obtained only after a large slip. Hooked plain bars cast in the horizontal position in unfavourable conditions (i.e., in very thin blocks) exhibited no greater resistance to withdrawal than plain straight bars. Beams with hooked bars held against settlement and cast at the top were found to give much larger deflections than similar beams in which the bar was cast at the bottom.