C. J. Burgoyne
Lecturer, Engineering Department, Cambridge University,
Cambridge, UK
T. J. Ibell
Research Student, Engineering Department, Cambridge University,
Cambridge, UK
This paper briefly reports on a
series of experiments carried out on strip-loaded prestressed concrete end
blocks. The results show that corresponding design methods presently used in Europe are conservative. In all cases, failure of the end
blocks was by initial cracking, followed by wedging punch-through of the plate.
When a large prestressing force is
applied to the end of a beam over a small anchorage area, tensile bursting
stresses are developed behind the anchor plate. The problem of analyzing the
bursting stresses in concrete blocks under concentrated loading has been
investigated in the past by several researches [Clarke, 1976; Guyon, 1974;
Leonhardt, 1964; Morsch, 1924; VSL, 1975; Zielinski and Rowe, 1960]. Such work
has led to commonly accepted empirical design methods for the detailing of
steel reinforcement in end blocks.
The present experimental series was
carried out in order to study the effect of steel quantity and positioning on
the load carrying capacity of strip-loaded end blocks. The results from this
test series are presently being used to verify upper- and lower- bound theories
for the analysis of end blocks.
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