h1

%0 Thesis
%A Nitsch, Andreas
%T Spannbetonfertigteile mit teilweiser Vorspannung aus hochfestem Beton
%V 13
%C Aachen
%I Publikationsserver der RWTH Aachen University
%M RWTH-CONV-118725
%@ 3-9807302-2-0
%B Schriftenreihe des IMB
%P Getr. Zählung : graph. Darst.
%D 2001
%Z Aachen, Techn. Hochsch., Diss., 2001
%X The behaviour of prestressed and precast members made of high strength concrete is strongly influenced by the increase in bond strength of the pretensioning tendons. In this paper the investigation results of the bond properties of prestressing steel in the transmission zone of prestress, in the area of cracks and in the anchorage zone are presented. In order to investigate the behaviour of prestressed and precast members made of HSC a series of pull-out tests, tests for the introduction of prestressing forces as well as tests on axially tensioned test-specimens and on different partially prestressed beams were carried out. The investigations resulted in considerably higher bonding forces in HSC containing silica fume, which are additionally influenced by lateral strains depending on the stress when tendons are released. This leads to a considerable reduction of the transmission length by transfer of prestress. Despite this, the required concrete coverage of tendons is no more than is necessary for normal strength concrete. The increase in bond strength results in an effective control of cracking by using smooth strands. In this way a design draft was developed in order to control crack width of partially prestressed members by strands only. The anchorage of pretensioned tendons at ultimate limit state is guaranteed, when the anchorage zone is free of cracks. Taking into account the influence of lateral strains in the anchorage zone with cracks, a bilinear bond strength characteristic of tendons should be used for design. The development of design codes for transfer of prestress, for control of cracking and for the anchorage zone of pretensioned tendons leads to a more cost-effective design for partially prestressed and precast high strength concrete girders.
%F PUB:(DE-HGF)11 ; PUB:(DE-HGF)3
%9 Dissertation / PhD ThesisBook
%U https://publications.rwth-aachen.de/record/56636