Reinforced masonry steel splices by Electronic Blueprint
Electronic Blueprint and ENVIROSPEC provide building specifications
and training, on safe and sustainable buildings, for architects, engineers and
builders. The use of high strength steel reinforcement requires relatively long
lap lengths to effectively splice tensile reinforcement. Two papers at the 14th
International Brick & Block Masonry dealt with this issue:
Mjelde, J.Z., Mclean, D.I., Thompson, J.J., Mcginley, W.M., "Performance of lap
splices in concrete masonry shear wall under in-plane loading," 14th International
Brick & Block Masonry Conference, Sydney, Australia, 2008. And Thompson, J.J.,
Lang, N., "Effects of confinement reinforcement on the performance of lap splices
in concrete masonry," 14th International Brick & Block Masonry Conference,
Sydney, Australia, 2008.
The first paper described a series of tests on reinforced concrete masonry in
flexure and shear. It concluded that laps lengths of 48 bar diameters give
satisfactory performance, provided the reinforcement is placed in the centres
of the hollow concrete block cells, and is accompanied by horizontal reinforcement.
Where reinforcement is offset in the cells, the reduced cover leads to reduced
transfer of stress, with resulting drop in performance.
The second paper described the beneficial effect of introducing transverse
confining reinforcement into reinforced masonry walls to reduce this lap length.
It reports benefits up to a particular limit, beyond which there is little further
increase. The paper gives an equation, which may be incorporated into design
standards to enable reduced lap lengths, provided the design area of transverse
reinforcement is limited to 225mm², and the lap length is not reduced below
914 mm.
For further information, please contact the publishers, University of Newcastle,
Callaghan, NSW, 2308, Australia or Electronic Blueprint www.electronicblueprint.com.au.
For further information contact:
Electronic Blueprint
phone: +61 2 4360 2255
fax: +61 2 4360 2256
web: www.electronicblueprint.com.au
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