Open sandwich slab

Pre-bonding. Fresh concrete is poured directly onto a layer of uncured adhesive spread over the prepared steel surface. This method, as used in the reinforcement of slab units by externally bonded plates, has been the subject of extensive research by the Wolfson Bridge Research Unit(lO). Open sandwich slabs, based on either a flat soffit plate or a plate curved slightly upwards to form a shallow arch have been recommended. The technique is described in some detail in Chapter 8. 

Dakers, J.J. The Design and Construction of Wester Duntanlich Bridge Deck using the Open Sandwich Slab Technique, MSc Thesis. University of Dundee, 1985. 

Fig. 8.2. Installation of open sandwich deck slabs on bridge south of Loch Tummel, Tayside.

Fig. 8.7. Conventional and open sandwich bridge deck slabs.

Foams consist of open or closed cell materials made from many plastics and may be used in sandwich panel manufacture from slab stock or by foaming in situ. The latter presents more problems of attaining uniformity of properties. Commonly used core materials include polyurethanes and rigid polyvinyls and polymethacryUmides (PMl) available in lightweight and industrial grades. 

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