1 Babtie Group Ltd, Blackfirars London, England
13 Manchester Centre for Civil & Construction Engineering, UMIST, Manchester, England

The compressive strength of concrete block masonry is dependent upon the unit compressive strength, the type of unit, the mortar and the form of masonry construction. The design codes allow masonry compressive strength to be determined by calculation, from tests, or from tabulated values based on block strength and mortar type but do not adequately allow for the unit type or for the form of construction. Although the current British masonry standard BS5628: Pt.l [1] tabulates some masonry strengths, increased use of alternative forms of masonry construction to avoid the use of heavy units have required that the tables be extended. To provide the data for an extension to the tables in BS5628: Pt.l [1J and at the same time to provide input to the development of Eurocode 6 [2], a major research programme was set up in 1995. The research programme was to test waliettes constructed with, void units, with collar joints and different tying arrangements and with solid units laid flat. This paper describes the tests carried out on wallettes constructed with solid blocks laid in collar jointed construction.