A.S. DeVENNY and F.M. KHALAF Napier University, Edinburgh

The porosity of brick, its permeability and absorption are important factors in influencing such properties as the bond between it and mortar, the resistance to freezing and thawing and also its chemical stability and resistance to abrasion. The BS392I test for determining water absorption is the 5h boiling test which requires a large water bath and is not very accurate. This paper suggests a new test involving the boiling of 20mm brick lumps fur 5h which requires a smaller water bath and provides more accurate results. At present, tests and standards only exist for the determination of water absorption and moisture content in bricks. No tests exist to determine the porosity. A new test procedure for determining the porosity of bricks is described which involves the testing of small brick lumps under vacuum.