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Determination of Equivalent Thickness of Concrete Masonry Units

• ID:

  66

• ESCSI:

  3220.025

• Author:

  Allen, L.W. and T.Z. Harmathy

• Publication Name:

  Determination of Equivalent Thickness of Concrete Masonry Units

• Type of Publication:

  Article

• Publisher:

  Div. of Bldg Research, natl Res. Council, Canada

• Dated:

  1971

• Issue/Volume:

  March

• Other ID:

• Page(s):

  1-5

• Reference List:

  Y

• Abstract:

  The fire endurance of concrete masonry walls depends primarily on the aggregate used and the amount of solid per unit area of the wall. In the National Building Code of Canada, concretes are classified as types S, N, or L, according to the fire endurance characteristics of the aggregate.The assumption that fire endurance is directly related to the amount of solid material present in the units is sufficiently accurate for most practical applications. It is understandable, therefore, that the concept of using “equivalent thickness” to correlate the results of fire tests has been widely adopted.
  The equivalent thickness of a hollow masonry unit is usually defined as the product of the over-all thickness of a unit and the ratio of its net volume to its gross volume. The over-all thickness and gross volume can be determined from simple measurements. Determining the net volume, however, may often present some difficulties.