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8-in. Bearing Wall of Concrete Masonry Units Made With Expanded Shale (Rotary Kiln Process) Aggregate

• ID:

  58

• ESCSI:

  3220.017

• Author:

  Zimmer, B.A.

• Publication Name:

  R3746-9, 69CH2774

• Type of Publication:

  Paper

• Publisher:

  Underwriters' Laboratories, Inc. and ESCSI

• Dated:

  1969

• Issue/Volume:

  November 3

• Other ID:

• Page(s):

  1-8 + illus.

• Reference List:

  N

• Abstract:

  This report describes the results of a fire endurance test conducted on an 8 in. concrete masonry load bearing wall on September 26, 1969 at our Chicago Laboratories.The purpose of the investigation was to determine the minimum equivalent thickness for Class B-4 concrete masonry units made of expanded shale, clay, or slate aggregate, produced by the rotary kiln process, and of a 1 to 10 batch mix proportion based upon the fire performance of the unit described in this report.
  The end point of the fire endurance test occurred at 223 min. for the 5 in. ET (actual 5.02 in.) units.
  The wall reached the end point of the test when the limiting maximum average temperature of 325 F was reached at 223 min. (3 hr, 43 min).
  Since the 5 in. ET units did not meet the conditions of acceptance for a 4 hr. fire resistance rating, we are not in a position to establish the equivalent thickness requirements for Class B-4 concrete masonry units.
  Accordingly, this letter concludes our work under File R3746, Assignment 69CH2774 and we are advising our accounting department to close the assignment.