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Report on Bearing Walls of Concrete Masonry Units (Blocks) Made with Rotary Kiln Process, Coated and Uncoated, Expanded Shale, Clay and Slate Aggregates

• ID:

  95

• ESCSI:

  3220.054

• Author:

  Fandel, J.A.

• Publication Name:

  File R3746, Assignment 65C 3172F

• Type of Publication:

  Paper

• Publisher:

  Underwriters' Laboratories, Inc. and ESCSI

• Dated:

  1965

• Issue/Volume:

  August 4

• Other ID:

• Page(s):

  G1, 1, 2

• Reference List:

  N

• Abstract:

  Wall No. 3 was assembled of blocks having 1-3/4 in. face shells and an equivalent thickness of 4.97 in (Block Design 3). The blocks in one-half of the wall were of an uncoated aggregate (Block B-3); the other half of coated aggregate (Block D-3).Review of the fire test conducted on Wall No. 3, illustrated in the summary of full scale tests, shows an end point of 181 min for blocks produced with the uncoated aggregate and 180 min for the coated aggregate. On the basis of this test, it is judged that no significant difference exists in the fire resistance characteristics of coated shale or uncoated clay, (rotary kiln processed) aggregate when used in bearing walls of concrete masonry units.
  It is judged that bearing walls of concrete masonry units (blocks) made with rotary kiln process, coated and uncoated, expanded shale, clay and slate aggregate, will afford 2, 3, and 4 hr. protection when produced in accordance with the specifications outlined in the Standard for Concrete Masonry Units, UL 618.
  Appropriate revisions to UL 618 to include the above change in aggregate description will be processed in the normal manner for such Standard revisions.