77
3220.036
Copeland, R.E.
Concrete Products
Article
Maclean Hunter Publications
1964
November
38-42
N
The Basic Building Code, issued by the Building Officials Conference of America, contains the following definitions:”Fire resistance. That property of materials or their assemblies which prevents or retards the passage of excessive heat, hot gases or flames under conditions of use.”
“Fire resistance rating. The time in hours or fractions thereof materials or their assemblies will resist fire exposure as determined by fire tests conducted in compliance with recognized standards.”
Obviously, concrete masonry is fire resistant but its degree of resistance remained a moot question until resolved by fire tests.
The first recorded standard fire tests of concrete block walls were performed at the Undersriters’ Laboratories, Chicago, in 1922. Since then approximately 100 standard size wall panels of concrete masonry and over 200 smaller panels have been fire tested at the National Bureau of Standards, Underwriters’ Laboratories and Portland Cement Association. Few, if any, construction materials have been more thoroughly researched as to fire resistance. While the information contains a few minor gaps it has proved reasonably adequate in meeting the needs of building officials, fire protection engineers, architects and the block industry.