Code of Massachusetts Regulations › 780 CMR - STATE BOARD OF BUILDING REGULATIONS AND STANDARDS › Chapter 7 - Fire and Smoke Protection Features › Section 721 - CALCULATED FIRE RESISTANCE › Subsection 721.1 - General

Current through Register 1525, July 5, 2024
The provisions of this section contain procedures by which
				  the
fire resistance
of specific materials or combinations of
				  materials is established by calculations. These procedures apply only to the
				  information contained in this section and shall not be otherwise used. The
				  calculated
fire resistance
of concrete, concrete masonry and
				  clay masonry assemblies shall be permitted in accordance with ACI 216.1/TMS
				  0216. The calculated
fire resistance
of steel assemblies shall
				  be permitted in accordance with Chapter 5 of ASCE 29. The calculated
fire resistance
of exposed wood members and wood decking shall
				  be permitted in accordance with Chapter 16 of ANSI/AFPA
National Design
				  Specification for Wood Construction (NDS)
.
721.1.1
Definitions.
The
				following words and terms shall, for the purposes of this chapter and as used
				elsewhere in this code, have the meanings shown herein.
CERAMIC FIBER BLANKET.
A mineral wool insulation
				  material made of alumina-silica fibers and weighing 4 to 10 pounds per cubic
				  foot (pcf) (64 to 160 kg/m3).
CONCRETE, CARBONATE AGGREGATE.
Concrete made
				  with aggregates consisting mainly of calcium or magnesium carbonate, such as
				  limestone or dolomite, and containing 40 percent or less quartz, chert or
				  flint.
CONCRETE, CELLULAR.
A lightweight insulating
				  concrete made by mixing a preformed foam with portland cement slurry and having
				  a dry unit weight of approximately 30 pcf (480
				  kg/m3).
CONCRETE, LIGHTWEIGHT AGGREGATE.
Concrete made
				  with aggregates of expanded clay, shale, slag or slate or sintered fly ash or
				  any natural lightweight aggregate meeting ASTM C 330 and possessing equivalent
				  fire-resistance properties and weighing 85 to 115 pcf (1360 to 1840
				  kg/m3).
CONCRETE, PERLITE.
A lightweight insulating
				  concrete having a dry unit weight of approximately 30 pcf (480
				  kg/m3) made with perlite concrete aggregate. Perlite
				  aggregate is produced from a volcanic rock which, when heated, expands to form
				  a glass-like material of cellular structure.
CONCRETE, SAND-LIGHTWEIGHT.
Concrete made with a
				  combination of expanded clay, shale, slag, slate, sintered fly ash, or any
				  natural lightweight aggregate meeting ASTM C 330 and possessing equivalent
				  fire-resistance properties and natural sand. Its unit weight is generally
				  between 105 and 120 pcf (1680 and 1920
				  kg/m3).
CONCRETE, SILICEOUS AGGREGATE.
Concrete made
				  with normal-weight aggregates consisting mainly of silica or compounds other
				  than calcium or magnesium carbonate, which contains more than 40-percent
				  quartz, chert or flint.
CONCRETE, VERMICULITE.
A lightweight insulating
				  concrete made with vermiculite concrete aggregate which is laminated micaceous
				  material produced by expanding the ore at high temperatures. When added to a
				  portland cement slurry the resulting concrete has a dry unit weight of
				  approximately 30 pcf (480 kg/m3).
GLASS FIBERBOARD.
Fibrous glass roof insulation
				  consisting of inorganic glass fibers formed into rigid boards using a binder.
				  The board has a top surface faced with asphalt and kraft reinforced with glass
				  fiber.
MINERAL BOARD.
A rigid felted thermal insulation
				  board consisting of either felted mineral fiber or cellular beads of expanded
				  aggregate formed into flat rectangular units.