ACI Code Requirements for Determining Fire Resistance of Concrete and Masonry Construction Assemblies. for Determining. Fire Resistance of. Concrete and Masonry. Construction Assemblies. Reported by ACI/TMS Committee A. CI/TMS M An ACI /TMS. Find the most up-to-date version of ACI at Engineering
It is based on extensive research which established a relationship between physical properties of materials and the fire resistance rating.
The fire resistance rating is based on the equivalent thickness of the concrete masonry unit and the type of aggregate s used in its production. More importantly, the Standard is a document that has gone through a formal consensus process and is written in mandatory language, and therefore is now incorporated by reference into the national model codes. Norlite, LLC S. The listing service also monitors materials and production to verify that the concrete masonry units are and remain in compliance with appropriate standards.
For partially grouted concrete masonry walls using 8-inch thick cmu rated at 2 hours, the fire-resistance rating can be increased to 4 hours when ungrouted cores are filled with any of the following: Concrete masonry is widely specified for fire walls and fire separation walls because these elements are:. The fire resistance rating of steel columns protected by concrete masonry as illustrated in Figure 4 is determined by the following equation:.
Fire Resistive Ratings
The model building codes recognize that the fire resistance rating of 2116.1 concrete masonry unit cmu is based on it’s equivalent thickness and type of aggregate, using linear interpolation if aggregates are blended in the cmu. Site Map Take me to the homeowner’s site. The times listed in Table 8 are essentially the length of time the various finishes will remain intact when exposed to fire on the fire side of the wall.
The system also is somewhat inflexible in that little variation from the original tested wall assembly is allowed including unit size, shape, mix design, ingredients, and even the plant of manufacture. This is accomplished by insuring that the temperature rise of the tensile reinforcing does not exceed o F o C during the rating period.
To calculate the fire resistance rating of a concrete masonry unit, its equivalent thickness and the proportion of aggregate s used in its production must be known. Lath nails ack at 12 in. Table 7 applies to finishes on the non-fire exposed side of the wall and Table 8 applies to finishes on the fire exposed side. This type of failure mode is certainly preferable to a structural collapse endpoint characteristic of many other building materials from the standpoint of life safety particularly for fire fighters and salvageability.
Typical equivalent thickness values for these units are listed in Table 2. For the lightweight units 93 and pcf density the net volumes in Table 3 were reduced approximately 2. This TEK covers methods for determining the fire resistance rating of concrete masonry assemblies, including walls, columns, lintels, beams, and concrete masonry acl protection for steel columns. In many cases drywall, plaster or stucco finishes are added to concrete masonry walls. For partially grouted concrete masonry walls using 8-inch thick cmu rated at 2 hours, the fire-resistance rating can be increased to 4 hours when ungrouted cores are filled with any of the following:.
The minimum required cover over the vertical reinforcement is 2 in. The document highlights code sections related to masonry and fire-resistance. Extensive testing has established a relationship between the fire resistance and the equivalent solid thickness for concrete masonry walls as shown in Table 1.
Self-tapping drywall screws spaced a maximum of 12 in. NCMA Tek Table 2 Calculation of the fire resistance rating for the pcf normal weight units in Table 1 was performed using the appropriate values from Table 2 and Table 3, using linear interpolation between the hourly ratings for each material. While finishes are normally applied for architectural reasons, acj also provide additional fire resistance value.
It is based on thousands of tests. These hourly fire resistance ratings can be established by three different methods:.
This is then added to the base concrete masonry wall equivalent thickness which is used in Table 1 to determine the fire resistance rating. Saratoga Street Cohoes, NY phone fax info norliteagg. A premium is usually charged for units of this type. This is to assure structural integrity during a fire.
It is a multi-functional system in a single package: When calculating the fire resistance rating of a wall with finishes, two calculations are performed. Gypsum wallboard and gypsum lath may be attached to wood or metal furring strips spaced a maximum of 24 in.
The fire-resistance rating of walls with cmu using blended aggregates is determined per CBC Section The fire resistive properties of concrete masonry units are generally classified by hourly fire resistance ratings.
Cover requirements may be provided by masonry units, grout, or mortar. Therefore, two separate tables are required. It is incorporated by reference into the major model codes of the US and allows the designer virtually unlimited flexibility to incorporate the excellent fire resistive properties of concrete masonry into the design. For partially grouted walls where the unfilled cells are aic empty, the equivalent thickness for fire resistance rating purposes is equal to that of an ungrouted unit.
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The following proportions were used for 2116.1 Buildex and sand: It is a multi-functional system in a single package:. The calculated equivalent thickness of a concrete masonry wall may include the thickness of applied plaster and lath, gypsum wallboard, or gypsum plaster. The list of approved materials includes: Plaster and stucco need 2161 be applied in accordance with the provisions of the building code. It is the responsibility of the user to obtain engineering or other advisory services from licensed professionals as the basis for incorporating into any project any information, detail, or product offered herein.
Angelus Technical Article: Fire Resistive Ratings
The fire resistance ratings for lightweight units were calculated by linear interpolation using two steps, as illustrated in Table 4 below. 21.61 publishers of directories that list classified assemblies.
Certain finishes deteriorate more rapidly when exposed to fire than when on the non-fire side of the wall. The strength, purity, thermal stability, and insulative wci of Buildex aggregate make it an excellent performer in fire exposure, both in poured concrete and SmartWall masonry. Concrete masonry is a preferred material for use in constructing fire-resistive walls.
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