Fire resistance time

For the water-cooled beam and column specimens, after an increase of temperature in the first 20 min, temperatures progression approached a nearly steady-state condition in the following 70-100 min and a fire resistance time of more than 2 h could be achieved, satisfying the code-required 90 min fire resistance for most buildings. In the water-coohng system, the flow rates used were modest and apph-cable in real buildings. The increase of water temperature was small and the outlet temperatures remained well below boiling. 

The experiment was stopped because of the structural collapse of the specimen at 65 min after fire exposure started. The failure occurred due to the distortion and wrinkling of the web at the loading point and the CS board was also broken as a result of the failure of the GFRP profile. In comparison to the same GFRP profile without any fire protections, the fire resistance time improved by 71% (from 38 to 65 min). 

The development of the midspan defection of the GFRP profile with intumescent coating is shown in Figure 9.3 and compared to the ones with or without fire protections. The GFRP profiles incorporated with intumescent coating and cementitious mortar demonstrated similar time-dependent deformation responses and further showed very similar fire resistance times (76 min vs 74 min). However, the former... 

Except for fire-resistant fluids, synthetic lubricants have not captured a significant portion of the general lubricant or hydrauhc markets, primarily because the cost is two to four times that of other premium lubricants. However, development of satisfactorily formulated products continues. 

Foamed plastics (qv) were developed in Europe and the United States in the mid-to-late 1930s. In the mid-1940s, extmded foamed polystyrene (XEPS) was produced commercially, foUowed by polyurethanes and expanded (molded) polystyrene (EPS) which were manufactured from beads (1,2). In response to the requirement for more fire-resistant ceUular plastics, polyisocyanurate foams and modified urethanes containing additives were developed in the late 1960s urea—formaldehyde, phenoHc, and other foams were also used in Europe at this time. 

Elame-spread and smoke-density values, and the less often reported fuel-contributed semiquantitive results of the ASTM E84 test and the limited oxygen index (LOI) laboratory test, are more often used to compare fire performance of ceUular plastics. AH building codes requite that ceUular plastics be protected by inner or outer sheathings or be housed in systems aH with a specified minimum total fire resistance. Absolute incombustibHity cannot be attained in practice and often is not requited. The system approach to protecting the more combustible materials affords adequate safety in the buildings by aHowing the occupant sufficient time to evacuate before combustion of the protected ceUular plastic. 

The fire death rate in the United States is decreasing, dropping from a rate of 76 per million in the 1940s, when most constmction and decorative products were made of natural materials, to 29 per million in the 1980s, by which time, PVC had replaced natural materials in numerous appHcations (189). This downward trend can be attributed in large part to improved building codes and the broader use of sprinkler systems and smoke detectors. However, the increased use of more fire-resistant materials, such as PVC, deserves part of the credit for this improvement. 

Hemihydrate. The abiUty of plaster of Paris to readily revert to the dihydrate form and harden when mixed with water is the basis for its many uses. Of equal significance is the abiUty to control the time of rehydration in the range of two minutes to over eight hours through additions of retarders, accelerators, and/or stabilizers. Other favorable properties include its fire resistance, excellent thermal and hydrometric dimensional stabiUty, good compressive strength, and neutral pH. 

Such fluids often referred to as 5/95 fluid (that being the ratio of oil to water), have essentially the same properties as water with the exception of the corrosion characteristics and the boundary lubrication properties, which are improved by the oil and other additives. The advantages of this type of fluid are fire resistance, lower fluid cost, no warm-up time, lower power consumption and operating temperatures, reduced spoilage of coolant, less dependence on oil together with reduced transport, storage, handling and disposal costs, and environmental benefits. 

Doors present certain hazards, too, since a collision is likely to take place when two people approach a door from opposite directions at the same time. Even a small window in every door makes it possible to observe activities on the other side and prevent such problems. This may not be possible in those few cases where fire resistant doors are called for. 

Time-temperature curves for fire resistance for different types of materials are available from American Society for Testing and Materials (ASTM) Standard E 119 (Ref. 41). 

Ability to evacuate. Fire often develops over a time period sufficient to provide warning to occupants, and some buildings may provide adequate fire resistance or means of egress to permit evacuation. For other events that can develop over a period of time, such as a BLEVE or, in some circumstances, a VCE, and for which means of detection,... 

Organophosphate Ester Hydraulic Fluids. Organophosphate ester hydraulic fluids are used in applications that require a degree of fire resistance such as in aircraft. EPA (1992b) has noted that aircraft mechanics may have dermal exposures of 1,300-3,900 mg/day and that 2,200 aircraft workers are routinely exposed to tributyl phosphate, while another 43,000 mechanics may be exposed at various times. Estimates of worker exposure in other industries were not found in the available literature. General population and military personnel exposure to organophosphate ester hydraulic fluids is likely to be much lower than exposure to mineral oil hydraulic fluids because these fluids have more specialized uses. 

Following are some examples of passive safety systems to reduce the likelihood of explosions in storage units. The use of baffles in a high-pressure storage vessel can cool the tank wall above the liquid surface via liquid pumped around by vapor bubbles, extending the time for fire fighting. Fire resistant tank insulation is also effective in delaying a BLEVE. 

Fireproofing - A common industry term used to denote materials or methods of construction used to provide fire resistance for a defined fire exposure and specified time. Essentially nothing is fireproof if it is exposed to high temperatures for extended time periods. 

Passive protection can be used to increase the time to structural failure. For example, intumescent mastic coatings of less than 1 inch thickness have been shown to provide up to 4 hours of fire resistance when applied to steel columns. Cementitious materials have been shown to provide 1-4 hours fire resistance for thicknesses of 2.5-6.3 cm (1-2.5 in). For additional information on passive fire protection, see Chapter 7. 

Mastics are sprayed on a substrate in one or more coats, depending on the desired degree of fire resistance. The final coat of all fireproofing mastics should be rolled or brushed to provide a smooth surface finish. The material should be applied with a sufficient number of coats to prevent running or slumping and sufficient drying time should be allowed between coats. Mastics may also be hand-troweled, if permitted in the manufacturer s specifications. 

The material and its installation should be designed to protect for a specific time period. For hydrocarbon fire exposure materials and their installation are generally tested to either UL 1 709 or ASTM El 529 to determine time-to-failure of different thicknesses and installation methods. It should be noted that the fire resistance rating is a measure of the ability of the installed material to withstand a specific "standard" fire. While these conditions closely match those in any given hydrocarbon fire, during actual fires the material may be exposed to conditions that may be more or less thermal intense, thus it can be expected to retain its integrity for a greater or lesser time. 

Combination water spray with fire-resistive insulating material 1 to 1V2-hour rated fireproofing plus water spray (as above) 1 to 1V2-hour rated fireproofing plus water spray (as above) Active protection but the passive fireproofing allows some time of protection in event water system fails. 

Fire resistance rating—The time period that a specific fireproofing design will protect structural supports for equipment, piping and so forth from collapse, when exposed to a fire of specified intensity. The fire intensity is usually represented by a time-temperature curve. 

Waldo Semon was responsible for bringing many of the PVC products to market. As a young scientist at BF Goodrich, he worked on ways to synthesize rubber and to bind the rubber to metal. In his spare time, he discovered that PVC, when mixed with certain liquids, gave an elastic-like, pliable material that was rainproof, fire resistant, and did not conduct electricity. Under the trade name Koroseal, the rubbery material came into the marketplace, beginning around 1926, as shower curtains, raincoats, and umbrellas. During World War II, PVC became the material of choice to protest electrical wires for the Air Force and Navy. Another of his inventions was the SR patented under the name Ameripol that was dubbed liberty rubber since it replaced NR in the production of tires, gas masks, and other military equipment. Ameripol was a butadiene-type material. 

Fire Resistive Material and design of building construction meant to withstand the maximum effect of a fire for a specific period of time. 

Elements of group 2 also form alkaline solutions when mixed with water. Furthermore, medieval alchemists noted that certain minerals (which we now know are made up of group 2 elements) do not melt or change when put in fire. These fire-resistant substances were known to the alchemists as earth. As a holdover from these ancient times, group 2 elements are known as the alkali earth metals. 

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