请注意:此版本的所有临时修订版将在您购买时提供。建筑接缝系统耐火性试验SUL 20791范围1。1这些试验适用于各种材料和结构的接缝系统，用于相邻耐火结构之间的线性开口。1.2接缝系统的耐火等级旨在记录火灾暴露期间的性能，不应解释为已确定接缝系统在火灾暴露之前或之后的可接受性。 这些方法的目的是开发数据，以帮助其他人确定需要耐火的接头系统的适用性。1.3这些要求旨在评估1.1中规定的接头系统类型在预定试验暴露期间包含火灾的时间长度。该测试评估了接头系统的耐热性，在某些情况下，还评估了接头系统对软管流的耐热性，同时，如果总成是承重的，则评估接头系统在承载施加荷载时的耐热性。试验方法还包括可选的空气泄漏试验，以确定通过接头系统的空气泄漏率，该泄漏率是由施加在接头系统表面上的特定气压差引起的。 1.4根据这些要求，接头系统应经受标准的火灾暴露，以在规定的时间内达到规定的温度。这种暴露本身并不代表所有火灾条件；条件随火灾荷载的数量、性质和分布、通风、隔间大小和配置以及隔间散热特性的变化而变化。1.5所有接缝系统在火灾暴露前在其预期移动范围内循环，以证明接缝系统的移动范围，以及移动期间接缝系统对相邻耐火结构的影响。 在火灾试验期间，要求将接头系统加载至其设计活载能力。对于墙对墙和墙头接缝系统的试验，火灾试验后应使用规定的标准软管流。1.6这些要求包括测量通过热和气体联合系统的传输，热和气体的温度足以点燃废棉。1.7这些要求提供了在这些规定的火灾暴露条件下可比组件防火性能的相对测量。与所测试结构或条件的任何变化，如组装方法和材料，不在本测试方法的范围内。 1.8在ASTM C719《循环运动（霍克曼循环）条件下弹性填缝料附着力和内聚性的标准试验方法》中，对非火灾条件下用于接缝系统的浇注或成型就地材料的适用性进行了评估。1.9在非火灾条件下，评估接缝系统适用性的试验，而非浇筑或成型的就地材料，见ASTM E1399/E1399M《建筑接缝系统循环移动和测量最小和最大接缝宽度的标准试验方法》。 1.10确定墙壁和地板每小时耐火等级的试验见《建筑结构和材料防火试验标准》UL 263。应允许使用标准UL 263来确定带有控制接缝的墙壁和地板的每小时耐火等级。1.11根据火焰传播速度确定建筑材料表面燃烧特性的试验见《建筑材料表面燃烧特性试验标准》UL 723.1.12。这些试验的结果代表了评估接缝系统防火性能的一个因素。 这些要求规定了用于比较接头系统性能的标准火灾暴露。应用这些测试结果来预测实际建筑结构的性能需要仔细评估测试数据。1.13试验方法还包括可选的空气泄漏试验，以确定通过耐火接头系统的空气泄漏率，这是由于在系统表面施加规定的空气压力差造成的。从可选空气泄漏测试中获得的结果以每平方英尺（每平方米）开口每分钟立方英尺（立方米/秒）表示。 这些结果旨在开发数据，以帮助有管辖权的当局和其他人确定接头系统的可接受性，并参考通过组件的空气流动控制。1.14试验方法还包括可选的漏水试验，以确定耐火接头系统在三英尺压头下抵抗水通过的能力。该方法不评估未固化关节系统抵抗此类暴露的能力。1.15还可为耐火接头系统确定L等级。 L等级基于通过试样的空气泄漏量。1.16还可以为耐火接头系统确定W额定值。W等级基于试样的耐水性。

Please note: All interim revisions for this edition available at time of your purchase will be included.Tests for Fire Resistance of Building Joint SystemsUL 20791 Scope1.1 These tests are applicable to joint systems of various materials and construction that are intended for use in linear openings between adjacent fire resistive structures.1.2 The fire endurance ratings for joint systems are intended to register performance during the period of fire exposure and are not intended to be interpreted as having determined the acceptability of the joint systems for use before or after fire exposure. The intent of these methods is to develop data to assist others in determining the suitability of the joint systems where fire resistance is required.1.3 These requirements are intended to evaluate the length of time that the types of joint systems specified in 1.1 will contain a fire during a predetermined test exposure. The test evaluates the joint system's resistance to heat and, in some instances, to a hose stream, while carrying an applied load if the assembly is load bearing. The method of testing also includes optional air leakage tests to determine the rate of air leakage through joint systems resulting from a specified air pressure difference applied across the surface of the joint systems.1.4 Under these requirements a joint system is subjected to a standard fire exposure controlled to achieve specified temperatures throughout a specified time period. This exposure by itself is not intended to be representative of all fire conditions; conditions vary with changes in the amount, nature and distribution of fire loading, ventilation, compartment size and configuration, and heat sink characteristics of the compartment.1.5 All joint systems are cycled through their intended range of movement prior to fire exposure to demonstrate the joint system's range of movement and the impact of the joint system during movement on the adjacent fire resistive structures. Joint systems are required to be loaded to their designed live load capacity during the fire test. For tests of wall-to-wall and head-of-wall joint systems, the fire test is followed by the application of a specified standard hose stream.1.6 These requirements cover the measurement of the transmission through the joint system of heat and gases sufficiently hot to ignite cotton waste.1.7 These requirements provide a relative measure of fire performance of comparable assemblies under these specified fire exposure conditions. Any variation from the construction or conditions that are tested, such as method of assembly and materials, is not within the scope of this test method.1.8 Tests for evaluating the suitability of poured or formed-in-place materials for use in joint systems under non-fire conditions are found in the Standard Test Method for Adhesion and Cohesion of Elastomeric Joint Sealants Under Cyclic Movement (Hockman Cycle), ASTM C719.1.9 Tests for evaluating the suitability of joint systems other than those with poured or formed-in-place materials under non-fire conditions are found in the Standard Test Method for Cyclic Movement and Measuring the Minimum and Maximum Joint Widths of Architectural Joint Systems, ASTM E1399/E1399M.1.10 Tests for determining the hourly fire endurance ratings of walls and floors are found in the Standard for Fire Tests of Building Construction and Materials, UL 263. Standard UL 263 shall be permitted to be used to determine the hourly fire endurance rating of walls and floors with control joints.1.11 Tests for determining the surface burning characteristics of building materials, based on the rate of flame spread, are found in the Standard for Test for Surface Burning Characteristics of Building Materials, UL 723.1.12 The results of these tests represent one factor in assessing fire performance of joint systems. These requirements prescribe a standard fire exposure for comparing the performance of joint systems. Application of these test results to predict the performance of actual building construction requires careful evaluation of test data.1.13 The method of testing also includes optional air leakage tests to determine the rate of air leakage through fire resistive joint systems resulting from a specified air pressure difference applied across the surface of the systems. The results obtained from the optional air leakage tests are expressed in cubic feet per minute (cubic meter per second) per lineal foot (lineal meter) of opening. The results are intended to develop data to assist authorities having jurisdiction, and others, in determining the acceptability of joint systems with reference to the control of air movement through the assembly.1.14 The method of testing also includes optional water leakage tests to determine the ability of fire resistive joint systems to resist the passage of water under a three foot pressure head. This method does not evaluate the ability of uncured joint systems to resist such exposure.1.15 An L rating may also be established for a fire resistive joint system. The L rating is based on the amount of air leakage through the test sample.1.16 A W rating may also be established for a fire resistive joint system. The W rating is based on the water resistance of the test sample.