ASTM D5405-98(R2021) pdf free download

ASTM D5405-98(R2021) pdf free download.Standard Test Method for Conducting Time-to-Failure (Creep-Rupture) Tests of Joints Fabricated from Nonbituminous Organic Roof Membrane Material
1. Scope
1.1 This test method covers laboratory determination of the time-to-failure (creep-rupture) of joints fabricated from nonbi- tuminous organic roof membrane material. The test method covers both T-peel and lap-shear joints subjected to constant tensile load under controlled environmental conditions. The joints, made from either unreinforced or fabric-reinforced membrane material, are prepared in the laboratory or sampled from roofs in service. 1.2 Sheet materials from which the joints are fabricated include vulcanized rubbers, nonvulcanized polymeric sheets, and thermoplastics. The bonding methods for joint formation include the use ofliquid-based adhesives, preformed tapes, and thermal and solvent weld processes. 1.3 The values stated in either SI units or inch-pound units are to be regarded separately as standard. The values stated in each system may not be exact equivalents; therefore, each system shall be used independently of the other. Combining values from the two systems may result in nonconformance with the standard. 1.4 This standard does not purport to address all of the safety concerns, if any, associated with its use. It is the responsibility of the user of this standard to establish appro- priate safety, health, and environmental practices and deter- mine the applicability ofregulatory limitations prior to use. 1.5 This international standard was developed in accor- dance with internationally recognized principles on standard- ization established in the Decision on Principles for the Development of International Standards, Guides and Recom- mendations issued by the World Trade Organization Technical Barriers to Trade (TBT) Committee.
4. Summary of Test Method
4.1 This test method is a creep-rupture test without mea- surement of specimen deformation. The time-to-failure, in hours, of joints fabricated from nonbituminous organic roof membrane materials is measured when subjected to constant deadweight loads under controlled temperature and humidity conditions.
5. Significance and Use
5.1 An important factor affecting the performance of joints of nonbituminous membranes is their ability to remain bonded over the membrane’s expected service life. Time-to-failure tests provide a means of characterizing the behavior of joints under constant load over time. 5.2 Creep is a sensitive index of rheological properties that depend on material, load, temperature, and time. Time-to- failure data that are obtained over a relatively short time period can evaluate one factor affecting a joint’s ability to withstand static loading over a relatively long time period. 5.3 Time-to-failure data for joints of nonbituminous organic roof membrane specimens can be used for the following: (1) to provide a measure of the load-carrying ability of the joint as a function of time at various levels of load, temperature, and relative humidity; (2) to characterize the joint with regard to factors affecting performance, such as surface preparation of the adherend, solvent-based adhesive thickness and open time, environment during adhesive application and cure, and tem- perature of thermal welding processes; and (3) to compare the effects of different bonding processes or adhesive bonding materials on joint performance. 5.4 While it is considered that the results obtained by this laboratory test may afford a measure of the performance of seams in service, provided that load, temperature, and humidity conditions are known, no direct correlation has been estab- lished.
6. Apparatus
6.1 Test Chamber, ofsufficient size to hold a minimum of15 specimens. The height of the chamber shall be sufficient to allow suspension of the deadweight loads and specimen deformation during testing. The chamber shall be structurally capable of supporting the loads anticipated during testing without appreciable deflection. N OTE 1—A minimum height of 600 mm [24 in.] is suitable for the specimen sizes described in this test method if they are not extremely extensible. A taller chamber may be needed if they are extremely extensible.