Automated fatigue testing device for assessing performance of sealant jointing products

A description of the sealant jointing product test device is given herein that includes information on its operation and results from its use in subjecting sealant products to fatigue resistance tests. In the first instance, a novel benchtop sealant test device was developed that permits assessing the expected long-term performance of joint sealant products. This sealant test device can be used to conduct bench-scale testing indoors in a laboratory setting or outdoors whereby sealant products are exposed to weathering effects while undergoing movement. The device also includes a load cell that permits monitoring the load imposed on the products while undergoing movement; thus, changes in the resistance to movement can be monitored over time. Cyclic movement programs can be run once input to the device, and the rate of movement can be set at predetermined levels. In a subsequent development stage, the durability of sealed joints was verified with the use of the testing device. The effect of the curing condition and stress relaxation of sealants during joint movement were continuously monitored over the course of a daily cycle or a 12-s cycle of compression-tension with the device's load cell. Results showed that over the curing period the sealant joint was damaged, as evident from changes in the cross-section of the sealed joint and reduction in stress of the jointing product. It is likely that this would influence the fatigue resistance of the sealed joint. In addition, in respect to the stress relaxation of sealants, the rate of decrease in the compressive load compared with the initial load is larger than that of the decrease on tensile load; as such, to properly evaluate the fatigue resistance of sealed joints, it is desirable to carry out a program of cyclic joint movement.Peer reviewed: YesNRC publication: Ye