An accelerated exposure and testing apparatus for building joint sealants

Abstract

The design, fabrication, and implementation of a computer-controlled exposure and testing apparatus for building joint sealants are described in this paper. This apparatus is unique in its ability to independently control and monitor temperature, relative humidity, ultraviolet (UV) radiation, and mechanical deformation. Each of these environmental factors can be controlled precisely over a wide range of conditions during periods of a month or more. Moreover, as controlled mechanical deformations can be generated, in situ mechanical characterization tests can be performed without removing specimens from the chamber. Temperature and humidity were controlled during our experiments via a precision temperature regulator and proportional mixing of dry and moisture-saturated air; while highly uniform UV radiation was attained by attaching the chamber to an integrating sphere-based radiation source. A computer-controlled stepper motor and a transmission system were used to provide precise movement control. The reliability and effectiveness of the apparatus were demonstrated on a model sealant material. The results clearly show that this apparatus provides an excellent platform to study the long-term durability of building joint sealants.

Durability assessment of structural sealant glazing systems applying a performance test method

“…Looking for means to "accurately quantify the effects of the environmental degradation factors in laboratory and field tests", [10] researchers developed laboratory and outdoor apparatuses for testing the performance and durability of building joint sealants and understanding ageing and fatigue mechanisms. [11,12] One test configuration allows for tensile and compressive strain control of small-scale specimens and in situ monitoring of the transmitted stress. [10] An evaluated engineering modulus was regarded as a suitable performance indicator.…”

Humidity affects the viscoelastic properties of supramolecular living polymers

“…4). We note that several works addressed the humidity effects in different systems and presented alternative setups for controlling it [39][40][41][42][43][44]. Here, by using the particular drying agent instead of only saturating the sample environment with a mixture of dry gas/wet gas, which is commonly used, especially in melts, we achieve a long-time control for the solutions.…”