On-site non-destructive test for sealants

Abstract

The degradation of sealants is defined as a change in physical properties caused by chemical reaction involving bond breaking in the backbone of macromolecules, and hence causes deterioration in the functionality of the polymeric material properties, such as elastic recovery and hardness. Currently, there is still no successful technique of determining the elastic recovery of in-situ sealant on building facades. Specifications and standards available are basically concerned with quality control in the manufacturing, and testing of new formulated products, and the design and application of sealants. They do not reflect and give adequate indications of the status of working sealants. Furthermore, the conventional laboratory testing techniques are tedious, time consuming and often destructive, which make them unsuitable for in-situ testing. This paper discusses the development of an on-site non-destructive testing technique to assess the performance of sealants on building facades. Assessment was made of the sensitivity, reliability and applicability of the tester. This is achieved by carrying out tests on various generic types of high-performance sealants subjected to natural and artificial weathering.