European experiences with sealants in service
Title: European experiences with sealants in service
Author(s): W. Bartels
Paper category : conference
Book title: International RILEM Symposium on Building Joint Sealants
Editor(s): A.T. Wolf
Publisher: RILEM Publications SARL
Publication year: 1998
Pages: 22 - 24
Total Pages: 3
Nb references: 1
Abstract: This paper represents the views of the author, who has been a sealant specifier and applicator over the past thirty years, on the importance of sealants in buildings.
Thirty years ago, the main products used in sealing building joints had been oil-, bitumen-, or butyl-based plastic sealants. Then, modern sealants based on polysulphide polymer appeared on the market. However, the initial experience with these new, elastic materials had been very painful. At the CIB congress in Oslo in 1968, many speakers told tales of failures and problems with these sealants, and there was a developing tendency to find other ways of weatherproofing joints without the use of gun-grade sealants.
The problem had been that newly developed sealants were not tested and approved according to the strains they were exposed to in the field. The test methods used by the sealants industry had been originally developed by the rubber industry. As a result, values for the elastomeric properties were determined, which were not relevant to field performance. For example, an elongation at break of 800%, as measured in the laboratory by a rubber test method, should not be used as the movement capability of the sealant in determining the necessary joint width. In the mid 60’s, agreement
was reached to accept a movement capability of 25% for the best performing sealants.
A particular contribution to the testing and specification of joint sealants was made by the German Concrete Association (Deutscher Betonverein). Under the chairmanship of Dr. Stiller, this association published the "Provisional Guidelines for the Testing and Evaluation of Joint Sealants" in 1967. Years later, the German Standard DIN 18540 "Joint Sealants in High-Rise Building Construction" was born of this paper. As a consequence of this early guideline and the later DIN standard, the failure rate in the field was substantially reduced. On the basis of this DIN standard, several other test
methods for sealants were developed later.
In 1975, the UEATC published a specification for building joint sealants on a European level. This open specification comprised all sealants based on either existing or future raw materials as well as all applications relevant to gun-grade building sealants. The author hopes that work within ISO TC59/SC8 will allow further development towards an open specification for sealants.
Online publication: 2003-05-25
Publication type : full_text
Public price (Euros): 0.00