BS 8449:2005 pdf free.Building and construction sealants with movement accommodation factorsg reater than 25 %——Method of test ford etermination of adhesion/cohesion properties at variable temperatures.
BS 8449 This British Standard specifies requirements for sealants with a movement accommodation factor (MAF)greater than 25 %, which are selected according to the procedures in BS 6213 and BS 6093 and are installed according to the procedures in BS 8000-16.
The following referenced documents are indispensable for the application of this document. For datedreferences, only the edition cited applies. For undated references, the latest edition of the referenceddocument (including any amendments) applies.
BS EN 26927, Building construction —Jointing products — Sealants — Vocabulary.
BS IS0 13640, Building construction —Jointing products — Specifications for test substrates.
For the purposes of this British Standard, the terms and definitions given in BS EN 26927 apply.
Test specimens are prepared, in which the sealant to be tested adheres to two parallel contact surfaces.After submission to cycles of compression and extension under defined conditions, the test specimens areexamined for evidence of loss of adhesion or cohesion.
The substrates used shall conform to BS ISO 13640.Select the substrate material(s) from mortar, andor aluminium, andor glass, or from other substratematerials as agreed by the parties concerned.
For each substrate material, prepare three test specimens.
For each specimen, assemble two substrates (5.1) and two spacers (5.2), as described by Figure 1or Figure 2, upon the anti-adherent material (5.3).
Follow the instructions of the sealant manufacturer concerning. for instance.whether a nrimer shouldbe used and the mixing procedure for multi-component sealants.
Fill the hollow volume formed by the substrates and spacers with the sealant, taking the followingprecautions:
a) avoid the formation of air bubbles;
b) press the sealant in order that it makes good contact with the substrates;
c) tool the sealant surface so that it is flush with the top faces of the substrates and spacers.BS 8449 pdf download.