BS ISO 13638:2021 pdf download – Building and civil engineering sealants — Determination of resistance to prolonged exposure to water

BS ISO 13638:2021 pdf download – Building and civil engineering sealants — Determination of resistance to prolonged exposure to water For the purposes of this document, the terms and definitions given in ISO 6927 apply. ISO and IEC maintain terminological databases for use in standardization at the following addresses: — ISO Online browsing platform: available at https://www.iso.org/obp — IEC Electropedia: available at http://www.electropedia.org/ 4 Principle Test specimens are prepared in which the sealant to be tested adheres to two parallel contact surfaces. After immersion of the test specimens in water under defined conditions, they are subjected to repeated extension and compression movements in a suitable device, at an amplitude which is 50 % of that used in the test to assess the respective movement accommodation factor. This procedure is repeated a number of times, or until failure of one or more test specimens is observed. The number of repetitions of water immersion followed by extension/compression movement is related to the expected water resistance in service. Water immersion may be carried out either at ambient temperature (23 °C), or at elevated temperature (40 °C or 50 °C) to accelerate the influence of the exposure to water. c) trim the sealant surface so that it is flush with the faces of the substrates and spacers. Set the test specimens on the edge of one of the substrates and remove the anti-adherent substrate as soon as possible. Let the specimens rest in this position to allow curing or optimum drying of the sealant. Maintain the spacers in place during conditioning. 7 Conditioning 7.1 General Condition the test specimens in accordance with either method A or method B, as agreed between the parties concerned. 7.2 Method A Condition the test specimens for 28 days at (23 ± 2) °C and (50 ± 10) % relative humidity. 7.3 Method B Condition the test specimens according to method A and then subject them three times to the following storage cycle: a) 3 days in the oven (5.4) set at 70 °C; b) 1 day in the container (5.5) filled with distilled water maintained at 23 °C; c) 2 days in the oven (5.4) set at 70 °C; d) 1 day in the container (5.5) filled with distilled water maintained at 23 °C. Alternatively, this cycle may be performed in the order c), d), a) then b). NOTE Method B is a commonly used conditioning procedure using...