Test Specimen

The configuration of the vertical and horizontal joint are illustrated in Fig. 7 and Fig. 8, respectively. The overall size of the test specimen was 610 mm by 610 mm (Fig. 7). The vertical or horizontal joint was located at the middle of the specimen (width 20 mm; depth 15 mm) that was sealed with a one-part

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polyurethane sealant[21] (white; no primer). The sealant was applied to a closed­cell polyethylene backer rod having a diameter of 25 mm and cured in labora­tory conditions (20 ° C; 35 % RH) for two weeks before initiating the test. The crack introduced in the jointing product was located approximately at mid­length of either the vertical or horizontal joint. The panel assembly, and sub­strate to which the sealant was applied, was made of transparent acrylic sheathing; this permitted visual observation of water penetration along the joint in different test conditions over the course of the investigation. One por­tion of the panel assembly was fixed to the test frame (Figs. 7 and 8; fixed

Sealant

(Initial joint width: 20mm, joint depth: 15mm)

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FIG. 7—Front elevation of test specimen showing 20 mm vertical joint and nominal degree of movement of transparent acrylic panel.

portion), the other was moveable thus permitting the width of the joint to be changed up to a maximum of approximately 25 % of a joint of 20 mm in width (i. e., ca. 5 mm).