Procedures

Three brands of cold liquid-applied waterproofing were generously provided by local suppliers. Two materials were one-component bitumen modified urethanes; these were designated 1UM-#1 and ШМ-#2. The third material was a two-component unmodified urethane, designated 2U-#1A.

Experienced waterproofing installers prepared samples in the unconditioned environment of a water­proofing contractor’s warehouse. Samples were cast as recommended by the manufacturer, in an applica­tion intended to produce a dry film thickness of 1.5 mm (60 mils). Specimens were prepared on release paper and remained in the warehouse for three days until they could be transported. The exterior condi­tions at the time samples were prepared and initially cured ranged from 8° to 16°C (46° to 61°F).

After conditioning, specimens 160 by 250 mm (6.3 by 9.9 in.) were cut from the sample material, weighed, and measured. Samples were subject to a four-week cycle of wetting and drying; as described in Table 7. The cycle was then repeated during the test period of 84 days. Weight was measured at the end of each week of water immersion or drying. Dimensions were measured through the first cycle only.

For the first set of specimens, the test cycle began with no additional conditioning after the three-day initial curing period. Following the initial three-day cure and prior to beginning their first test cycle, the second set of specimens was conditioned at standard conditions (23°С (73.4°F)) at 50 % RH) for seven days. The third set of specimens began their first test cycle after 14 days of conditioning at standard conditions and testing of the fourth set began after 21 days of conditioning at standard conditions.