EXPAND-Tite Controlled Expansion Waterstop Sealant Cast-In-Place Joint Pressure Test

PURPOSE OF TEST
This test was performed to demonstrate the pressure-holding capabilities of a cast-in-place joint, assembled with EXPAND-Tite Controlled Expansion Waterstop over extended periods of time, under ever increasing hydrostatic pressures.

TEST PROCEDURE
Form A Precast Base First, a 14” diameter by 3” thick disk-shaped concrete base was precast with six equidistant pieces of 3/8” rebar, positioned 1-1/2” from the outer edge and protruding 1-1/2” from the top surface of the disk.

Once the base cured, the steel form was removed and a 1” wide strip of appropriate priming material was painted onto the top surface, on the inside of the protruding rebars.
A continuous strip of (3/4” x 1”) EXPAND-Tite Controlled Expansion Waterstop Sealant was pressed firmly onto the primed surface with the two ends of the sealant overlapped to form a uninterrupted seal. A sheet of 15# tarpaper (approximately .030”thick) was then cut to fit the areas inside and outside the applied sealant ring-to maintain a consistent gap between the precast base and the poured-in-place cap during the test. Form A Poured-In-Place Cap For The Base The steel form was clamped into position around the top edge of the poured base and a special steel water chamber, attached to standard plumbing fittings was positioned in the center of the base.

These fittings were later used to introduce water and air into the cavity as a test of the sealant’s ability to maintain hydrostatic pressure during the procedure.

(See Diagram 1)

Concrete was then poured into the form to a depth of 3” to create the cap of the test specimen. Once the cap cured for 48 hours, four threaded steel rods and clamping brackets were put into position around the circumference of the test assembly and tightened to hold the two specimens at a consistent distance from one another for the duration of the test. Pressurization The center cavity (and plumbing fittings) were filled with water and allowed to saturate for 288 hours (12 days) The hydrostatic pressure (as indicated below) was then applied controlled via regulated, compressed air- and maintained for the specified number of hours.

PSI HOURS
10# 168 (7 days)
25# 168 (7 additional days)
50# 168 (7 additional days)
75# 168 (7 additional days)
100# 5,640 (235 additional days)

TEST RESULTS:
After full pressurization for the number of hours shown above, EXPAND-Tite Controlled Expansion Waterstop Sealant showed no visible signs of deterioration. In addition, EXPAND-Tite expanded in a controlled fashion without excessive swelling. Such inordinate swelling could cause fractures or similar failures. These types of failures are not uncommon with sealants that expand excessively, which can place undue pressure on structural components.