RESULTS: Cycled (Hydration/Dehydration) Submersion Tests of Hydrophilic Compounds

Test Scope:

To measure the comparative changes in volume and weight of EXPAND-Tite and a clay-based, traditional hydrophilic compound following cycled periods of hydration and dehydration.

Testing Method:

Same-size (3/4"H X 1"W X 4"L) samples of the two hydrophilic compounds were immersed in water for five (9-day) cycles of total submersion, each followed by a (5-day) cycle of drying.

Evaluation Methods:

Each specimen was evaluated by both quantitative and qualitative standards.

Quantitative Standards:

The volumetric change standard was based on measuring dimensional changes over the period of exposure. The weight change standard was based on weighing each specimen and recording any gains or losses at specified intervals.

Qualitative Standards:

The qualitative standards for both volumetric and weight changes were the same, with each being based on observable changes in the overall appearance of the test specimens following the various cycles.

Quantitative Results:

At the end of five 9-day cycles of hydration (each followed by a 5-day cycle of dehydration)...

The clay-based sample...

• had increased in volume by 65.84%
• had increased its weight by 13.63%
  

The EXPAND-Tite sample...

• had increased its volume by 11.99%
• had increased its weight by 8.62%.
  
  

Qualitative Results:

Our experience shows that significant increases in volume and weight (such as that registered by the clay-based product) result in excessive swelling, splintering, cracking and the eventual deterioration of the product.

Test Conclusion:

The Table of Weight Changes clearly demonstrates the significant "swings" in weight of the clay-based product during these cycle tests. This is caused by the high porosity of typical clay-based products, which allows them to rapidly take on and eliminate water. Such rapid changes in hydration appear to accelerate the deterioration of the product, which could lead to premature joint failure.

Based On Laboratory Measurements Of Changes In Volume And Weight of Identically-Sized Samples

(2) During the first 5-day dehydration cycle, white particles became visible on the surface of the clay-based product and the cracks became larger.

(3) When the clay-based product became fully dried during the second 5-day dehydration cycle, it began to crack and small pieces of the sealant fell off.

(4) During the third 9-day hydration cycle, cracking formed along all edges of the clay-based product and those cracks already formed became larger.

(5) During the third 5-day cycle of dehydration, the surfaces of the dried clay-based product looked like a dry river bed. Small pieces of the sealant continued to fall off.

(6) During the fourth 5-day cycle of dehydration, more pieces began to flake off the clay-based product.

(7) During the fifth 9-day cycle of hydration, more pieces of the clay-based product began flaking off. Both ends have opened up like a flower blossom.

EXPAND-Tite Compound showed no signs of cracking or other visible signs of deterioration.