Performance

From the point of view of the mechanical pressure tightness, various tests, performed in several independent European laboratories, have shown that the Corkseal hermetic protection can withstand pressures up to 0.5 MPa (4.93 atm) in negative thrust, if applied correctly. It should be noted that the product has exceeded even the test in the worst possible conditions, i.e. providing for the instantaneous application of the peak pressure of 0.5 MPa and before the hydro-expansive seals being minimally hydrated. The tests were carried out using a tubular spacer segment in rods of 2 metres, commonly available on the market, inserted in a cube of hardened concrete, to simulate the actual conditions of use. The tests of sealing under pressure under counter pressure were performed with a duration of peak pressure not less than 72 h. It should be noted that the seal, in case of installation of Corkseal in positive thrust, is certainly much higher, given the intrinsic geometry of the product.

The expansion tests where the expansive gasket of Corkseal was subjected, were performed using four different types of aqueous solutions: 

• demineralised water
• groundwater (obtained with the concentrations limit imposed by Legislative Decree 152/06: Ph 7.7 , sulphates 250 mg/l nitrate 50 mg/l, chlorides 200 mg/l, iron 0.2 mg/l, manganese 0.05 mg/l, nickel 0.2 mg/l)
• salt water (NaCl 3.6%)
• base solution Ph 12.0 (to simulate the conditions in contact with concrete) 

In the experimental tests of immersion in the solutions described, the product displayed a change in average volume at 30 days not less than 190%.