Hydroactive expanded polyurethane

 

Hydroactive foam expanded urethane

“Aqvidur” one component expanded polyurethane waterproofing system.

One component expanded waterproofing systems are based on special isocyanate containing prepolymers characterized by perfect hydrophilic properties which allow to state that these prepolymers are watersoluble (before the beginning of reaction).

Expanded polyurethane urea (EPU) is a substance obtained in a result of the chemical reaction of forepolymers with water or waterflooded materials. Hardening (forming of EPU) is happening with immense water excess (up to thousandfold) and going by with its physical bonding. While EPU is forming there is no water separation which means that all water, existing in the system, is being chemically and physically bound. The fact that the given product is capable to harden, binding water, allows to use this product in building and repairing of underground constructions.

The property of one component expanded waterproofing systems to harden with various water excess resulting in forming of gel and foam plastic (filled gel or foam plastic) which is impermeable for unbound water can not be overestimated.

In contact with water “Aqvidur” is forming a jelly-like homogenious material. The more mass fraction of the forepolymer in jelly the more jelly’s strength is. After drying a caoutchouc-like material is left, which can swell in water but can not return to its initial state while being immersed into the water. In the moment of forming a degree of polymer immersion is 300%. After the drying process waterabsoption balance is from 100 to 600%. Jellies are stable in storage.

If water suspension is used instead of water than the reaction results in forming a filled gel which mechanical strength is determined by quantity and a type of the filler. Here is an example: during hardening of wet sand an artificial stone is obtained, which strength depends on EPU mass fraction.

The given product is very effective in application for concrete construction waterproofing where there is mobility of constructions that leads to periodical widening or contraction of cracks. Owing to gel elasticity there is no disturbance of its structure and bond with the wall of joints that provides good waterproofing of the construction.

Main applications:

Waterproofing of dynamic seams and cracks in building constructions;
Filling of cavities and voids in constructions and rock;
Strengthening of waterflooded ground.

Properties:

High durability.
Resistant to microorganisms and fungus.
Insoluble by water and most chemicals, resistant to aggressive media.
Ecologically friendly to people and environment.
There is no need to use complecated technological equipment while using Aqvidur.

Carrying out of waterproofing works

To inject a polymer composition in water-bearing or concrete massif in the places of cracks or water seepage it is essential to drill bore holes of necessary length (depth) where an injectior is put to inject one component expanded system into disturbed massif. To inject the composition it is obligatory to use pumps that can provide pumping of fluids with viscosity of to 2000mPa/s.

Pumping the product into the massif should be carried out by portions (depending on supposed degree of integral massif disturbance, degree of its waterflood and temperature) in definite time intervals (30 min) to exclude an outlet of unreacted product onto the surface. To achieve the same goal a bore hole mouth with inserted injector is plugged by old cloth (rags, etc.). Time of the materials hardening depending on massif temperature is:

with T from O to 10oC – up to 6 hours;
with T not less than 10oC – up to 2 hours.