How subzero temperatures affect the hardening kinetics of epoxy compounds used in hydraulic engineering construction

Conclusions

• 1. Our investigations have revealed the feasibility of using epoxy resins as a cementing material for plastic-concrete, glues, and paints at subzero temperatures; this is of interest for hydraulic engineering structures and the like, constructed in Siberia and the Far North.

• 2. The structural strength of compounds hardening at −20°C decreases by a factor of 5–10 and the adhesion strength by a factor of 3, with a tendency to display a subsequent increase.

• 3. The use of solvents greatly reduces the strength, the adhesion strength is less markedly reduced. At −20°C solvents preserve the composition but the cohesive strength is zero, whereas the adhesive strength has a specific value; after 60 days the decrease is not more than double the value observed in the absence of a solvent.

• 4. A marked increase in the strength of the materialis observed in going from a negative to a positive temperatures; this is of particular importance for the use of epoxy compositions in construction work, including hydraulic engineering structures.

• 5. The use of triethanolamine and DÉG-1 resin has a very beneficial effect on the increase in compression strength, but a similar effect is not observed in tensile tests.

• 6. The indices of the degree of polymerization did not display characteristic features accompanying the structural strength of the compounds.