MOSCOW, November 8. /TASS/ Researchers from the Peter the Great Saint Petersburg Polytechnic University (SPbPU) have created a new technique for determining freeze-thaw resistance for construction materials, as well as massive concrete and reinforced concrete structures, said the SPbPU media center.
According to the press release, the technique developed by the university is of vital importance for Russia’s import substitution program which requires building social and civilian infrastructure facilities with construction materials produced in Russia.
At present, all methods for determining the freeze-thaw resistance are very labor-and time-consuming. The SPbPU researchers have pointed out that although many new types of concrete are being put out on the market now, very often nobody checks the freeze-thaw resistance of the new materials due to the high complexity of tests.
Current tests require multiple heating and cooling cycles of the materials under examination. This makes the freeze-thaw resistance assessment a number of cycles which the material can withstand without suffering a notable loss in its durability. Researchers have suggested replacing the bulk of the heating-cooling cycles with mechanical treatment cycles which should not lead to any deterioration in accuracy.
This innovative approach has been tested on ordinary Portland cement by compressing the sample. Scientists then measured the extent of the damage caused by the mechanical treatment. They found out that the suggested testing method makes it possible to reduce the number of samples from 50 to 10, and for cutting the number of required thermal cycles from 100 to 5. The deviation of a deliverable freeze-thaw resistance parameter with those deduced classically is about 2%. Now, the new test is undergoing an examination to acquire a patent.