Concrete Shrinkage Compensation

The prospectivity of obtaining low shrinkage foam concrete of 200–400 kg/m³ density from cement mix containing dehydrated sodium citrate and expansive sulfoaluminate modifier ESM has been established. The effect of shrinkage compensation reveals itself due to the synthesis under conditions of the foam-cement structure of low-basic hydrosilicates which are overgrown with jellylike materials generated as a result of interaction of cement components, ESM additive and sodium citrate with the formation of a new block structure which resists to shrinkage effects in the process of transition of the foam-cement frame of foam concrete to the elastic state. Such factors as water migration under the impact of the temperature gradient, which leads to destructive effects, moist shrinkage, swelling of pore walls under steam condensation etc., resist to the progression of formation of hardening foam concrete structure. Defining destructive processes in the production of foam concrete are heat- and mass transfer in humid porous solids and stresses caused by temperature expansion of the material. To obtain the uniform distribution of heat flows in the course of drying of foam concrete massive, it is necessary to achieve the simultaneous heating of its volume. This can be realized with the help of microwave radiation which ensures the uniform drying without shrinkage effects and noticeable cracks.

S.N. LEONOVICH¹, Doctor of Sciences (Engineering) (This email address is being protected from spambots. You need JavaScript enabled to view it.)
D.V. SVIRIDOV², Doctor of Sciences (Chemistry) (This email address is being protected from spambots. You need JavaScript enabled to view it.)
G.L. SHCHUKIN², Candidate of Sciences (Chemistry)
A.L. BELANOVICH², Candidate of Sciences (Chemistry)
S.A. KARPUSHENKOV², Candidate of Sciences (Chemistry)
V.P. SAVENKO², Senior Staff Scientist

¹ Belarusian National Technical University (65, Nezavisimosti Avenue, Minsk, 220013, Belarus)
² Belarusian State University (4, Nezavisimosti Avenue, Minsk, 220030, Belarus)

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