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Abstract. Three kinds of repair methods of cracked concrete floors are presented in the paper. One of them, based on coating using of polymer-cement composites, is discussed with presentation of the influence of different amount of styrene-butadiene co-polymer dispersion additive onto the shrinkage and strength. The next two correspond to injecting repair methods. There are also presented two different approaches in repair bonding of damaged floors. Following these ideas, results of testing of epoxy and polymer (PU) bonding of cracked specimens made of concrete and polymer-cement composites are discussed. Proposed new repair polymer flexible joints introduce energy dissipaters which allow protecting concrete pavements against large deformations. Presented comparisons of results indicate that the use of flexible polymers in repair process is efficient, what was confirmed by tests and observations of repair done at the KRK airport concrete pavement.

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Numerous concrete and reinforced concrete structures (industrial floors, petrol station or manoeuvring park pavements, elements of sewage system) are subjected to danger of permanent or periodical action of petroleum liquids that often causes the considerable reduction in concrete strength as well as decrease of bond between concrete and steel, which usually results in structure damages. The subject of the paper is estimation of influence of polymer dispersion additive (styrene-acrylic co-polymer and styrene-butadiene latex) onto durability of concrete subjected to action of different types of light liquids. The influence of polymer dispersion additive was confronted with the action of silica fume usually applied for sealing the structure of concrete. In the paper there are presented tests results for different types of light liquids onto such cement-polymer concrete properties as: strength, penetration depth of light liquids into material structure.

In the present article, the research results of concretes modified with a polymer dispersion of vinyl-benzene and acrylic (PC1) and with a styrene–butadiene dispersion (PC2) are discussed. Concretes were exposed to diesel, non-ethylated fuel, and the standard mixture of light liquids for 1000 h. Concretes modified with polymer dispersions, especially with the styrene–butadiene dispersion (PC2), indicated a smaller degree of liquid penetration into the depth of samples compared to the control concrete. The compressive strength for tested concretes, determined after 1000 h of storage in crude-oil products, in comparison to the strength of samples stored in de-mineralized water was significantly decreased, with the maximum differences equal to 12% for PC2 concrete.