Меліорація і водне господарство (May 2021)
Effect of the recipe on the properties of polymer-cement waterproofing mixtures
Abstract
The technological properties of polymer-cement mixtures and the physical and mechanical properties of polymer-cement waterproofing coatings, depending on their quantitative and qualitative composition: the ratio of cement:sand (C:S), water-cement ratio (W/C) and the content of modifying additives, have been investigated using the method of experimental-statistical modeling. As a result of the implementation of B3 plan and the processing of experimental data, experimental statistical models were obtained that express the effect of the recipy on the properties of polymer-cement waterproofing mixtures and coatings: mobility, compressive strength, bending strength, adhesion and impact strength and water absorption. It was found that having the constant values of C:S and W/C modifying additives, namely redispersing polymer powder, powder polycarboxylate superplasticizer and microsilica are an important factor in the formation of the structure and properties of waterproofing coatings. The analysis of the models showed that the redispersing polymer powder and superplasticizer have a positive effect on he mobility of polymer-cement waterproofing mixtures, while silica fume has a negative effect on this indicator. The effect of modifiers on the physical and mechanical properties of waterproofing coatings is following: redispersing polymer powder and superplasticizer have a negative effect on the compressive strength, while microsilica increases this indicator; redispersing polymer powder and microsilica increase the flexural strength, while the superplasticizer has a negative effect on this indicator; all investigated modifiers increase adhesion and impact strength and decrease water absorption. Based on experimental-statistical models, diagrams were constructed, which are a graphical representation of the effect of the recipe on the properties of polymer-cement waterproofing mixtures, which enables to determine the areas of the recipe use with specified properties.
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