Improving the strength and resistance of cement composites to the external environment by utilizing complex additives

摘要

The article discusses the influence of complex additives on the strength and resistance of cement composites to environmental impacts. One of the additives - PFM-NLK (concrete modifier)- a factory fabricated mixture of a superplasticizer with the addition of air-retaining and water proofing substances. Another one is a complex additive containing a superplasticizer, sodium tetraborate and boric acid.Common denominator is the content of the superplasticizer. It allows reducing the W / C ratio of the mixture thereby increasing the density and strength of the composite, and, accordingly, its frost and corrosion resistance. PFM-NLK water-proofing and air-retaining substances additionally work toward the formation of a material structure with increased frost resistance. The components of the other additive, boric acid and sodium tetraborate, form a borate buffer system, which leads to the softening of the “chemical impact” and thus further increases the corrosion resistance. The research findings revealed the effectiveness of complex additives and substantiated the regularity that if each factor is separatelyfacilitative forproperty improvement, then, when they are combined, the effect is multiplied. The PFM-NLKcomponents, when combined, contribute to obtaining a material structure with high frost resistance. An additive containing a hyper-plasticizer, boric acid and sodium tetraborate leads to an increase in strength and acid resistance.