Optimization of proportions of a composite binder that has multi-component additives

Abstract

Introduction. The problem of increasing the strength and durability of Portland cement stone is not new, but it is still highly relevant. To improve the properties of the cement binder at the stage of manufacturing cement composites, finely dispersed additives of inorganic origin can be used. They affect processes of hydration and curing of concrete. Finely dispersed additives, being fillers of mineral and inorganic origin, compact the structure of the cement stone, and, consequently, concrete itself due to substantial porosity reduction. They also increase its strength, impermeability and frost resistance and reduce shrinkage. Besides, these additives allow saving clinker and improve the water-retaining capacity of concrete mixes, preventing their segregation, if used together with superplasticizers.
 
 Materials and methods. The effect of binder compositions on mechanical properties of a composite binder was studied using the Box-Wilson experimental design method. The compressive strength of cement stone was determined at the age of 7 and 28 days using the method of result processing according to GOST 30744–2001. The study was conducted at the laboratory of Department of Building Materials Engineering of Moscow State University of Civil Engineering.
 
 Results. The results are presented as the surface of the second level regression equation, describing the dependence of compressive strength of the cement stone on the composition of multi-component expanding and pozzolanic additives. The optimal composition of the mix, having multi-component additives, was obtained as a result of the experiments.
 
 Conclusions. In the future the authors will contribute the results of this study to their research into the properties of binders, containing multi-component expanding and pozzolanic additives.