APPLICATION OF EXPERIMENTAL-STATISTICAL MODELING TO EVALUATE INFLUENCE OF AMOUNT AND GRADING OF SAND AND REGIMES OF BURNING UPON COMPRESSIVE STRENGTH AND WATER ABSORBABILITY OF BUILDING CERAMICS

Abstract

ABSTRACT Procedure of formulating two experimental-statistical models of high level of complexity is discussed in this work. Their multiplicative form has been developed. These models allow to determinate the amount and grain size of weakening admixture in the form of sand and they also allow to determinate parameters of thermal treatment of ceramic mix for which required values of compressive strength and water absorbability are obtained. Original combined experimental design has been chosen to evaluate parameters of these models. Evaluation of experimental error which is necessary to evaluate adequacy of models and statistical significance of input parameters (coefficients) is discussed in this paper. Building ceramics is characterized by different features which depend on components of ceramic mix and ways of its mechanical and thermal treatment. This treatment decides of stone - like features of ceramics. High level of complexity of dependent physical, chemical and physico - chemical phenomena which occur in ceramic mix during burning makes it difficult to construct proper analytical theory which would enable to determine components of ceramic mix and parameters of thermal treatment in order to obtain product of required characteristics. In the given case there is a need to obtain calculation dependence of empiric or quasiempiric character. As a results of experiments the known effects of temperature and components, and the effects not described in literature have been obtained as well. Among these unknown, combined effects of grain size of wakening admixture, its amount in ceramic mix and burning temperature upon considered features should be mentioned.