抄録
At the present stage of binding materials science development the possibility of low-clinker and non-clinker binding materials effective using with non-fired clay minerals is theoretically and practically proved. However existing views for clay raw materials role in such systems are mainly based on its role as a plasticizer of hardening systems which doesn’t participate in basic phase-formation processes. Based on modern positions of nanochemistry, accumulated knowledge and own research results we present data on physical-chemical research of "clay-SiO2-CaO-H2O" system. The possibility to eliminate a specific property of clay inversion due to the directed combination of raw mix hardening conditions for phase-formation irreversible reaction provision is shown taking into account clay mineral aluminosilicate core participation forming a strong stone. It is shown that when South Kazakhstan clay materials using the low-temperature calcium hydro- and alumosilicates formation is possible in "clay-SiO2-CaO-H2O" system. Hereat sample compression strength can reach 5 MPa in already 15 days of natural hardening. The model system was studied at mixing of clay, sand, slaked lime and an alkaline additive of sodium carbonate. Components mixing and grinding was carried out in a ball mill. Reached high dispersion of products and also the factor of mechanic-chemical activation ensured the beginning of phase-formation processes with participation of aluminosilicate core of a clay component. It is revealed that water function in such systems can be changed in time. One can assume that the rate of new phase appearance co-ordinates closely with water condition at disperse system transition into stone-like condition. It is realized only when sufficient degree of macroparticles closing is provided. In this case the interlayer water role can be double, i.e. positive or negative one, and this phenomenon predetermines possibilities of management with structural-rheological properties of similar systems in the area of high specific surfaces and concentrations. It was especially demonstrated at clay-composite formation under high pressure. Clay-composites of 60 MPa strength and with water resistance factor more than 0.9 are obtained at optimal water content and component dispersion ability. Samples with smaller surface activity (smaller fineness degree) with identical water content of a shaped mix displayed rheological properties at smaller pressing pressures. In this case loosely-coupled "film" water plays a role of a damping agent in the pressing moment in systems with contact- condensation hardening mechanism. It is like «capsulated» in intergrain space of formed structures and is in loosely-coupled condition. Such structures aren’t water-resistant ones and their strength is lowered. Using various production methods one can provide conditions for this loosely-coupled water consumption exclusively for processes of hydroxylation and new near-border aluminosilicate phase formation. In this case strong stone-like water-resistant structures are formed. Such simple techniques as the component ratio, mechanic-chemical activation of mineral particles allow to operate with thin chemical processes of clay-composite product production by the non-clinker and non-fired scheme.
