Composite Aggregate for Lightweight Concrete Using Chrysotile Cement and Ash and Slag Waste

The composition has been developed and the physical and mechanical properties of a composite aggregate (CA) with a «core-shell» structure for lightweight concrete using chrysotile cement slurry (CCS) and ash and slag mixture (ASM) of a thermal power plant have been developed. A method for the manufacture of CA is presented, including the granulation of a core from CCS with a moisture content of 50–60%, the formation of a shell on the surface of the core by dusting it in a dry mixture with a specific surface area of particles of 320–340 m²/kg, prepared by joint grinding of Portland cement, acidic ash and slag mixture and pre-dried chrysotile cement slurry at a temperature of 110^оC, heat and moisture treatment of finished granules. Mathematical models of the dependence of the bulk density and compressive strength of the CA on the quantitative ratio of the components of the mixture for dusting the core and the moisture content of the CCS have been constructed. A rational composition has been proposed that makes it possible to obtain a composite aggregate for lightweight concrete with a bulk density of up to 380 kg/m³, thermal conductivity up to 0.09 W/(m·^оC), compressive strength up to 3 MPa, and water absorption by weight of 30%. The possibility of utilization of chrysotile-cement and ash and slag waste in the production of efficient and environmentally friendly aggregates for concrete with low bulk density and thermal conductivity has been substantiated.

N.P. LUKUTTSOVA¹, Doctor of Sciences (Engineering) (This email address is being protected from spambots. You need JavaScript enabled to view it.),
A.A. PYKIN¹, Candidate of Sciences (Engineering) (This email address is being protected from spambots. You need JavaScript enabled to view it.),
G.N. SOBOLEVA¹, Candidate of Sciences (Engineering) (This email address is being protected from spambots. You need JavaScript enabled to view it.);
N.V. ZOLOTUKHINA², Graduate student (This email address is being protected from spambots. You need JavaScript enabled to view it.);
A.A. OBYDENNAYA¹, Student

¹ Bryansk state engineering-technological university (3, Stanke Dimitrova Avenue, Bryansk, 241037, Russian Federation)
² Bendery Polytechnic Branch of the State Educational Institution «Pridnestrovian State University named after T.G. Shevchenko» (7, Bendery Uprising Street, Bendery, 3200, Moldavian Republic)

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