MODIFICATION OF NON-AUTOCLAVED FOAM CONCRETE WITH PEAT ADDITIVE TMT600

Abstract

The authors have studied the effect of a thermally modified additive based on peat TMT600 on the properties and structure of foam concrete of non-autoclave hardening and proposed a model of a fragment of the structure of the gas–solid–liquid interface and a model for the formation of a porous structure of foam concrete of non-autoclave hardening. The paper reveals the mechanism of the role of the foaming agent in formation of the porous structure of foam concrete. Tomography methods have shown that the real structure of foam concrete corresponds to the proposed models, as well as the achievement of a uniform distribution of pores by volume. It was established that in hydration after the dissolution of tobermorite and ettringite, the cement particles are recharged, and, consequently, the electrokinetic potential changes from positive to negative values. The mass transfer of particles is carried out not only by diffusion, but also by convection during foam formation. The accelerated movement of particles can also be carried out due to the electrostatic interaction of charges both on the surface of the foam and the peat additive. The geometry of the structural cells of the foam has the form of polygons, consisting mainly of hexagons and pentagons. As a result of the ongoing processes, a complex hierarchical structure is formed, in which the Plateau–Gibbs channels in the foam are calmed (clogged), forming a stronger skeleton, and after cement hydration, due to the recharging of the surface of the latter, an interpore partition of increased strength is eventually formed with a simultaneous uniform distribution of pores in foam concrete structure. The developed wall material has not only high strength, frost resistance, but also increased thermal insulation properties. The foam concrete obtained with the use of the TMT600 additive fully meets the seven fundamental criteria of the modern concept of building materials science, such as: technological availability and efficiency, energy and resource saving, environmental safety and natural compatibility, economic feasibility, ethical acceptability of practical application, aesthetic expressiveness and social orientation.

Keywords

• foam concrete
• thermally modified peat additive tmt600
• foam expansion and stability
• structure formation
• tomography