Modified Plasters for Restoration and Finishing Works

Abstract

The paper is devoted to the research and development of modified plasters for restoration and finishing works based on decorative multicomponent cements containing white Portland cement and supplementary cementitious materials (silica fume, metakaolin and fine ground limestone). This cements are similar to Roman cement by their chemical composition. The use of optimal granulometry of decorative multicomponent cements provide directed formation of microstructure of the cement matrix with the formation of stable hydration products. Compositions of modified plasters by the criterions of workability and compressive strength were designed. Physico-chemical modification of plaster by complex air-entraining admixture allows to obtain high-quality modified plasters with improved quality parameters.

Increase of brick masonry durability for external walls of buildings and structures

“…In the freshly-mixed mortar, spherical bubbles reduce the inner friction, plasticize and prevent its components from segregation. Due to the aeration, the building mortar is characterized by lower absorption ability, it is more resistant to atmospheric influences and more resistant to the multiple cycles of freezing and thawing, as water that freezes in the capillaries has the ability to penetrate into empty bubbles which prevent the cracking, and thus play the role of "buffers" -stress dampers [10]. According to the thermogravimetry data, in modified mortars comprising after 3 months of hardening in the air-dry conditions LOI=7.38 mass.%, the content of bound water equals to 3.10 mass.%, or in relation to cement -14.39 mass.%, the content of Ca(OH) 2 and CaСO 3 -2.80 and 7.27 mass.% accordingly.…”

“…The use of air entraining admixtures in building mortar excludes the addition of lime in their composition that provides the increased frost resistance of masonry without forming of salt efflorescence. The right choice of mortar composition determines the durability of masonry in different conditions of buildings exploitation [10,11]. It is widely used the method of surface impregnation by repel compounds, resulting the reduction of porosity and permeability of the material, improve the performance properties and increase the durability of brick masonry.…”

“…At the same time, the presence of channels in the minerals structure of the zeolite group and high porosity of zeolite tuffs allow active absorption of SO 3 . The building mortar modified with natural zeolites is characterized by good sorption properties due to their porous structure and can accumulate a sufficient amount of salt [7][8][9][10].…”

Performance of Low Carbon Modified Composite Gypsum Binders with Increased Resistance

“…The use of composite cements with a high content of active mineral additives of hydraulic and pozzolanic action provides significant reserves for reducing energy intensity and the carbon footprint of such binders. The high activity of ultrafine natural zeolite tuffs in the binding of lime and gypsum to the hydrated phases opens up the possibility of their effective use in composite cements [12][13][14][15]. Therefore the hydraulic properties of gypsum binders at the present level may be also provided by physico-chemical modification of their properties by means of organomineral additives of polyfunctional action, which have several positive effects due to a synergistic combination.…”

Study of influence of the alkaline component on the physico-mechanical properties of the low clinker and clinkerless waterproof compositions

“…This requires their repair and protection against aggressive action of chemically and biologically active media, electrical currents, potentials and charges. Cement mortars, dry mixtures, Portland cement clinker-based plasters are mainly used for repair and protection [1][2][3]. An effective variety of such materials is the Portland cement-based penetrating compositions which compact the surface concrete layers of the damaged installation [4,5].…”