Technology organic and inorganic substances 39 effective methods of reducing CO 2 emissions in this sector consists in reduction of the clinker factor by means of a wider use of supplementary cementitious materials (SCMs) [3, 4]. This practice also contributes to reduction of concrete price, raises its strength at later age of hardening and durability. At the same time, with introduction of SCMs, slowdown of strength gain kinetics is observed in the products based on blended cements [5]. According to EN 197-1:2015, main components of the conventional cement family include additives of natural and 1. Introduction Implementation of the concept of low-carbon development is an important component of strategic goals of the global economy. Cement industry has made significant progress in terms of production efficiency and technological processes. However, level of environmental pollution caused by cement production is steadily rising. It amounts to 2.34 Gt CO 2 /year, which relates to the current accelerating pace of construction in the world [1, 2].

Abstract. The current article is focused at efflorescence formation and durability of brick masonry. The chemical and phase composition, microstructure of efflorescence on brick and masonry mortar on exterior walls of buildings are studied. Improved properties of brick masonry for external walls of buildings are achieved by the use of masonry mortar based on multi-component cement, which contains zeolite. It is shown that the use of multi-component cement with low clinker content in the mortar reduces the content of calcium hydroxide and SO 3 . It is determined that synergistic combination of mineral additives of different groups with substantial reduction of cement clinker in cements containing zeolite, improves durability of brick masonry without efflorescence formation. Physic-chemical modification of mortar by complex air-entraining admixture allows obtaining high-quality modified mortars with improved quality parameters. The surface modification of ceramic bricks by silicon and acrylic compounds provides protection and durability of brick masonry of buildings and structure walls.

Sustainable development depends on a consistency of interests, social, ecological and economic, and that the interests are evaluated in a balanced manner. In order to reduce CO2 emissions, the conception of decreasing clinker factor and increasing the role of supplementary cementitious materials (SCMs) in the cementitious materials has high economical and environmental efficiency. The performance of clinkerefficient blended cements with supplementary cementitious materials were examined. The influence of superfine zeolite with increased surface energy on the physical and chemical properties of low-carbon blended cements is shown. Increasing the dispersion of cementitious materials contributes to the growth of their strength activity index due to compaction of cement matrix and pozzolanic reactions in unclincker part. In consequence of the early structure formation and the directed formation of the microstructure of the cement matrix is solving the problem of obtaining clinker-efficient concretes. Shown that low-carbon blended cements with high volume of SCMs are suitable, in principle, for producing structural concretes.

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The ways of reducing CO2 emissions in the cement industry were analysed for the purposes of implementation of the low carbon development strategy. The optimal solution to this problem is the technologically optimised blended cements with high volume of supplementary cementitious materials of various genesis and fineness. The design of eco-friendly blended cements was achieved by a synergistic combination of the main constituents such as granulated blast furnace slag, superfine zeolite, fly ash and limestone, as well as by optimisation of the their granulometric composition, taking into account their bimodal particle size distribution by volume and surface area. Moreover, the article presents the technical, environmental and economic benefits of using eco-efficient blended cements.