Structure and properties of hardened cement paste with modifying agents

At present the durability of concrete is standardized by such indirect indicators as the quality of materials used, and the concrete and reinforced concrete technology. The regulatory documents determine concrete density indicators depending on the operating environment. The purpose of this research is to identify the role of the most common modifying agents in the formation of the structure, properties, and durability of artificial stone. It has been revealed that the maximum resistance to cyclic effects is achieved only through the simultaneous introduction of water-reducing and pozzolanic additives, which ensure the stability of the structural characteristics of hardened cement paste. During the operation of reinforced concrete structures in aggressive environments, the cause and the degree of aggressive character are determined, and primary, secondary and special protection are designed. Modification of hardened cement paste with polycarboxylate ether and microsilica additives contributes to the formation of hydrosilicate phases in the form of an uncrystallized gel or slightly crystallized gel-like C-S-H(I) phase with C/S = 1.1-1.3, and separate inclusions of calcium hydroxide are observed.