Recipe-technological features of carbonization hardening of lightweight concrete

The work is devoted to researching the parameters of expanded clay lightweight concrete technology by using carbonation hardening that allows to maximally intensify the process of carbonization using methods such as decreasing the total water content in the system, applying optimal structure and formula concrete compositions, processing the products in carbon dioxide environment. The mechanism of structure formation of concrete compositions in conditions of artificial carbonation was studied. It was formulated using the basic techniques of rational intensification of the hardening process. Rational formulation and technological parameters of carbonization technology of lightweight aggregate concrete wall products were proposed: effective replacement of almost 30 per cent of concrete by powdered lime rock in process of carbonization without changing the physical and technical properties of material; the optimal size of porous aggregates; the optimal modes of composite carbonization that include preliminary placement in vacuum and step processing in carbon dioxide environment. The maximum demoulding strength of expanded clay lightweight concrete was received by using maximum concentration of carbon dioxide during carbonization in reaction area that is characterized by the maximum pressure value. In addition, the properties of concrete in an early stage after the carbonization were explored.