EVALUATION OF PHYSICAL AND MECHANICAL PROPERTIES OF POROUS AGGREGATES FOR LIGHTWEIGHT CONCRETE

Subject: among the modern heat-insulating materials lightweight concrete on porous aggregates is widely used. Currently, porous aggregates are mainly represented by expanded clay gravel, which has some drawbacks in its physical and mechanical properties: high content of split grains and significant grain shape factor. The presence of split grains in expanded clay gravel leads to an increase in consumption of cement paste. Significant grain shape factor limits the use of expanded clay gravel in lightweight concrete of higher strength. Granulated foam glass is an alternative porous aggregate for lightweight concrete. It is characterized by high physical and mechanical properties and low values of thermal conductivity. Research objectives: in this article, the results of studies of physical and mechanical properties of expanded clay gravel and granulated foam glass are presented, the differences between these materials are revealed and the possibility of using granulated foam glass as a porous aggregate in lightweight concrete is studied. Materials and methods: properties of granulated foam glass and expanded clay gravel are determined according to the standards. Conclusions: according to the test results, it was found that granulated foam glass has higher values for a complex of physical and mechanical properties in comparison with expanded clay gravel, produced traditionally. However, the compressive strength test in the cylinder showed that the granulated foam glass has a significantly lower strength than the expanded clay gravel with the same value of their apparent density. Also during the tests, the possibility of using granulated foam glass to obtain a lightweight concrete corresponding to the grade class B5 and density class D1000 was established. In this case, there is a need to adjust the grain-size composition of the aggregate and component composition of concrete mixture.