Effect of the addition of crushed concrete scrap on the kinetics of strength changes of cement-sand mortar
Abstract
Effect of the addition of crushed concrete scrap on the kinetics of strength changes of cement-sand mortar
Incoming article date: 08.03.2021The article deals with some of the most common waste from the construction industry. These are waste generated as a result of the construction of buildings and structures, concrete scrap. At the moment in Moscow in 2018, a programme of renovation, demolition of old housing, which estimates the amount of concrete scrap will amount to more than 14 million m3. The most effective way of recycling is using waste concrete scrap including eliminations of crushing in the manufacture of concrete. The problems of processing concrete scrap associated with the accumulation of a large number of screenings of concrete scrap, which is actually not used anywhere, are considered. Their number increases very much every year. As a result of the study, the chemical and mineralogical composition of ground concrete scrap was determined, as well as the grinding was performed up to Sud = 500 m2/kg. The possibility of using these ground wastes of concrete scrap (MOBL) as an active mineral additive (AMA) for the production of cement-sand solutions is considered. Due to the significant content of silica in these wastes in crystalline and amorphous form, these wastes can be classified as silica-containing. The kinetics of hardening of cement-sand solutions using active mineral additive was studied, histograms were constructed and conclusions were formulated.
Keywords: waste, construction industry, renovation, old place, concrete scrap, recycling, active mineral additive, mineralogical composition, cement-sand mortar, kinetics of hardening