ECONOMIC EFFICIENCY OF USING CRUSHED CONCRETE WASTE AS AGGREGATE IN CONCRETE

Abstract

Large-scale destruction of buildings and infrastructure has resulted in the accumulation of substantial volumes of concrete and reinforced concrete waste, which necessitates not only organized disposal but also economically justified reuse within construction activities. Under conditions of limited availability of natural mineral aggregates, rising material prices, and increased costs of construction works, crushed  concrete waste is increasingly considered as a potential secondary aggregate capable of reducing material costs and improving resource efficiency. This study analyzes methods and techniques for the use of crushed concrete waste as a secondary aggregate in concrete works, taking into account technological aspects of processing, strength performance of concrete, and key economic factors influencing practical implementation. The research summarizes current approaches to concrete waste crushing, fractionation, and preparation, emphasizing the role of particle-size distribution and aggregate cleanliness in ensuring stable concrete properties. An experimental program was conducted to assess the compressive strength of concrete mixtures containing various combinations of traditional and recycled aggregates, including natural granite aggregate, crushed concrete, river sand, and beneficiation waste sand. The results indicate that concretes incorporating crushed concrete aggregates demonstrate a moderate decrease in compressive strength compared to reference mixes with natural aggregates; however, the obtained values remain sufficient for practical application in a wide range of concrete works with moderate structural requirements. The observed variability in strength characteristics is primarily associated with the presence of fine particles and residual cement paste in recycled aggregates, which affects interfacial bonding within the concrete matrix. From an economic perspective, the reuse of concrete waste is considered as an independent production and logistics process, the efficiency of which is largely determined by transportation costs, processing expenses, organizational factors, and the scale of implementation. The study concludes that, under rational processing conditions and appropriate quality control, crushed concrete waste can be regarded as a viable secondary resource that contributes to cost optimization, reduced dependence on natural aggregates, and improved overall resource efficiency of construction production, particularly in the context of large-scale infrastructure recovery.