Rock Breakability Assessment and the Impact of the Produced Aggregate on the Elastic Modulus of Concrete.

In engineering construction, rocks broken by mining and tunnel excavation are often used as concrete aggregates, and rock fragmentation influences the elastic modulus of concrete. To improve the efficiency of rock breaking and the application effects of rock aggregates, this work proposed a method for evaluating rock breakability and the impact of the produced aggregate on the elastic modulus of concrete. The breakability of rock and its impact on concrete performance were studied based on fractal theory. A physical parameter characterization method was proposed to quickly compare the difficulty of rock fragmentation, characterizing the breakability of rocks and the processability of aggregates. The relationship between the relative specific surface area of aggregates and their main physical properties was established. The influence of rock breakability on the elastic modulus of concrete was analyzed through laboratory tests of uniaxial compression on concrete. Results demonstrate that the content of firm components in the rock mineral composition is significant, and the particle content of the main mineral components is positively correlated with the relative specific surface area of the fragmented aggregates. The relative specific surface area of the aggregates is negatively correlated with the fineness modulus and apparent density of the aggregates and positively correlated with the stone powder content and crushing index. The relative specific surface area of the aggregates shows a linear decreasing relationship with the water-to-binder ratio and elastic modulus. For C30 (C40) concrete, the water-to-binder ratio increased by 19.4% (21.4%), and the static compressive elastic modulus increased by 22.5% (25.0%). This study provides a particular guiding significance for the rapid and effective breaking of rock bodies and the resource utilization of aggregates. [ABSTRACT FROM AUTHOR]