MACROPOROUS FINE-GRAINED CONCRETE WITH USING OF STONE CRUSHING WASTE

Abstract

Macroporous concrete is a sand-free concrete, usually obtained from a mixture of gravel or crush stone with cement and water at limited content of cement paste. A feature of macroporous concrete is its unique structure with a larger volume of cavities between the grains, in contrast to classical concrete. The aim of the research was to study the influence of composition factors on the main properties of macroporous concrete (strength and density) made by vibropressing. The use as a aggregate of granite screening with monofractional composition suggests the possibility of obtaining concrete with an optimal combination of strength and density. To obtain quantitative dependences that take into account the influence of the main technological factors which define the macroporous concrete properties, experiments were performed using mathematical planning. After statistical processing, experimental-statistical (mathematical) models of strength and density of macroporous concrete were obtained.

It is established that the strength of macroporous concrete depends on the content and strength of cement stone. However, increasing the consumption of cement does not always lead to adequate strengthening of contacts between the grains of the aggregate. As follows from the analysis of the models, there is a certain optimum consumption of the superplasticizer from the standpoint of concrete strength.

It is determined that at optimal parameters of macroporous concretes composition it becomes possible to acquire strength and density values which allow them to compete successfully with traditional wall materials.