Destruction of powder-activated concrete with fixation of destruction by a laser interferometer

Abstract

The article is devoted to the identification of the patterns of deformation and destruction of powder-activated concrete under the action of power loads. As research concrete, powder-activated concrete of a new generation was considered in comparison with materials of the old and transitional generations. To carry out such studies, laser holographic interferometry methods were used, the physical essence of which consists in recording wave fields synchronously with the application of the load reflected by the surface under study at various points in time and then comparing these wave fields with each other. Using the complete equilibrium deformation diagrams and 3D graphs, we determined the parameters of the diagram (cyclicity, ultimate tensile strength), and the parameters of surface deformation (photographs with waves of strains and cracks). Using laser interferometry methods, it was found that the introduction of microquartz, especially in combination with amorphous active silica fume, significantly delays the onset of microcrack formation in cement samples, which exhibit a uniform deformation field up to a stress level of 0.90–0.95 from destructive. A sample based on a cement-sand mortar without finely dispersed fillers distinguishes a lower level of crack formation, corresponding to a stress level of 0.5–0.6 from destructive ones, and with an increase in load, the fracture of the sample has a block character.

Keywords

• self-compacting concrete
• fracture testing
• sress-strain curves
• crack propagation
• laser interferometry