Research on the relation between fracture toughness and corrosion layer of coal mine shaft concrete exposed to sulfate environment

The deterioration regularity of unstable fracture toughness of shaft concrete under sulfate attack and the increasing law of unstable fracture toughness of concrete maintained in fresh water was investigated by three-point bending beam test in order to evaluate the relationship between the bending capability and corrosion layer thickness of concrete in the auxiliary shaft of Linhuan Coal Mine. Experimental results indicated that exponential function could be a good fit for the relationship between unstable fracture toughness and corrosion layer thickness; unstable fracture toughness reduced slowly while the corrosion layer is thinner, and reduced obviously with a turning point at 90 days(while the corrosion layer is 10mm). Both compactness and unstable fracture toughness of specimens maintained in fresh water was improved, but not obviously. Based on the relationship through laboratory experiment, the fracture toughness of shaft concrete under sulfate attack or surrounding in water can be obtained without harming to the shaft lining. © Sila Science. All Rights Reserved.