Improving bond strength and mass transport properties of spacer-concrete interface with textured spacers

Abstract Spacers are important devices used in all concrete structures to support reinforcing steel and achieve the required cover. However, spacers induce a weak, porous microcracked interface that facilitates ingress of aggressive agents. This paper aims address problem by developing method produce cementitious with range small-scale surface textures including grooves, squares, rectangles, hemispheres pyramids. The textured were cast Portland cement mortar or concrete, cured up 28 days, tested for tensile bond strength, accessible porosity mass transport properties. properties correlated characteristics establish effects texture on spacer-concrete interface. Results show promote mechanical interlocking thereby increasing resistance against microcracking pressure-induced flow. use certain can compensate negative spacers, achieving similar strength permeability monolithic without