Scratch tests with single diamond tools on reinforced concrete and its components for the analysis of the material separation

Abstract

Core drilling with diamond impregnated segments is a common process for the machining of
concrete or reinforced concrete. These materials are characterised by their structure consisting of
various components. This inhomogeneity influences the cutting process due to changing process
forces or varying chip formation. Therefore an analysis regarding the material separation of the single
components (cement stone, aggregates like basalt, steel as reinforcement) as well as of the
compound materials is necessary. As a basis to analyse the core drilling process and in order to
gain detailed knowledge concerning the material separation process of reinforced concrete and its
components, scratch tests with single diamonds and varying process strategies were conducted. In
analogy with the core drilling process, circular grooves were produced. For the scratch tests steel,
cement stone, basalt, high performance concrete and reinforced concrete were used as sample
materials. One test series was conducted on a machining centre with the focus on process forces
under varying process parameters such as cutting velocity or feed speed. Further experiments
focused on the analysis of the development of the scratches due to repeated scratching. For this
microscopic investigation a tribometer in combination with a large-chamber scanning electron
microscope was used.