Evaluation of deterioration degree and consolidation effectiveness in sandstone and clay brick materials based on the micro-drilling resistance method

The quick and accurate measurement and evaluation of the deterioration degree and consolidation effectiveness on the surface of masonry relics is valuable for disease investigation and restoration work. However, there is still a lack of quantitative indices for evaluating the deterioration degree and consolidation effectiveness of masonry relics in situ. Based on the micro-drilling resistance method, new quantitative evaluation indices for the deterioration degree and consolidation of masonry materials were proposed. Five types of masonry samples with different deterioration degrees were prepared by artificially accelerated deterioration tests involving sandstone and clay brick as research objects. Three types of consolidants were used to consolidate the deteriorated samples. Drilling resistance tests were conducted for deteriorated and consolidated samples. The variations in deterioration depth and average drilling resistance for samples with different numbers of deterioration cycles were analysed, while the differences in consolidation depth and average drilling resistance for samples with different consolidant types and dosages were compared. Finally, the deterioration degree index ( <mml:math xmlns:mml="http://www.w3.org/1998/Math/MathML"><mml:mi>K</mml:mi></mml:math> ) and consolidation effectiveness index ( <mml:math xmlns:mml="http://www.w3.org/1998/Math/MathML"><mml:msub><mml:mi>R</mml:mi> <mml:mi>c</mml:mi></mml:msub> </mml:math> ), which are based on the average drilling resistance, are proposed. The results can be applied to quick on-site investigations of immovable masonry relics.