Development of nomograms for the prediction of inherent geometric defects in stone block pavements

Stone block pavements consist of discrete units placed closed together and embedded in a bound or unbound bedding layer according to a given laying pattern. Such pavements are widespread in historic and architecturally valuable urban centres. Design choices, including laying pattern, cross-sectional shape, and slope, are not exempt from causing inherent defects such as joint openings and height differences between adjacent elements, depending on the sizes of the individual stone blocks. Prior knowledge of the deviation of the actual surface from the ideal one allows such problems to be managed during the design, execution and validation phases of the work and is essential for resolving disputes between the client and the contractor. Following the analysis of a 3D virtual reconstruction of stone block pavements, the authors developed nomograms for the quantitative prediction of inherent geometric defects in relation to the parameters influencing their values.