Issue 29

S. de Miranda et alii, Frattura ed Integrità Strutturale, 29 (2014) 293-301; DOI: 10.3221/IGF-ESIS.29.25 297 stiffness). In this regard, in the work by Lignola et al. [6] the authors highlighted the influence of tile-joint details on the adhesive stress distribution and the need to account for these details. Moreover, the use of the proposed discrete approach allows to account for the presence of partial/eccentric inter-tile groutings that are a common typology of workmanship defects in tiled floors. Figure 4 : Grouting-Adhesive-Substrate discrete model. N UMERICAL R ESULTS Case study n this section some numerical examples are presented to show the capability of the proposed model to predict the response of a flooring system subjected to substrate shrinkage. The analysed flooring system is composed of 8 tiles with interposed groutings laying on an adhesive stratum attached to the substrate (Fig. 5). The mechanical and geometrical properties of the flooring are listed in Tab. 1. The presence of a localized defect is assumed by considering two different grouting configurations located at midspan of the flooring (Fig. 5): - Partial Grouting Bottom (PGB): partial grouting in low eccentric position with respect to the tile axis; - Partial Grouting Top (PGT): partial grouting in high eccentric position with respect to the tile axis. In addition, the case with no defects (FG) has been considered. Details of the partial grouting configurations are given in Tab. 2. Length [mm] Thickness [mm] E [GPa] ν Tile 600 8 49 0.18 Adhesive 4848 3 6.5 0.22 Substrate 4848 40 30.7 0.21 Grouting 6 8 19 0.2 Table 1 : Case study. Geometrical and mechanical parameters. For the PGB configuration, two different grouting lengths (2 mm and 6 mm) have been considered. In all the analysed cases, uniform substrate shrinkage 4 0 5 10     mm/mm is imposed along the substrate longitudinal direction. The chosen value of substrate shrinkage is a typical value for concrete structures [10]. I