Minimum energy strategies for the in-plane behaviour of masonry

Abstract

Unreinforced masonry is the most diffused construction material in the major part of historical centers in Europe. In a building subjected to earthquake forces the contribution of in-plane shear resistance of the masonry walls is a determinant factor for the stability of the whole structure. In particular, the masonry piers are the structural elements subjected to the combination of normal and shear forces. In general, ductile tools to model the in plane behaviour of masonry are always welcome in order to evaluate the capacity of walls subjected to vertical and horizontal actions. In this framework, two no-tension approaches to model the behaviour of masonry walls loaded with in-plane forces, involving a minimum energy procedure, are presented. Both the procedures allow the representation of the stress maps in the panel in case of monotonic increase of shear load. The results of the numerical analyses are compared and discussed.

Sustainable Mortars for Application in the Cultural Heritage Field

“…As previously noted, the large number of tests performed by Vicat on lime mortars is not useful for this work because the pozzolan is not present as an aggregate in the examined samples [ 31 , 53 ]. The treatises in Table 1 were used as a reference for the mix proportions only, while a thorough discussion is provided comparing the laboratory tests performed by the authors with those present in literature and relative to pozzolanic mortar [ 54 ]. Three types of mortar specimens were prepared according to the proportions given in Table 2 .…”

“…Tensile and flexural tests were performed by a standard testing machine ( Figure 3 b) with a loading rate of 50 ± 2 N/s. The direct tensile tests have been performed bearing in mind that the recent developments of diagonal strut methods for the analysis of in plane behavior for masonry are often based on these values [ 54 , 55 , 56 ]. The choice of large side cubes is due to the exigence of modeling the behavior of rubble masonry in which the inner part of the wall includes a very large mortar element or Neapolitan tuff masonry, which sometimes involve thick horizontal joints.…”

Mechanical properties of traditional lime mortars

“…Since in several constitutive models for masonry the tensile strength plays a key role (Gesualdo et al, 2019(Gesualdo et al, , 2020, direct tensile tests on briquettes have been performed, although these tests have not been recently sufficiently considered in the recent ASTM standards for repair of historic masonry (ASTM, 2017). The mixture was placed in the moulds at 80% relative humidity, this last level maintained until the demoulding after 24 hours curing.…”

“…Lime mortars have been reconsidered for restoration, especially in combination with pozzolanic materials. On the other side, the development of numerical models for the analysis of masonry structures, in which the mechanical properties of mortar, in particular the tensile strength are essential features, whether for the in plane (Gesualdo et al, 2019(Gesualdo et al, , 2020 or the out of plane behaviour of masonry walls (Monaco et al, 2014;Guadagnuolo et al, 2009) has promoted deepening studies on these aspects . The mechanical properties of pozzolanic lime mortars are examined in this paper, taking into account the influence of different mix proportions respecting the classical treatises and different curing ages and conditions.…”

Building pathologies. Analysis of three case studies

“…As the history has pointed out, the behaviour of constructions is strongly linked to the workmanship and the good realization of the construction details. Differently from the cases in which the strength of the masonry wall is directly involved, like in the in-plane failure (Gesualdo et al, 2019 andMonaco et al, 2018b), local or global collapse can occur in fact due to pathologies arising during the construction or to bad realization of construction details (Buonocore et al, 2014;Gesualdo et al, 2020). This paper deals with this last aspect, examining three different masonry buildings: the first one is a brick masonry building in Bologna: San Barbaziano Church, the others are two Roman domus in two different archaelogical sites in Campania: Villa Regina, Boscoreale, Napoli and Villa dei Misteri, Pompeii, Napoli.…”