Search

Abstract The paper deals with the structural behaviour of masonry arches strengthened through fibre reinforced composites with inorganic matrix (Textile Reinforced Mortar, TRM). Two innovative composites are considered: basalt fibre textile coupled with a lime-based matrix and carbon fibre textile associated with a cement-based matrix. Experimental results on bond capacity between composites and bricks and on the structural behaviour of unreinforced and extrados-reinforced, 1:2 scale masonry arches, tested under vertical load are presented. Experimental evidence is compared with outcomes obtained through an analytical model that exploits the stationarity of potential energy of acting forces within the assumption of large displacements. The effect of the reinforcement strip is taken into account retrieving the force-displacement relationship directly from experimental results of bond test. Results show that the analytical model provides a safety estimation of the peak load reached by the arch model during the test. Good agreement is found comparing the load-displacement diagram of the initial phases of the test and the estimations of the numerical model. It is highlighted that the bond force of TRM systems, experimentally determined on a straight substrate, offers capacity levels relevantly under those reached on a convex surface like the extrados of an arch. [ABSTRACT FROM AUTHOR]

• Seismic vulnerability of earthen-based buildings reinforced with timber elements. • Reliable model to evaluate the efficiency of traditional retrofitting elements. • Simple and compound (including side walls) overturning of walls. • Limit analysis assuming frictional interfaces or finite tensile capacity of masonry. • Case study, San Judas church, in Chile, survived several Mw > 8 earthquakes. Earthen architecture represents one of the most widespread built heritage and shows many advantages from both the environmental and economic points of view. Disadvantages connected to low mechanical properties of earthen structures are often overcome, in historical buildings, through the employment of timber elements, which can increase a box-type behaviour enabling both in-plane and out-of-plane mechanisms, facilitating spread damage and avoiding disastrous collapses. In this study, overturning mechanisms that can activate during earthquakes are investigated employing the tools of limit analysis. Through the kinematic approach of limit analysis, geometrical and mechanical parameters most influencing the response to horizontal actions are analysed assuming different material models for masonry, i.e. finite compressive or tensile strengths, and presence of frictional strength. Within this framework, the presence of timber reinforcing elements is modelled providing a reasonable analysis method and sound results. Aiming at validation, the church of San Judas Tadeo de Malloa (Chile), built with traditional, earth-based, timber-reinforced masonries, is analysed interpreting the damage pattern suffered after the 2010 Maule earthquake (Mw 8.8). The study adapts the robust procedures of limit analysis to the peculiarities of earth-based structures, highlights the crucial role of timber elements in the response to horizontal actions, especially in areas with high seismic hazard, and proves that the beneficial effect of timber reinforcing systems can be adequately interpreted through the proposed procedure. [ABSTRACT FROM AUTHOR]

Two masonry types with irregular texture are analysed to evaluate mechanical properties, sources of vulnerability and to design proper strengthening interventions. Direct surveying, laboratory and in situ tests were performed to evaluate morphological characteristics and mechanical properties. Experimental values were compared with results obtained from analytical and FEM homogenizations, which exploited automated image segmentation process to determine volume fractions and description of the Reference Volume Element. Strips of Glass Fabric-Reinforced Cementitious Matrix and transversal bars were considered and tested as strengthening solutions to overcome irregular masonries limits derived from multi-leaf structure highlighting levels of capacity improvement. [ABSTRACT FROM AUTHOR]