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The formulas provided by the standards or available in the literature for the calculation of the elastic modulus don’t consider many variables that influence the results of flat jack tests such as, first of all, the influence of the wall thickness. In this paper, flat-jack tests were performed - in the laboratory - on masonry wall specimens having the same geometrical and mechanical properties but different thickness. Then, a numerical assessment by FEM was carried out in order to extend the experimental evidences to the case of masonry walls with large thickness. This study allows to more accurately predict the masonry elastic modulus by double flat-jack test and it provides important data useful for the research activity as well as for the engineering practice.
V. Alecci; A.G. Ayala; M. De Stefano; A.M. Marra; R. Nudo; G. Stipo. Influence of the masonry wall thickness on the outcomes of double flat-jack test: Experimental and numerical investigation. Construction and Building Materials 2021, 285, 122912 .
AMA StyleV. Alecci, A.G. Ayala, M. De Stefano, A.M. Marra, R. Nudo, G. Stipo. Influence of the masonry wall thickness on the outcomes of double flat-jack test: Experimental and numerical investigation. Construction and Building Materials. 2021; 285 ():122912.
Chicago/Turabian StyleV. Alecci; A.G. Ayala; M. De Stefano; A.M. Marra; R. Nudo; G. Stipo. 2021. "Influence of the masonry wall thickness on the outcomes of double flat-jack test: Experimental and numerical investigation." Construction and Building Materials 285, no. : 122912.
The European seismic code 8 (Eurocode 8) classifies buildings as plan-wise regular according to four criteria which are mostly qualitative and a fifth one which is based on parameters such as stiffness, eccentricity and torsional radius that can be only approximately defined for multi-story buildings. Therefore, such plan-regularity criteria need to be improved. ASCE seismic code, according to a different criterion, considers plan irregularity when the maximum story drift, at one end of the building structure, exceeds more than 1.2 times the average of the story drifts at the two ends of the structure under building static analysis. Nevertheless, both the ASCE approach and the threshold value of 1.2 need to be supported by adequate background studies, based also on nonlinear seismic analysis. In this paper a numerical analysis is carried out, by studying the seismic response of an existing r.c. school building. Static analysis is developed by progressively shifting the centre of mass, until the ratio between the maximum lateral displacement of the floor at the level considered and the average of the horizontal displacements at extreme positions of the floor at the same level matches and even exceeds the value of 1.2. Then, nonlinear dynamic analyses are carried out to check the corresponding level of response irregularity in terms of uneven plan distribution of deformation and displacement demands and performance parameters. The above comparison leads to check the suitability of the ASCE approach and, in particular, of the threshold value of 1.2 for identifying buildings plan irregularity.
V. Alecci; M. De Stefano; Stefano Galassi; M. Lapi; Maurizio Orlando. An Assessment of American Criterion for Detecting Plan Irregularity. An Overview of the SIGMA Research Project 2020, 215 -231.
AMA StyleV. Alecci, M. De Stefano, Stefano Galassi, M. Lapi, Maurizio Orlando. An Assessment of American Criterion for Detecting Plan Irregularity. An Overview of the SIGMA Research Project. 2020; ():215-231.
Chicago/Turabian StyleV. Alecci; M. De Stefano; Stefano Galassi; M. Lapi; Maurizio Orlando. 2020. "An Assessment of American Criterion for Detecting Plan Irregularity." An Overview of the SIGMA Research Project , no. : 215-231.
Composite materials have been widely used to strengthen masonry structures or to repair those damaged by earthquakes. While the effect of composite materials applied on undamaged masonry walls is widely investigated, their effectiveness when used to repair damaged ones still needs further investigations. This paper deals with the shear capacity of masonry panels repaired with carbon fiber reinforced polymer composites. In particular, masonry undamaged panels were tested under diagonal load up to failure, repaired with composite materials, and tested again. The repair technique proved its effectiveness, since the shear strength of the repaired specimens was similar to that of the original ones. The shear capacity of the repaired panels was computed with the approach provided by the CNR DT200 Italian guidelines. Within this framework, the cohesion of the masonry material was neglected for the evaluation of the shear capacity of the repaired panels to take into account for the pre-existing damage. This approach provides a satisfactory agreement with the experimental results.
Valerio Alecci; Sara Barducci; Angelo D'Ambrisi; Mario De Stefano; Francesco Focacci; Raimondo Luciano; Rosa Penna. Shear capacity of masonry panels repaired with composite materials: Experimental and analytical investigations. Composites Part B: Engineering 2019, 171, 61 -69.
AMA StyleValerio Alecci, Sara Barducci, Angelo D'Ambrisi, Mario De Stefano, Francesco Focacci, Raimondo Luciano, Rosa Penna. Shear capacity of masonry panels repaired with composite materials: Experimental and analytical investigations. Composites Part B: Engineering. 2019; 171 ():61-69.
Chicago/Turabian StyleValerio Alecci; Sara Barducci; Angelo D'Ambrisi; Mario De Stefano; Francesco Focacci; Raimondo Luciano; Rosa Penna. 2019. "Shear capacity of masonry panels repaired with composite materials: Experimental and analytical investigations." Composites Part B: Engineering 171, no. : 61-69.
Prediction of elastic modulus is crucial to adequately assess the structural response of existing masonry buildings. Elastic modulus can be determined on-site, by double flat-jack test, according to ASTM C1197 and RILEM TC 177-MDT.D.5 and in laboratory, by compression test, according to EN 1052-1. These two types of test are different in terms of test set-up, procedure, data processing and formulas for calculating elastic modulus. In this paper a comparison between the values of elastic moduli obtained from the above two types of test, according to the different approaches provided by Standards or available in literature, is presented and discussed. The research provides recommendations on how to determine reliable values of elastic modulus from double flat-jack test.
Valerio Alecci; Gianfranco Stipo; Alessandra La Brusco; Mario De Stefano; Luisa Rovero. Estimating elastic modulus of tuff and brick masonry: A comparison between on-site and laboratory tests. Construction and Building Materials 2019, 204, 828 -838.
AMA StyleValerio Alecci, Gianfranco Stipo, Alessandra La Brusco, Mario De Stefano, Luisa Rovero. Estimating elastic modulus of tuff and brick masonry: A comparison between on-site and laboratory tests. Construction and Building Materials. 2019; 204 ():828-838.
Chicago/Turabian StyleValerio Alecci; Gianfranco Stipo; Alessandra La Brusco; Mario De Stefano; Luisa Rovero. 2019. "Estimating elastic modulus of tuff and brick masonry: A comparison between on-site and laboratory tests." Construction and Building Materials 204, no. : 828-838.
In recent decades, many strengthening interventions on masonry elements were performed by using fiber reinforced polymers (FRPs). These advanced materials proved to be effective to increase the load-carrying capacity of masonry elements and to improve their structural behavior, avoiding the most critical failure modes. Despite the advantages of this technique compared to more traditional methods, FRP systems have disadvantages related to their low resistance to high temperatures, impossibility of application on wet surfaces, low permeability, and poor compatibility with masonry supports. Therefore, composite materials made of a fiber textile embedded in an inorganic matrix were recently proposed as alternatives to FRPs for strengthening historic masonry constructions. These composite materials are easier to install, have higher resistance to high temperatures, and permit higher vapor permeability than FRPs. The inorganic matrix is frequently a cement-based mortar, and the composite materials made of a fiber textile embedded in a cement-based mortar are usually identified as FRCM (fabric reinforced cementitious matrix) composites. More recently, the use of natural lime mortar as an inorganic matrix has been proposed as an alternative to cement-based mortars when historic compatibility with the substrate is strictly required, as in case of restoration of historic buildings. In this paper, the effectiveness of a fabric made of basalt fibers embedded in lime mortar matrix (Basalt-FRLM) for the strengthening of masonry arches is investigated. An experimental investigation was performed on 1:2 scaled brick masonry arches strengthened at the extrados with a layer of Basalt-FRLM and tested under vertical load. The results obtained are compared with previous results obtained by the authors by testing masonry arches strengthened at their extrados with FRCM and FRP composites. This investigation highlights the effectiveness of Basalt-FRLM in increasing load-currying and the displacement capacities of masonry arches. The Basalt-FRLM-strengthened arch exhibited higher displacement capacity when compared to arches strengthened with polymeric and cementitious matrix composites.
Valerio Alecci; Mario De Stefano; Francesco Focacci; Raimondo Luciano; Luisa Rovero; Gianfranco Stipo. Strengthening Masonry Arches with Lime-Based Mortar Composite. Buildings 2017, 7, 49 .
AMA StyleValerio Alecci, Mario De Stefano, Francesco Focacci, Raimondo Luciano, Luisa Rovero, Gianfranco Stipo. Strengthening Masonry Arches with Lime-Based Mortar Composite. Buildings. 2017; 7 (4):49.
Chicago/Turabian StyleValerio Alecci; Mario De Stefano; Francesco Focacci; Raimondo Luciano; Luisa Rovero; Gianfranco Stipo. 2017. "Strengthening Masonry Arches with Lime-Based Mortar Composite." Buildings 7, no. 4: 49.