Issue 46

L. Sorrentino et alii, Frattura ed Integrità Strutturale, 46 (2018) 285-294; DOI: 10.3221/IGF-ESIS.46.26 285 Performance Index of Natural Stones-GFRP Hybrid Structures Luca Sorrentino, Costanzo Bellini, Wilma Polini, Sandro Turchetta University of Cassino and Southern Lazio, Department of Civil and Mechanical Engineering, Italy luca.sorrentino@unicas.it, http://orcid.org/0000-0002-5278-7357 costanzo.bellini@unicas.it, http://orcid.org/0000-0003-4804-6588 wilma.polini@unicas.it , http://orcid.org/0000-0002-6839-3889 sandro.turchetta@unicas.it, http://orcid.org/0000-0002-8365-8910 A BSTRACT . Natural stone is a material that presents durableness over time and high aesthetic characteristic, but it is brittle and its tensile strength is significantly lower than compressive one: these peculiarities must be taken into account for material usage; in fact, for applications requiring high flexural and tensile strength, as thin sections or long spans, the particular mechanical behavior of the natural stone constitutes an issue to be overcome. A solution to the above mentioned problem is presented in the present paper: a natural stone tile is reinforced by bonding a sandwich structural laminate made of composite materials. In such manner, a double result is obtained: the mechanical strength increment and the and the tile specific weight decrement. In particular, two different types of sandwich structures, made of glass/epoxy laminates and honeycomb or foam core, were bonded to the lower surfaces of marble and granite tiles; then, 3-point bending tests were carried out on specimens extracted from the produced hybrid tiles. A performance index, considering both strength and weight of tiles, was introduced and the comparison with specimens extracted from traditional unreinforced tiles demonstrated that the considered reinforcement increases the structural characteristics of stone tiles up to an order of magnitude. K EYWORDS . Natural stones; Glass/epoxy sandwich laminate; 3-point bending test; Structural behavior improvement. Citation: Sorrentino, L., Bellini, C., Polini, W. and Turchetta, S., Performance Index of Natural Stones-GFRP Hybrid Structures, Frattura ed Integrità Strutturale, 46 (2018) 285-294. Received: 22.06.2018 Accepted: 08.08.2018 Published: 01.10.2018 Copyright: © 2018 This is an open access article under the terms of the CC-BY 4.0, which permits unrestricted use, distribution, and reproduction in any medium, provided the original author and source are credited. I NTRODUCTION or a long time, construction and in building furniture use natural stone. Only recently, the aesthetic properties of the stone are exploited to decorate the environments. All these applications are limited by the brittle nature and the consequent defects of the stone. In fact, the strength of stone in tension is considerably less than its strength in compression, the compressive strength of a rock exceeds its tensile strength by one to three orders of magnitude typically. This disparity limits the use of stone for long spans or thin sections, where tensile and flexural strength capacity is required. F