Carlo Poggi

Bio: Carlo Poggi is an academic researcher from Polytechnic University of Milan. The author has contributed to research in topics: Masonry & Ultimate tensile strength. The author has an hindex of 32, co-authored 120 publications receiving 3248 citations. Previous affiliations of Carlo Poggi include University of Milan & Leonardo.

Mechanical properties and debonding strength of Fabric Reinforced Cementitious Matrix (FRCM) systems for masonry strengthening

Abstract: Fabric Reinforced Cementitious Matrix (FRCM) composites are advanced cement-based materials often used for strengthening masonry or concrete structures. The system is usually composed of a dry grid of fibers embedded in a cementitious matrix enriched with short fibers. An important parameter for designing the structural reinforcement is the tensile load-bearing capacity of FRCM composites. For their heterogeneity, FRCM composites show an interesting mechanical behavior in tension, that depends on the properties of the components and of the bonding strength. These values could be estimated with mechanical models but must be validated experimentally by means of proper testing campaigns. In this work several FRCM materials made with different fiber grids were investigated. Four different types of fibers were considered: polyparaphenylene benzobisoxazole (PBO), carbon (C), glass (G) and PBO and glass (PBO-G) fibers and three different types of cementitious mortars. The behavior of FRCM under tension and the influence of the bond properties between the dry textile and the inorganic matrix are studied developing an extensive experimental program that included the characterization both of the materials components and of the composites. A series of push–pull double lap tests and pull-off tests were performed to determine the bonding properties of FRCM composites applied to masonry structures. The paper presents results and considerations that can provide background data for future recommendations for the use of FRCM systems in the rehabilitation of elements.

Experimental investigation of tensile and bond properties of Carbon-FRCM composites for strengthening masonry elements

Abstract: Fabric Reinforced Cementitious Matrix (FRCM) materials are composed of a dry fiber grid embedded in an inorganic matrix, which may contain short fibers. These materials are particularly well-suited for the reinforcement of masonry structures due to their high compatibility with the substrate, vapor permeability and durability against environmental agents. The most important information needed for the characterization of these composite systems, for use as strengthening materials of masonry structures, are the tensile behaviour and the shear bond properties. A Round-Robin Test was organized by the RILEM Technical Committee 250-CSM and the Italian association Assocompositi in order to experimentally characterize different FRCM systems composed of PBO, carbon, glass, basalt, aramid and steel textiles embedded in cementitious or lime-based mortars. The systems were tested at different universities and research centers in Europe in order to investigate the influence of samples preparation, test set-up and instrumentation. In this paper, the experimental tests performed on Carbon-FRCM systems are described and discussed. Important aspects are analyzed herein: differences in the testing procedure and instrumentation, influence of textile geometry and mechanical properties of the constituent materials, importance of specimen preparation and curing conditions. Moreover, a comparison between tensile and shear tests is reported in order to determine a reliable procedure towards the complete characterization of an FRCM material.

An experimental, analytical and numerical study of the static behavior of steel beams reinforced by pultruded CFRP strips

Abstract: The paper presents the results of an experimental and numerical programme to characterize the static behaviour of steel beams reinforcement by pultruded carbon fibre reinforced polymer (CFRP) strips. Traditional H shaped steel beams with different CFRP reinforcement geometries bonded to the tension flanges using different epoxy adhesives were tested under three points bending configuration. Beams were not naturally or artificially corroded or notched but they were in good conditions before testing. The mid-span deflection and the strain along the whole CFRP lamina were recorded as function of the applied loading. The main objective of the experimental programme was the evaluation of the force transfer mechanism, the increment of the beam load carrying capacity and the bending stiffness. It allowed also to validate different analytical and numerical models for the static analysis of reinforced beams. In particular, a finite element model validated against the experimental data is presented.