Archivi: Ricerche

Description

A number of experimental investigations were carried out to characterize advanced composite materials, such as Fibre/Steel Reinforced Polymers (F/SRP), Textile Reinforced Mortars/Fabric Reinforced Cementitious matrix (TRM/FRCM), and Steel Reinforced Grout (SRG). Experimental tests include direct tensile tests on bare textile specimens and composite coupons, as well as shear bond tests, performed with either single-lap or double-lap schemes.

Key publications on this topic

• De Santis S. Bond behaviour of Steel Reinforced Grout for the extrados strengthening of masonry vaults. Construction and Building Materials 2017;150:367-382. DOI: 10.1016/j.conbuildmat.2017.06.010.
• Tekieli M., De Santis S., de Felice G., Kwiecień A., Roscini F. Application of Digital Image Correlation to composite reinforcements testing. Composite Structures, 2017;160:670-688. DOI: 10.1016/j.compstruct.2016.10.096.
• De Santis S., Napoli A., de Felice G., Realfonzo R. Strengthening of structures with Steel Reinforced Polymers: A state-of-the-art review. Composites Part B: Engineering, 2016;104:87-110. DOI: 10.1016/j.compositesb.2016.08.025.
• Napoli A., de Felice G., De Santis S., Realfonzo R. Bond behaviour of Steel Reinforced Polymer strengthening systems. Composite Structures 2016;152:499-515. DOI: 10.1016/j.compstruct.2016.05.052.
• de Felice G., Aiello M.A., Bellini A., Ceroni F., De Santis S., Garbin E., Leone M., Lignola G.P., Malena M., Mazzotti C., Panizza M., Valluzzi M.R. Experimental characterization of composite-to-brick masonry shear bond. Materials and Structures, 2016;49(7):2581-2596. DOI: 10.1617/s11527-015-0669-4.
• Kwiecień A., de Felice G., Oliveira D.V., Zając B., Bellini A., De Santis S., Ghiassi B., Lignola G.P., Lourenço P.B., Mazzotti C., Prota A. Repair of composite-to-masonry bond using flexible matrix. Materials and Structures, 2016;49(7):2563-2580. DOI: 10.1617/s11527-015-0668-5.
• De Santis S., de Felice G. Steel reinforced grout systems for the strengthening of masonry structures. Composite Structures, 2015;134:533-548. DOI: 10.1016/j.compstruct.2015.08.094.
• Ascione, L., de Felice, G., De Santis S. A qualification method for externally bonded Fibre Reinforced Cementitious Matrix (FRCM) strengthening systems. Composites Part B: Engineering, 2015;78:497-506. DOI: 10.1016/j.compositesb.2015.03.079.
• De Santis S., de Felice G. Tensile behaviour of mortar-based composites for externally bonded reinforcement systems. Composites Part B: Engineering, 2015;68:401-413. DOI: 10.1016/j.compositesb.2014.09.011.
• de Felice G., De Santis S., Garmendia L., Ghiassi B., Larrinaga P., Lourenço P.B., Oliveira D.V., Paolacci F., Papanicolaou C.G. Mortar-based systems for externally bonded strengthening of masonry. Materials and Structures, 2014;47(12):2021-2037. DOI: 10.1617/s11527-014-0360-1.

• De Santis S, Hadad HA, De Caso y Basalo FJ, de Felice G, Nanni A. Acceptance Criteria for Tensile Characterization of Fabric Reinforced Cementitious Matrix (FRCM) Systems for Concrete and Masonry Repair. Journal of Composites for Construction. To appear.

Description

Textile Reinforced Mortar (TRM) composites are an effective, compatible and cost-efficient solution for repairing and strengthening existing structures. Recent research studies provided fundamental information on their tensile and bond properties as well as on the behaviour of retrofitted structural members. At the same time, important industrial developments made many systems available for applications in the field.

A Round Robin Test (RRT) was organized by the Rilem TC 250-CSM (Composites for the Sustainable Strengthening of Masonry) and Assocompositi (Italian Industry Association for Composite Materials) for the characterization of TRM composites. This initiative aimed at (i) collecting a wide experimental dataset, (ii) improving the knowledge on the mechanical behaviour of TRM systems, (iii) deriving information on the repeatability/variability of results (and on the causes of variability), and (iv) developing standardized methodologies for direct tensile tests and shear bond tests.

Nineteen research institution were involved, from 6 European Countries (France, Germany, Greece, Italy, Poland, Portugal and Slovenia). A total of 28 TRM systems were investigated, supplied by 11 industrial partners (ten of which were Italian and one was Greek). In order to validate test results and derive information on the incidence of experimental setups, at least two institutions tested each system (but reliable results on aramid systems were available only from one institution). The overall investigation included 68 test series, each of which comprised five direct tensile tests and five shear bond tests (with the only exception of two of them on TRM systems with glass textiles).

The Structures Research Group led this activity, starting from the design of the experimental study, the development of testing protocols, and the collection of test results.

List of scientific institutions and laboratories involved in the RRT

• University of Aachen, Germany
• CertiMaC, Italy
• Cracow University of Technology, Poland
• Milan University of Technology, Italy
• University of Minho, Portugal
• University of Bologna, Italy
• University of Chieti-Pescara, Italy
• Uni E-campus, Italy
• University of Firenze, Italy
• University of Lyon 1, France
• University of Naples, Italy
• University of Perugia, Italy
• University of Padova, Italy
• Roma Tre University, Italy
• University of Salento, Italy
• University of Sannio, Italy
• University of Trieste, Italy
• University of Patras, Greece
• University of Ljubljana, Slovenia

List of industrial partners and suppliers involved in the RRT

• Ardea Progetti srl, Italy
• BASF SpA, Italy
• Fibrenet srl, Italy
• Fyfe Co LCC, Greece
• G&P Intech srl, Italy
• Kerakoll SpA, Italy
• Mapei SpA, Italy
• Ruredil SpA, Italy
• Sacen srl, Italy
• Sika SpA, Italy
• TCS Calce srl, Italy

SanMarco-Terreal srl, Italy, provided the clay bricks to manufacture the brickwork prisms used as substrates in shear bond tests.

Key publications on this topic

• de Felice G, Aiello MA, Caggegi C, Ceroni F, De Santis S, Garbin E, Gattesco N, Hojdys Ł, Krajewski P, Kwiecień A, Leone M, Lignola GP, Mazzotti C, Oliveira D, Papanicolaou C, Poggi C, Triantafillou T, Valluzzi MR, Viskovic A. Recommendation of RILEM TC 250-CSM: Test method for Textile Reinforced Mortar to substrate bond characterization. Materials and Structures 2018;51:95. DOI: 10.1617/s11527-018-1216-x.
• Caggegi C, Carozzi FG, De Santis S, Fabbrocino F, Focacci F, Hojdys L, Lanoye E, Zuccarino L. Experimental analysis on tensile and bond properties of PBO and Aramid fabric reinforced cementitious matrix for strengthening masonry structures. Compos Part B-Eng 2017;127:175-195. DOI: 10.1016/j.compositesb.2017.05.048.
• Carozzi FG, Bellini A, D’Antino T, de Felice G, Focacci F, Hojdys L, Laghi L, Lanoye E, Micelli F, Panizza M, Poggi C. Experimental investigation of tensile and bond properties of Carbon-FRCM composites for strengthening masonry elements. Compos Part B-Eng. DOI: 10.1016/j.compositesb.2017.06.018.
• De Santis S, Carozzi FG, de Felice G, Poggi C. Test methods for Textile Reinforced Mortar systems. Compos Part B-Eng 2017;127:121-132. DOI: 10.1016/j.compositesb.2017.03.016.
• De Santis S, Ceroni F, de Felice G, Fagone M, Ghiassi B, Kwiecień A, Lignola GP, Morganti M, Santandrea M, Valluzzi MR, Viskovic A. Round Robin Test on tensile and bond behaviour of Steel Reinforced Grout systems. Compos Part B-Eng 2017;127:100-120. DOI: 10.1016/j.compositesb.2017.03.052.
• Leone M, Aiello MA, Balsamo A, Carozzi FG, Ceroni F, Corradi M, Gams M, Garbin E, Gattesco N, Krajewski P, Mazzoti C, Oliveira DV, Papanicolaou CG, Ranocchiai G,, Roscini F, Saenger D. Glass fabric reinforced cementitious matrix: Tensile properties and bond performance on masonry substrate. Compos Part B-Eng 2017;127:196-214. DOI: 10.​1016/​j.​compositesb.​2017.​06.​028.
• Lignola GP, Caggegi C, Ceroni F, De Santis S, Krajewski P, Lourenço PB, Morganti M, Papanicolaou C, Pellegrino C, Prota A, Zuccarino L. Performance assessment of basalt FRCM for retrofit applications on masonry. Compos Part B-Eng 2017;128:1-18. DOI: 10.1016/j.compositesb.2017.05.003.

It is mandatory that Fibre Reinforced Polymer (FRP) and Steel Reinforced Polymer (SRP) composites, like all construction materials, are qualified in order for them to be included in the design and accepted in the construction site. The Guidelines “Linea Guida per la identificazione, la qualificazione ed il controllo di accettazione di compositi fibrorinforzati a matrice polimerica (FRP) da utilizzarsi per il consolidamento strutturale di costruzioni esistenti.” issued by the Servizio Tecnico Centrale (STC) of the Consiglio Superiore dei Lavori Pubblici (CSLLPP) provides instructions on the process for the qualification of FRPs, which includes documentation and experimental tests.
The Structures Research Group carried out the experimental tests required for the qualification of FRP and SRP composites produced and supplied by Italian industries. The activity included the manucafturing of the specimens (prismatic coupons), their artificial aging for durability tests, the execution of the tensile tests, and the preparation of the official test reports. Technical support was also provided to industrial partners during the process of verification by the Servizio Tecnico Centrale (STC).
The following artificial aging processes were performed in a climatic chamber with temperature and relatie humidity control:

• Immersion in saline solution (substitute ocean water prepared in accordance with ATSM D1141); specimens stored in tanks at 23°C;
• Immersion in alkaline solution (pH>12) of calcium carbonate; specimens stored in tanks at 23°C);
• Exposure to humidity, consisting in 38°C and 98% relative humidity (R.H.)
• Exposure to freeze-thaw cycles, consisting in one week of pre-curing at 38°C and 98% R.H., followed by 20 cycles of 4 hours at -18°C and 12 hours at 38°C and 98% R.H.

The Experimental Laboratory is recognized as Official Laboratory in accordance with art. 20 of the Law 1086/71.