Flexible Adhesive in Composite-to-Brick Strengthening-Experimental and Numerical Study

Arkadiusz Kwiecień; Piotr Krajewski; Łukasz Hojdys; Marcin Tekieli; Marek Słoński

doi:10.3390/polym10040356

Flexible Adhesive in Composite-to-Brick Strengthening-Experimental and Numerical Study

Polymers (Basel). 2018 Mar 22;10(4):356. doi: 10.3390/polym10040356.

Authors

Arkadiusz Kwiecień¹, Piotr Krajewski², Łukasz Hojdys³, Marcin Tekieli⁴, Marek Słoński⁵

Affiliations

¹ Institute of Structural Mechanics, Cracow University of Technology, 31-155 Cracow, Poland. arkadiusz.kwiecien@pk.edu.pl.
² Institute of Building Materials and Structures, Cracow University of Technology, 31-155 Cracow, Poland. piotr.krajewski@pk.edu.pl.
³ Institute of Building Materials and Structures, Cracow University of Technology, 31-155 Cracow, Poland. lukasz.hojdys@pk.edu.pl.
⁴ Institute for Computational Civil Engineering, Cracow University of Technology, 31-155 Cracow, Poland. marcin.tekieli@l5.pk.edu.pl.
⁵ Institute for Computational Civil Engineering, Cracow University of Technology, 31-155 Cracow, Poland. marek.slonski@L5.pk.edu.pl.

Abstract

This paper investigates composite-to-brick strengthening systems with flexible adhesive made of polyurethane (Carbon Fibre Reinforced Polyurethane (CFRPU) and Steel Reinforced Polyurethane (SRPU)) and epoxy resin (Carbon Fibre Reinforced Polymer (CFRP) and Steel Reinforced Polymer (SRP). The specimens were tested in a single lap shear test (SLST). LVDT displacement transducers (LVDT ⁻ Linear Variable Differential Transformer) and digital image correlation method (DIC) based measurement systems were used to measure displacements and strains. The obtained results were applied in a numerical analysis of the 3D model of the SLST specimen, with flexible adhesives modeled as a hyper-elastic model. The DIC and LVDT based systems demonstrated a good correlation. Experimental and numerical analysis confirmed that composite-to-brick strengthening systems with flexible adhesives are more effective on brittle substrates than stiff ones, as they are able to reduce stress concentrations and more evenly distribute stress along the entire bonded length, thus having a higher load carrying capacity.

Keywords: CFRP; CFRPU; DIC measurements; SRP; SRPU; experimental tests; flexible adhesives; masonry; numerical analysis; shear bond tests; strengthening.