Constitutive Models for the Tensile Behaviour of TRM Materials: Literature Review and Experimental Verification.

Maria Concetta Oddo,Giovanni Minafò,Lidia La Mendola

doi:10.3390/ma14030700

Abstract

In recent years, the scientific community has focused its interest on innovative inorganic matrix composite materials, namely TRM (Textile Reinforced Mortar). This class of materials satisfies the need of retrofitting existing masonry buildings, by keeping the compatibility with the substrate. Different recent studies were addressed to improve the knowledge on their mechanical behaviour and some theoretical models were proposed for predicting the tensile response of TRM strips. However, this task is complex due to the heterogeneity of the constituent materials and the stress transfer mechanism developed between matrix and fabric through the interface in the cracked stage. This paper presents a state-of-the-art review on the existing constitutive models for the tensile behavior of TRM composites. Literature experimental results of tensile tests on TRM coupons are presented and compared with the most relevant analytical models proposed until now. Finally, a new experimental study is presented and its results are used to further verify the reliability of the literature expressions.

Highlights

In recent times, the technology of inorganic matrix composites, namely FRCM (FabricReinforced Cementitious Matrix) or Textile Reinforced Mortar (TRM) materials, has been used in numerous retrofitting and strengthening practical applications and is preferred to polymer-based composites FRPs (Fibre Reinforced Polymers), especially for masonry structures [1]
This paper shows a review of existing simplified analytical models for the tensile constitutive behaviour of TRM materials, supported by a new experimental investigation
This paper presented a review on the state of research for TRM tensile behavior, with particular reference to the analytical models available in the literature to predict the mechanical response: ACK, Simplified and Tension Stiffening Model

Summary

Introduction

The technology of inorganic matrix composites, namely FRCM (FabricReinforced Cementitious Matrix) or Textile Reinforced Mortar (TRM) materials, has been used in numerous retrofitting and strengthening practical applications and is preferred to polymer-based composites FRPs (Fibre Reinforced Polymers), especially for masonry structures [1]. The use of inorganic matrices allows TRM systems to include many advantages when applied to an existing masonry support, overcoming the drawbacks associated to the adoption of epoxy resins. Despite the growing spread of TRM materials, the modelling and characterization of the mechanical response of these innovative composites are still open issues, due to the inner mechanical complexity of the stress transfer mechanisms between fabric, matrix and support. For these reasons, several experimental studies were addressed to the mechanical characterization for the homologation and the acceptance of TRM composites, with particular reference to their tensile behaviour. Experimental outcomes have shown that many variables are involved in the tensile constitutive laws, in particular the nature of fabric, eventual treatment of the yarns, the test set-up employed, the amount and the geometry of the fabric and the grade of the mortar

Results

Discussion

Conclusion