Research database

With the construction industry being responsible for almost half of the global emissions, the sustainable reuse of the existing buildings is considered the most relevant step to be taken toward low carbon targets. The Italian built environment comprises a vast number of ageing historic structures, whose repair still involves a considerable usage of raw materials and energy-intensive processes. In this view, deploying sustainable and innovative procedures for structural rehabilitation is an objective of relevant national interest. REHARZE will focus on the structural use of natural reinforcing fibres in combination with inorganic matrices to create a ‘fully-green’ composite retrofitting system – known as Natural Textile Reinforced Mortar (NTRM) - particularly suitable for masonry structures. To date, experimental and analytical studies focusing on NTRM are limited, causing further industry investments into non-renewable fibrous materials and matrices. The goals of REHARZE are a) to mechanically characterise renewable plant-based NTRM composites and validate their suitability as strengthening systems for masonry buildings; b) to optimise the material architecture as a function of the components, and c) to set design rules for promoting their deployment in the market. Experimental and numerical-theoretical studies entail the participation of three Research Units (RUs): University of Salerno (UniSa), Polytechnic of Torino (UniTo) and Polytechnic of Bari (PoliBa). The experimental activity will be performed by PoliTo and UniSa RUs. PoliTo will lead the mechanical characterisation of NTRM composites. Tensile tests will be performed on both single threads and dry fabric samples as well as on NRTM composites coupons. UniSa will lead the experimental analysis of the bond behaviour by performing direct single-lap shear tests on NTRM strengthened masonry prisms. The experimental tests will be aimed at exploring the influences of several geometrical and mechanical properties such as fibre type, strip width, number of layers number and thickness of the matrix. The system performance will be assessed by analysing the constitutive behaviour, the peak load, the failure modes, the reinforcement efficiency rate, and the shear stress-slip interface constitutive law. The numerical-theoretical activity will be informed by the results of the experimental tests and analysis, that will serve to validate and calibrate numerical models. PoliBa will lead the overarching goal to provide a key contribution to the industrial deployment of efficient natural fibre-based reinforcing grids. The synergic collaboration among the RUs will lead to the development of a) a detailed computational approach for the identification of key factors of the NTRM behaviour, b) a Genetic Algorithm informed routine for the topological optimisation of the composite as a function of the components, c) sound analytical formulae for the design prediction of the NTRM performance.