Sustainability, Durability, and Mechanical Characterization of a New Recycled Textile-Reinforced Strain-Hardening Cementitious Composite for Building Applications

Cementitious materials have one of the highest compressive strength-to-weight ratios compared to other construction materials. Nonetheless, both tensile strength capacity and toughness result to be an order of magnitude less respect to the former, which thereby leads to cracking under tensile stresses caused by service loads. This lack of tensile strength capacity of the material leads to cracking and fragile failure in case the material is insufficiently reinforced. Within this context, fibers can be used in cementitious matrices aiming at enhancing the toughness, energy absorption capacity, post-cracking behavior as well as flexural and tensile strength. Although during the past decades, various types of fibers such as asbestos, steel, glass, and polymeric have been tested in brittle matrices, there have been some disadvantages such as detrimental health effects, high cost, and specifically, substantial environmental footprint. Likewise, based on the statistics, the construction sector is responsible for about 40% of the European Union's total final energy consumption, 35% of its total CO2 emissions, and 45% of waste generation. That is why significant efforts should be devoted to applying the ‘3Rs’ concept of reducing, reusing, and recycling in the building sector and material fabrication. On the other hand, the textile leftover is one of the predominant waste resources worldwide while only less than 20% is being recycled. The textile industry produces textile wastes (TW) from the primary stages of garment production (pre-consumer waste such as fiber, yarn, and fabric) to the end of its useful life (post-consumer waste: discarded clothes). Thus, the reuse of this textile waste in construction is becoming interesting and convenient due to the shortage of natural mineral resources and increasing waste disposal costs. Recently, sustainable fibers produced from renewable, biodegradable, waste, recycled, available, and low-cost resources becoming a focal point. In this sense, vegetable and cellulosic fibers have already been used as reinforcement in cementitious materials for low- to medium-performance structural applications. TW fiber could be another sustainable alternative for reinforcement in cementitious composites. In view of the abovementioned, this research comprehensively verifies, by means of physical, mechanical, and durability-based material characterization tests, the possibility of incorporation of short TW fiber as well as the nonwoven TW fabric in the cementitious composites as internal reinforcement to produce a sustainable, ductile, and durable composite to be used in building applications. In this regard, several experimental tests were carried out on different mix design samples to characterize the mechanical, microstructural, durability, thermal, acoustic, fire, and shrinkage properties. The results have shown that the recycled TW fiber, especially in the form of nonwoven fabric, could be a technically feasible, sustainable, and durable reinforcement to be used in the cementitious mortar for low to medium-performance structural applications (e.g., façade panels, roofing, raised floors, and masonry structures). Further, the sustainability of the optimum composite as a façade cladding panel (as an example of one projected application) was assessed through the MIVES, a new comprehensive and integrated Multi-Criteria Decision-Making method that embraces the three pillars of sustainability: economic, environmental, and social. Future works on this kind of fiber-reinforced cementitious mortar could be to develop a numerical model simulation or produce a 3D concrete printing (3DCP) prototype by employing additive manufacturing technology.