# Sustainable Development of Concrete through Aggregates and Innovative Materials: A Review
## 3 Synthetic Fibers
### Textile Fibers and Reinforcements  
Textiles mixed in concrete are materials with appropriate mechanical properties that can reduce the density and costs of the concrete, helping in the reduction of the CO\({}_{2}\) emissions. These materials are sustainable solutions in structural reinforcement and structural reconditioning elements in civil engineering constructions [82; 83].  
[PERSON] et al. [82] compared the durability of textile reinforced concrete (TRC) using tensile and flexural loads after 14, 90 and 120 days. TRC specimens were prepared with two different proportions with 2 to 6 glass fiber layers. Based on the results, fibers were subjected to flexural strength without find differences within the microstructure. Slight fractures were observed on the specimens' surface. After 90 days, an increase in tensile and flexural strength were observed. In addition, a decrease in ductility was measured in the speeding process of the specimens' age.  
[PERSON] and [PERSON] [83] evaluated the tensile strength of high resistance textiles incorporated within inorganic matrixes. Six different fiber types were embedded in cement matrixes, including carbon, glass, basalt and steel cables. The 500 mm long fiber was subjected to a tensile strength test according to guidelines of ASTM D3039. The mechanical properties were characterized in the cementing matrix in 32 rectangular prisms. In these tensile strength tests, three failures were registered: a major crack near the specimen fastening, a major crack in the greatest fastening zone and a crack near the fastening with textile slipping within the matrix.  
[PERSON] et al. [84] developed relevant data about test methods for textile reinforced mortars. They employed textile reinforced mortar instead without epoxy resins to provide a better behavior under high temperatures and a quick and easy installation. In addition, it does not generate risks for the workers due to toxic volatile compounds. The tensile strength tests were carried out in prismatic specimens with a rectangular cross-section, which have one or more fiber layers embedded in the mortar matrix. The samples were curing at 28 days and their stress-strain behavior was characterized with three response stages (uncracked, fracture development and cracking).  
Textile reinforced concrete allows sustainable building material with good mechanical behavior for structural elements and architectural components. A potential application of TRC are the thin structural elements such as shell, laminar or folded components. In addition, TRC is suitable for prefabricated structural components. Due to its low thickness, TRC has low weight and can be transported and assembled on site. In addition, the TRC-based structural components can be used in demountable, modular and reusable systems [85].  
[PERSON] et al. [86] investigated the compressive behavior of TRC-confined masonry columns. In addition, they developed equations to estimate the compressive strength and ultimate strain of TRC-confined masonry columns considering the experimental data. The samples confined with the carbon-glass TRC improved the ductile performance in comparison with that of the basalt-glass TRC. The equations of [PERSON] et al. [86] to predict the compressive strength of TRC-confined masonry columns agreed well with the experimental results. However, the equations to calculate their ultimate strain presented a lower accuracy.  
Sustainable development continuously is growing within the construction industry. TRC represents an innovative material that increases mechanical properties of concrete. It has been a subject of research and models have been created regarding fiber incorporated to concrete to demonstrate its efficiency. For instance, Figure 9 depicts waste cotton fibers, obtained from blue-jeans, which were incorporated to polyester concrete [87].