Textile Reinforced Concrete: Design Methodology and Novel Reinforcement

Fibre reinforcement has been used to reinforce concrete members for decades. It has combined well with concrete to help control cracking and increase toughness and other properties such as corrosion resistance. The use of traditional fibre reinforcement has led to the development of a new material called textile reinforcement (multifilament continuous fibre) which can also be used as the main reinforcement instead of steel reinforcement. This study experimentally investigates concrete beams reinforced only with carbon textile material (TRC beams). The tensile strength of textile reinforcement and pull out strength of TRC were measured. Four-point bending tests were performed on 76 beams (small and large scale beams). Several parameters such as volume fraction and reinforcement layout were studied in order to investigate their effect on TRC beam behaviour. The results showed that with the correct layout and geometry of textile reinforcement, these reinforced concrete beams, providing they had sufficient cover thickness, would perform well. Also, the results confirmed that the bond between the concrete and textile reinforcement plays a vital role in TRC beam performance. The behaviour of the TRC beams was compared with that of the steel reinforced concrete (SRC) beams; a major advantage of the TRC beam was the reduced crack widths. This study finishes by proposing a design methodology for TRC beams. Guidance covers flexural design, predictions for moment-curvature, and predictions for crack width of TRC beams

Behaviour of Textile-Reinforced Concrete Beams versus Steel-Reinforced Concrete Beams

There has been a rising interest in utilising textile reinforcement such as carbon tows in constructing concrete components to enhance the performance of conventional reinforced concrete. Textile-reinforced concrete (TRC) has been used as a construction material mostly as primary reinforcement. However, the structural performance of TRC members has not been investigated in depth. Therefore, to better understand TRC beams’ behaviour under bending load, a widespread experimental investigation was conducted. The results of tensile stress-strain, load-deflection, moment-curvature, and tension stiffening behaviours of TRC beams were associated with conventional steel-reinforced concrete (SRC) beams. In this study, the four-point bending and tensile strength tests were performed. The results revealed that, unlike the stress-strain behaviour observed in steel, textile reinforcement does not exhibit yielding strain. The flexural behaviour of TRC beams shows no similarity to that of SRC beams at postcracking formation. Besides, the moment capacity and tension stiffening of TRC beams were found 56% and 7 times higher than those of SRC beams, respectively. Therefore, in light of these results, it can be said that TRC beams behaviour differs from that of SRC beams

Textile-Reinforced Concrete Versus Steel-Reinforced Concrete in Flexural Performance of Full-Scale Concrete Beams

The effectiveness of textile-reinforced concrete (TRC) and steel-reinforced concrete (SRC) in the flexural performance of rectangular concrete beams was investigated in this study. To better understand TRC behaviour, large-scale concrete beams of 120 × 200 × 2600 mm were tested and analysed in this work. Cover thickness, anchoring, and various layouts were all taken into consideration to assess the performance of beams. In addition, bi-axial and uni-axial TRC beams and SRC beams were classified according to the sort and arrangement of reinforcements. The findings showed that anchoring the textiles at both ends enhanced load resistance and prevented sliding. The ultimate load of the tow type of textile reinforcement was higher, attributed to the increased bond. Variations in cover thickness also change the ultimate load and deflection, according to the findings. Consequently, in this investigation, the ideal cover thickness was determined to be 30 mm. Furthermore, for the similar area of reinforcements, the ultimate load of TRC beams was noted up to 56% higher than that of the SRC control beam, while the deflection was roughly 37% lower

Flexural Performance of Small-Scale Textile-Reinforced Concrete Beams

Textile-reinforced concrete (TRC) as a novel high-performance composite material can be used as a strengthening material and component bearing load alone. The flexural performance of TRC beams strengthened with textile reinforcement such as carbon tows was experimentally examined and associated with those of steel-reinforced concrete (SRC) beams. Through four-point bending tests, this research explores the effects of textile layers and dosages of short textile fibre on the flexural strength of concrete beams. A total of 64 prism samples of size 100 mm × 100 mm × 500 mm were made, flexure-strengthened, and tested to evaluate various characteristics and the efficiency of TRC versus SRC beams. TRC beams performed exceptionally well as supporting material in enhancing concrete’s flexural capacity; in addition, TRC’s average ultimate load effectiveness was up to 56% than that of SRC specimens. Furthermore, the maximum deflection was about 37% lesser than SRC beams. The results showed that by increasing the number of layers, the TRC’s effectiveness was significantly increased, and the failure mode became more ductile

Evaluation of the Effect of Recycled Polypropylene as Fine Aggregate Replacement on the Strength Performance and Chloride Penetration of Mortars

Nowadays, the re-use and recycling of industrial wastes to reduce the environmental impact and landfill problems are the main concerns of researchers. Plastics are one of the main waste materials worldwide, with considerable impacts on health and environmental conditions. Recycling plastic wastes in the concrete industry is one of the adopted ways to reduce such impact and increase the economic recyclability of plastics. In this study, the utilization of recycled polypropylene (rPP) as a fine aggregate in the preparation of cement mortars was evaluated. The river sand was replaced with 10, 20, 30, 40, and 50%, volumes of rPP. The results showed that the inclusion of rPP reduced the mortar’s workability and fresh density. Fresh density dropped from 11% to 35% as the rPP content increased. Furthermore, the compressive strength at early and late age was significantly influenced by the rPP content. At 28 days of curing age, the results showed that the inclusion of 50% of rPP in the mortar matrix led to a drop in the compression strength from 40 MPa to 10 MPa. A similar trend of results was obtained for the flexural (from 8.3 MPa to 2.9 MPa) and tensile strengths (from 3.4 MPa to 1.21 MPa). The chloride ion penetration went through a maximum of 5000 Coulombs between 10% and 50 % of rPP. Therefore, it can be concluded that the use of 10% of rPP as a river sand replacement can achieve acceptable strength (25 MPa) for several applications in the construction industry

Enhanced performance of concrete composites comprising waste metalised polypropylene fibres exposed to aggressive environments

The utilisation of waste plastic and polymeric-based materials remains a significant option for clean production, waste minimisation, preserving the depletion of natural resources and decreasing the emission of greenhouse gases, thereby contributing to a green environment. This study aims to investigate the resistance of concrete composites reinforced with waste metalised plastic (WMP) fibres to sulphate and acid attacks. The main test variables include visual inspection, mass loss, and residual strength, as well as the microstructural analysis of specimens exposed to aggressive environments. Two sets of concrete mixes with 100% ordinary Portland cement (OPC) and those with 20% palm oil fuel ash (POFA) were made and reinforced with WMP fibres at volume fractions of 0–1.25%. The results revealed that the addition of WMP fibres decreased the workability and water-cured compressive strength of concrete mixes. The outcomes of the study suggest that the rate of sulphate and acid attacks, in terms of mass losses, was controlled significantly by adding WMP fibres and POFA. The mutual effect of WMP fibre and POFA was detected in the improvement in the concrete’s resistance to sulphate and acid attacks by the reduction in crack formation, spalling, and strength losses. Microstructural analysis conducted on the test specimens elucidates the potential use of POFA in improving the performance of concrete in aggressive environments

Performance evaluation of novel prepacked aggregate concrete reinforced with waste polypropylene fibers at elevated temperatures

The prepacked aggregates fiber-reinforced concrete (PAFRC) is an innovative type of concrete composites that recently has gained popularity and pulled the attention of researchers worldwide. The preparation of PAFRC, which is a novel developed concrete, comprises the placing and packing of coarse aggregates with different sizes and short fibers in a formwork, and the spaces between the aggregates are then filled through the injection of cement grout with high flowability. Fire is one of the most disparaging reasons for the collapse of the concrete structures. Therefore, this study aims to investigate the influence of waste polypropylene (PP) fibers on the mechanical and microstructural properties of PAFRC at elevated temperatures of up to 600 °C. Five mixes comprising fiber volume fractions from 0 to 1.0% with a length of 30 mm were cast by gravity technique. Another five mixtures with the same fiber volume fractions were cast using a pump to inject the grout into the formwork. Additionally, palm oil fuel ash (POFA) was used at the substitution level of 20%. The fire resistance of the PAFRC specimens was then measured in terms of mass loss, ultrasonic pulse velocity, compressive and tensile strengths. The role of fibers was inspected through the analysis of the microstructure in terms of scanning electron microscopy. Besides, the experimental outcomes were statistically analyzed. The findings revealed that the waste PP fiber reinforcement in combination with POFA in PAFRC mixes turned out to deliver high resistance against elevated temperatures by the reduction in spalling and losses in the mass of specimens. The positive interaction between fibers and POFA subsequently led to the higher compressive and tensile strength values of PAFRC specimens at high temperatures. Moreover, the outcomes indicated that PP fibers and POFA are promising materials for the production of PAFRC with satisfactory fire resistance

The impact resistance and deformation performance of novel pre-packed aggregate concrete reinforced with waste polypropylene fibres

Pre-packed aggregate fibre-reinforced concrete (PAFRC) is an innovative type of concrete composite using a mixture of coarse aggregates and fibres which are pre-mixed and pre-placed in the formwork. A flowable grout is then injected into the cavities between the aggregate mass. This study develops the concept of a new PAFRC, which is reinforced with polypropylene (PP) waste carpet fibres, investigating its mechanical properties and impact resistance under drop weight impact load. Palm oil fuel ash (POFA) is used as a partial cement replacement, with a replacement level of 20%. The compressive strength, impact resistance, energy absorption, long-term drying shrinkage, and microstructural analysis of PAFRC are explored. Two methods of grout injection are used—namely, gravity and pumping methods. For each method, six PAFRC batches containing 0–1.25% fibres (with a length of 30 mm) were cast. The findings of the study reveal that, by adding waste PP fibre, the compressive strength of PAFRC specimens decreased. However, with longer curing periods, the compressive strength enhanced due to the pozzolanic activity of POFA. The combination of fibres and POFA in PAFRC mixtures leads to the higher impact strength energy absorption and improved ductility of the concrete. Furthermore, drying shrinkage was reduced by about 28.6% for the pumping method PAFRC mix containing 0.75% fibres. Due to the unique production method of PAFRC and high impact resistance and energy absorption, it can be used in many pioneering applications

Effect of waste glass bottles-derived nanopowder as slag replacement on mortars with alkali activation: durability characteristics

Various alkali-activated binders (AABs) incorporated with different industrial wastes emerged as useful environmental affable materials in the construction sectors as alternative to the traditional cement due to their lower CO2 emission and landfill problems mitigation. The sustainability of concretes is the major global concern in the construction sectors. In this view, the effects of waste glass bottles-derived nanopowder (WGBNP) on the durability characteristics of five batches of alkali-activated mortars (AAMs) with the inclusion of fly ash (FA) and ground blast furnace slag (GBFS) were evaluated. These AAMs were designed via the replacement of GBFS at various WGBNP contents (0%, 5%, 10%, 15% and 20%). Analytical tests were performed to determine the mortars compressive strength, porosity, drying shrinkage, and resistance to aggressive environments. Microstructures characteristics were assessed using XRD measurements. Replacement of GBFS by WGBNP was found to remarkably improve the durability traits of the produced AAMs, solving the environmental and landfill problems. The results indicated that the inclusion of 5% of WGBNP in alkali-activated matrix led to the reduction of porosity and enhancement of the strength and durability performance. Additionally, the replacement of GBFS by WGBNP was found to improve the durability performance in terms of reduced drying shrinkage and increased resistance to sulphuric acid, wearing, and freeze-thaw cycles. The obtained AAMs were demonstrated to be environmentally beneficial regarding the lowering of global warming

Drying shrinkage and creep properties of prepacked aggregate concrete reinforced with waste polypropylene fibers

Prepacked aggregate concrete (PAC) is a particular form of concrete that is manufactured by placing and packing aggregates with different sizes in a formwork, and the spaces between the aggregates are then filled through the injection of cement grout with high flowability. This study proposed the prepacked aggregates fiber-reinforced concrete (PAFRC), which is a newly developed concrete, with a unique combination of coarse aggregate and short polypropylene (PP) fiber that is premixed and placed in the formworks. This study presents the outcomes of an investigational work that addresses creep and drying shrinkage performance in addition to the strength development of PAFRC specimens. In addition, palm oil fuel ash (POFA) was used at the substitution level of 20%. Six mixes comprising fiber volume fractions of 0–1.25% with a length of 30 mm were cast by gravity technique. Another six mixtures with the same fiber volume fractions were cast using a pump to inject the grout into the formwork. The experimental outcomes exposed that utilization of waste PP fibers and POFA improved the compressive strength of PAFRC mixes. The drying shrinkage and creep of PAFRC mixes reduced significantly with the addition of waste PP fibers. Moreover, due to the lower drying shrinkage and creep, as well as the unique production technique, PAFRC could be used for several innovative applications in construction