Papers by Keyword: Polypropylene Fiber

Abstract: The construction industry plays a vital role in the economic development and overall progress of any country. Construction activities have significant impact on the economy, but their environmental consequences cannot be overlooked. The excessive use of construction materials particularly cement and steel, which are among the most commonly used construction materials, has become a major environmental concern, as these materials are also key sources of carbon emissions. Moreover, the raw materials required for the preparation of cement and Steel are also depleting at a rapid pace. Therefore, it is necessary to conduct research studies to find new alternative materials which can reduce the consumption of cement and steel in the concrete. Fly ash can be used as binding agent in concrete as it has good cementation properties and is abundantly available. To enhance the mechanical performance of geopolymer concrete (GPC), polypropylene fibers (PPFs) were incorporated in varying ratios (0.5% to 1.5% by volume). The samples were prepared to test the mechanical and durability properties of the concrete. Compressive Strength, Flexural Strength, and Split Tensile Strength test was carried out to conclude the mechanical properties of the geopolymer concrete against different percentages of polypropylene Fiber. Acid attack and rapid chloride permeability tests were conducted out to evaluate the durability of the concrete. The research findings depicted that the greatest compressive strength and split tensile strength are obtained at 1% PPFs GPC. The least amount of chloride penetration was demonstrated by GPC, at 1.5% PPFs.

Abstract: The construction industry significantly contributes to global CO₂ emissions and environmental impact, mainly due to concrete usage, which consumes vast resources and energy while emitting CO₂. Researchers are exploring alternatives such as geopolymer concrete (GPC), formed without traditional cement but through alkaline activation of industrial by-products like fly ash, ground granulated blast furnace slag, bentonite, and metakaolin clay. This study evaluates the effects of incorporating bentonite and polypropylene (PP) fibers on the workability and strength properties of GPC based on slag. Bentonite substituted 10% of slag, and PP fibers were added at varying ratios (0.5%, 0.75%, and 1%). Both untreated and heat-treated bentonite, heated up to 200°C, were used. Workability was assessed using a slump cone, while mechanical properties, including compressive, split-tensile, and flexural strength, were analyzed. Notably, heat-treated bentonite and PP fibers exhibited significant enhancement in the mechanical properties of the GPC mixes.

Abstract: The feasibility of determining the extent of damage in fibered concrete after being subjected to high temperatures, using non-destructive methods was investigated. The study was conducted on four concrete mixtures with different fiber types. The specimens underwent a curing process at 23 °C before being exposed to different high temperatures of 400 °C, 600 °C, and 800 °C. After cooling to ambient temperature, various non-destructive tests including ultrasonic pulse velocity testing (UPV), the resonance frequency test (RF), the dynamic modulus of elasticity (Ed), the thermal conductivity test (λ), and Schmid Rebound Hammer (SRH), were performed. To evaluate the sensitivity of non-destructive techniques to assess the damage of fiber-reinforced concrete, the Lemaitre coefficient was used as a variable to describe the extent of the damage. The results indicated that the highest damage levels were obtained through the modulus of elasticity technique regardless of the type of concrete mixture or temperature exposure. There was also a potential agreement found between thermal and ultrasonic methods in evaluating the thermal degradation of concrete.

Abstract: This article shows the results of the modulus of rupture test for concrete specimens added with PET fibers and also with polypropylene, with the objective of giving a second use to this waste through recycling, and its incorporation into concrete to improve its mechanical properties. The samples were tested with different fiber contents, and the results showed an increase in the modulus of rupture at 90 days with respect to a normal sample (1-3%). Specimens with PET and polypropylene fibers had a poor performance (<18%).

Abstract: Cellular concrete (known as foamed concrete) is a lightweight building material with low densities ranging from 900 kg/m³ to 1900 kg/m³, which can have potential applications in civil engineering practices. However, it is very weak in withstanding tensile loads which leads to cracks during shrinkage in the drying stage. Therefore, six different groups of cellular concrete are prepared for a possible application in grouting underneath the foundations to achieve a minimum compressive strength of 2000 psi (13.79 MPa) as per ASTM C476, and for soil nail grout with a minimum compressive strength of 3000 psi (20.86 MPa) as per ASTM C109 at 28 days. Furthermore, these mixtures are undergoing laboratory testing for pushout (using steel cylinders with varied diamters and thickneses) and pullout tests as the subsequent part of this project. All groups contain 0.34 water-to-cement ratio, same size and amounts of sands and superplasticizer (SP). The first group included four control mixes without bentonite and polypropylene fiber (PPF) additives with varied foam content (C1-F1,F2,F3,F4). The remaining groups consist of 17 different mixes blended with either one or both additives. The content effect of foam agent, bentonite clay, and PPF as additives on the density and compressive and flexural strengths of cellular concrete are investigated in this study. The results revealed that the introduction of bentonite and/or PPF in cellular concrete mixtures increased the density and strength. The results revealed that low dry densities (less than 1900 kg/m³) of blended cellular concrete mixtures can reach high compressive strength of 24.37 MPa with 4.74 MPa flexural strength that make them feasible for geotechnical and structural engineering applications.

Abstract: The present work investigates the use of an alumino-silicate material, the pyrophyllite as cement substitution, synthetic polypropylene fibers and binder to create an unusual ultra-performance fiber concrete; new composite, which offers a wide field of possible use in construction industry. Effect of pyrophyllite on the physical-mechanical properties is analyzed. One reference fiber concrete without pyrophyllite and three fiber concretes containing 10%, 20%, 30% of pyrophyllite were elaborated. Results show that the pyrophyllite affects the characteristics of the concrete. Indeed, in the hardened state, the density of fiber concrete decreased with pyrophyllite rate increasing. Moreover, the use of pyrophyllite slows down the hardening process of concrete, consequently producing at early ages, compressive, flexural and tensile strengths and elastic modulus of concretes approaching without exceeding those of the reference fiber concrete. The fiber concretes are also considered to be of good quality. It seems that the rate of 10 % of pyrophyllite generates the best physical-mechanical performances that approach those of the reference fiber concrete. The use of pyrophyllite as a cement substitution is beneficial since it can help to decrease the production of cement; the amount of CO₂ released and protects the environment.

Abstract: Currently, there is a steady increase in the production of reinforced concrete structures in factory and construction site conditions for various types of modern buildings with higher operational requirements for them. These structures are pre-calculated according to complex design schemes of loading which also leads to increased requirements for the materials used. One of the ways to solve a number of these problems is the use of fiber-reinforced concretes, but for this it is necessary to experimentally identify the deformation and strength characteristics of dispersed reinforced concretes and take it into account when calculating structures. A scientific team of the Institute of New Materials and Technologies of the Ural Federal University is engaged in solving of this research task, which will expand a number of construction opportunities while maintaining economic feasibility in the future.

Abstract: This investigation aims to improve some of the mechanical properties of concrete such as compressive strength, flexural strength, and modulus of elasticity, by using different percentages of polypropylene fibers, and also studying the durability of concrete for freeze-thaw cycles. the study shows a small increment in compressive strength due to adding fibers which were 28.3% compared with increment in flexural strength which was perfect (about 191%), modulus of elasticity also increased by adding fibers. The durability of concrete against freezing-thaw cycles for all mixes was studied. Fiber-reinforced concrete shows more durability against freezing-thawing cycles and less reduction in strength compared with reference mixes without fibers,21.5% reduction in strength for optimum polypropylene fiber concrete while the reduction in strength for normal concrete was found 54.2% in this study.

Abstract: Due to the elevating demand to replace the conventional cement concrete with any other building material, there has been a continuous effort to promote the properties of geopolymer concrete. The objective of this paper is to reduce the brittleness of geopolymer concrete. This research paper goes for exploring the impact of high and low young’s modulus fiber in geopolymer concrete made of M-sand. Mix proportion of various materials is based on the Rangan’s proposed Mix design. Geopolymer concrete used in this investigation is the Fly ash – Ground Granulated Blast Furnace Slag blend based. Concoction of NaOH solution and Na2SiO3 solution is used as the alkali solution. Sine 80 percent of the source material is flyash, the specimens are exposed to heat curing. Fresh property and hardened characteristics like workability, ductility factor, compressive, split tensile, flexural and impact strength are assessed in this study. Significant increase in the engineering properties is observed with respect to both the fibers. This work unveils lot of potential in the vicinity of Geopolymer concrete.

Abstract: This paper presents a study that aimed to assess the chloride penetration depth of recycled aggregate concrete (RAC) modified by using treated coarse recycled concrete aggregate (RCA), adding polyolefin (PO) or polypropylene (PP) fibre and comparing with normal concrete. The coupling effects of the treated RCA and fibres on the chloride penetration of RAC were analysed after two different curing regimes (i.e. normal and seawater) and tested at different curing ages (i.e. 90, 180 and 300 days). Results showed that the inclusion of treated coarse RCA can reduce porosity, thereby decreasing the chloride penetration of RAC. However, the coupling effects of treated coarse RCA and fibre, especially on the use of PO fibre, can enhance the results.