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The aim of the work is to investigate structural behaviour of reinforced concrete (RF) beam retrofitted with basalt fibre (BF) fabric. The incorporation of BF showed enhancement in bending strength, to increase confinement and to repair damages caused by cracking. In the early decades, using BF for composite materials shaped BF as an excellent physical substance with necessary mechanical properties, highlighting the significant procedures ability.

Specimens were casted with U-wrapped BF and then evaluated based on flexural tests. In the test carried over for flexural fortifying assessment, BF reinforcements demonstrated a definitive quality improvement in the case of the subjected control sample; ultimately, the end impacts depend upon the applied test parameters. From the outcomes introduced in this comparison, for the double-wrapped sample, the modifications improved by 12% than that of the single-wrapped beam, which is identified to subsist for a better strengthening of new-age retrofitting designs.

The current research deals with the retrofitting of RC beam by conducting a comparative experiment on wrapping of BF (single or double BF wrapping) in improving the mechanical behavior of concrete.

It can be shown from the experimental results that increasing the number of layers has significant effect on basalt strengthened beams.

Building elements that are damaged by fire are often strengthened by fiber wrapping techniques. Self-compacting concrete (SCC) is an advanced building material that is widely used in construction due to its ability to flow and pass through congested reinforcement and fill the required areas easily without compaction. The aim of the research work is to examine the flexural behavior of SCC subjected to elevated temperature. This research work examines the effect of natural air cooling (AC) and water cooling (WC) on flexural behavior of M20, M30, M40 and M50 grade fire-affected retro-fitted SCC. The results of the investigation will enable the designers to choose the appropriate repair technique for improving the service life of structures.

In this study, an attempt has been made to evaluate the flexural behavior of fire exposed reinforced SCC beams retrofitted with laminates of carbon fiber reinforced polymer (CFRP), basalt fiber reinforced polymer (BFRP) and glass fiber reinforced polymer (GFRP). Beam specimens were cast with M20, M30, M40 and M50 grades of SCC and heated to 925ºC using an electrical furnace for 60 min duration following ISO 834 standard fire curve. The heated SCC beams were cooled by either natural air or water spraying.

The reduction in the ultimate load carrying capacity of heated beams was about 42% and 55% for M50 grade specimens that were cooled by air and water, respectively, in comparison with the reference specimens. The increase in the ultimate load was 54%, 38% and 27% for the specimens retrofitted with CFRP, BFRP and GFRP, respectively, compared with the fire-affected specimens cooled by natural air. Water-cooled specimens had shown higher level of damage than the air-cooled specimens. The specimens wrapped with carbon fiber could able to improve the flexural strength than basalt and glass fiber wrapping.

SCC, being a high performance concrete, is essential to evaluate the performance under fire conditions. This research work provides the flexural behavior and physical characteristics of SCC subjected to elevated temperature as per ISO rate of heating. In addition attempt has been made to enhance the flexural strength of fire-exposed SCC with wrapping using different fibers. The experimental data will enable the engineers to choose the appropriate material for retrofitting.

In the early days of pipe protection, it was thought that any coating reinforced with any type of wrapping could not fail to extend the life of a buried pipeline system. Today, as a result of experience accumulated by many users in different parts of the world, we know that only the careful selection of both pipe coatings and reinforcing inner and outer wraps can be relied on to protect a buried pipeline system effectively. This article considers the functions of a pipeline coating, and the materials and coating systems which best carry out these functions.

The purpose of this study was to produce yarns from three different spinning techniques, i.e.Murata Vortex Spinning (MVS) ring spinning and rotor spinning. Those yarns were then used to produce fabrics. Then, the effect of silicone softener on tactile comfort of fabric was investigated.

Three different yarns, i.e. Ring, Rotor and MVS yarns, were used to make fabrics using CCI sample loom which were then subjected to post treatments like desizing, scouring and bleaching. After the completion of the dyeing process, silicone-based softener was used to improve the hand feel of fabrics. The structures of three yarns were evaluated using Scanning electron microscopy. The fabrics were evaluated against compression, bending and surface properties using Kawabata evaluation system.

The fabric made of MVS yarn depicted more geometrical roughness, coefficient of friction and bending rigidity but less compressibility as compared to fabrics made with other yarns. It was observed that softener concentration has a direct relationship with thickness and bending rigidity of the fabric, and inverse relationship with coefficient of friction and geometrical roughness of the fabric.

MVS yarn has some superior properties over rotor and ring spun yarn like high production rates, high resistance to pilling, clear appearance and stability against deformation but has disadvantage that it has less compressibility. Therefore, softener is applied on the fabric, to address this issue, so that it could also be used for apparels application.

The limited strength of polylactic acid (PLA) hinders its extensive engineering applications. This paper aims to enhance its strength and realize diverse applications.

Here, the continuous fiber reinforced PLA composites are fabricated by a customized fused filament fabrication three-dimensional printer. Uniaxial tensile and three-point flexural tests have been conducted to analyze the reinforcement effect of the proposed composites. To unveil the adhering mechanism of optic fiber (OF) and PLA, post failure analysis including the micro imaging and morphology have been performed. The underlying mechanism is that the axial tensile strength of the OF and the interfacial adhesion between PLA and OF compete to enhance the mechanical properties of the composite.

It is found that 10%–20% enhancement of strength, ductility and toughness due to the incorporation of the continuous OF.

The continuous OFs are put into PLA first time to improve the strength. The fabrication method and process reported here are potentially applied in such engineering applications as aerospace, defense, auto, medicine, etc.

An energy-absorbing device is an important tool that is capable of increasing the survivability of passengers in vehicles. Generally, empty metallic tubes are used, and it is found that the energy absorption capability is lower than the energy obtained using composite materials. Therefore, this paper numerically presents the crushing performances of hybrid tubes under axial and oblique compressions.

Three important parameters are used such as fiber thicknesses, fiber orientations and oblique compression angles. Epoxy-reinforced fibers are wrapped around the steel tubes and it is then modeled numerically using the ANSYS finite element program. Belytscho – Tsay shell element is used to model the composites, while a bilinear kinematic hardening model is used to model the steel tube. A proper contact algorithm is implemented to prevent interpenetration among elements and surfaces.

A proper contact algorithm is implemented to prevent interpenetration among elements and surfaces. Hybrid tubes are quasi-statically crushed and force–displacement curves are extracted and analyzed.

It is found that the introduction of oblique compressions has induced bending moments and therefore decreases the energy absorption capability. Varying fiber orientations also insignificantly changed the crushing performances. However, wrapping carbon/epoxy composite that is capable of strengthening the tubes, is also subjected to oblique compression compared with the glass/epoxy composites.

Dref-3 friction spun core yarns produced using staple fibre yarn as the core, e.g. Jute core yarn wrapped with cotton fibre, have poorer mechanical properties compared to the core yarn itself. The purpose of this study was to understand the structure of such yarns, that will lead to the optimization of fibre, machine and process variables for production of better quality yarn from the Dref-3/3000 machines.

The Dref spinning trials were conducted following a full factorial design with six variables, all with two operative levels. The Dref-3 friction spun yarn, in which the core is a plied, twisted ring yarn composed of cotton singles and the sheath, formed from the same cotton fibres making the singles, has been examined. The structures have also been studied by using the tracer fibre technique.

It was observed that rather than depending on the plied core yarn, the tensile properties of the Dref-3 yarn are significantly determined by the parameters those affect the constituent single yarn tensile properties, i.e. the amount of twist and its twist direction, yarn linear density and the sheath fibre proportion used during the Dref spinning in making the final yarn. Further, when the twist direction of single yarn, double yarn and the Dref spinning false twisting are in the same direction, the produced core-sheath yarn exhibits better tensile properties.

The understanding of the yarn structure will lead to optimized production of all staple fibre core Dref spun yarns.

The research work may lead to utilization of coarse and harsh untapped natural fibres to the production of value-added textile products.

Though an earlier research has reported the effects of sheath fibre fineness and length on the tensile and bending properties of Dref-3 friction yarn, the present study is the first documented attempt using the tracer fibre technique to understand Dref-3 yarn structure with plied staple fibrous core.

The purpose of the paper is researching on the motion law of fiber in the vortex field inside the nozzle.

A three-dimensional calculation model was established using the MVS861 (Muratec Vortex Spinning) air-jet vortex-spinning nozzle as the prototype, and the fluid–solid coupling calculation module in the finite element calculation software ADINA (Adina System) was used to numerically analyze the fiber-air flow two-phase coupling. At the same time, the effect of the air pressure at the nozzle on the two-phase flow is studied.

The results show that after the air flow ejected through the nozzle, a vortex field will be generated in the flow field to push the internal fiber to move toward the nozzle outlet in a wave motion; as the air pressure at the nozzle increases, the fiber movement period becomes shorter and the oscillation frequency becomes higher; increasing the air pressure at the spray hole can improve the working efficiency of fiber twisting and wrapping.

The research present an effective and feasible theoretical model and method for the motion law of fiber in the vortex field inside the nozzle based on ADINA fluid–structure coupling model.

The paper aims to introduces an experimental work to investigate the torsional behavior of reinforced concrete (RC) beams strengthened by near-surface mounted (NSM) carbon fiber-reinforced polymer (CFRP) ropes.

In this research, nine rectangular RC beams of 250 mm × 300 mm cross-section and 1,600 mm in length were constructed and tested considering the studied parameters. These parameters include the length of the CFRP rope, the orientation of the CFRP rope, the arrangement of longitudinal and the scheme of NSM-CFRP ropes.

In comparison to control specimens, the results demonstrate a considerable improvement in the torsional response of RC beams strengthened with the CFRP rope. Additionally, specimens strengthened with 90° vertical ropes increase torsional moment capacity more efficiently than specimens strengthened with 45° inclined ropes since the stress concentration leads to premature debonding of the CFRP rope. Whereas RC beams' ability to withstand torsional moments is reduced as the distance between reinforcing CFRP ropes is increased. According to test results, adding CFRP ropes to RC beams' bottoms had a slightly positive impact on torsional response.

This paper fulfills an identified need to study how the using of the CFRP rope is effective in strengthening RC beam subjected to torsion moment.

Reinforced concrete structures have been wrapped to provide strength and confinement in the presence of seismic loads. The wrapping of structures as a means of mitigating corrosion is relatively recent. The objective of the work to be described is to investigate the long-term effectiveness of fiber-reinforced polymer (FRP) composite wraps in mitigating corrosion in reinforced concrete elements in severe environments.