Fabric Wrap Research Articles

Testing and evaluation of PVCC nano layered reinforced concrete T-beam: Experimental study

This study examines the performance of reinforced concrete T-beams strengthened with PVCC nano layering and basalt fiber fabric wrapping. TP3, a PVCC nano-layered specimen with 1.2% PVA fiber, and TB2, a basalt fiber fabric-wrapped beam, outperform the other specimens. TP3 has a first fracture load of 112 kN and a maximum ultimate load of 165 kN, with 1.66 times the ductility and 1.51 times the stiffness of the control beam (T0). TP3 also has 1.61 times more energy absorption and the highest energy index, 1.46 times that of T0. TB2 can withstand a maximum ultimate load of 185 kN and has higher ductility, stiffness, energy absorption, and energy index than T0. The experimental results are validated by finite element analysis, which provides useful insights into strengthening procedures in structural engineering applications.

Experimental investigation of the effect of fabric wrapping method and autoclave curing on the mechanical and thermal degradation of carbon nanotube doped and undoped carbon composite pipes

AbstractAlthough it is seen in the literature that composite pipes are produced by filament winding, there are limited number of studies on the use of fabric wrapping and autoclave. In this study, in order to fill this gap and contribute to the literature and industry, composite pipes were produced using fabric wrapping and autoclave methods together and their mechanical and thermal properties were investigated. The effect of carbon nanotube (CNT) reinforcement on these properties was also investigated. According to low velocity impact (LVI) test, 10%–25% impact strength increase was observed with CNT reinforcement. Thermogravimetric analysis (TGA) shows that mass loss decreased by ⁓10% and the degree of thermal degradation increased by ⁓10%. In dynamic mechanical analysis (DMA), it is observed that epoxy glass transition temperature (Tg) increased by 11% with CNT reinforcement. At the end of the study, the mechanical and thermal properties of the pipes produced by autoclave and fabric wrapping methods were improved compared to the literature and contributed to science and therefore to the increased use of prepreg carbon pipes in the industry.Highlights Composite carbon pipes were produced by applying prepreg fabric wrapping and autoclave curing methods together. The mechanical and thermal properties of multi‐walled carbon nanotube (MWCNT) reinforced and unreinforced carbon composite pipes were investigated. According to TGA, it was observed that the mass loss decreased. Thermal decomposition temperature increased for MWCNT reinforced and unreinforced samples. According to DMA, Tg of epoxy decreased for MWCNT unreinforced sample and increased for MWCNT reinforced sample.

Immobilization of phosphorus in sediment-water system by hydrous iron oxide and hydrous iron oxide/calcite mixture under feed input condition

The efficiency and mechanism of hydrous iron oxide (HFO) and HFO/calcite mixture to inactivate the phosphorus in the overlying water (OW)/sediment system under the feed adding condition were explored, and the effect of HFO and HFO/calcite mixture addition on the diversity, composition and function of bacterial communities in the sediment was examined. HFO and HFO/calcite mixture direct addition can effectively lower the concentration of soluble reactive phosphorus (RSP) and diffusion gradient in thin film-unstable phosphorus (PDGT) in OW and inactivate the PDGT in the upper sediment. The elimination efficiencies of RSP by the direct HFO and HFO/calcite mixture addition were 48.9–97.0 % and 42.4–95.4 %, respectively. The alteration in the addition mode from the one-time to multiple direct addition was beneficial to the immobilization of RSP and PDGT in OW and PDGT in the upper sediment by HFO and HFO/calcite mixture under the feed input condition in the long run. Permeable fabric wrapping reduced the inactivation efficiency of RSP in OW by HFO and HFO/calcite mixture, but it made the recycling of these materials possible. Most of P immobilized by HFO and HFO/calcite mixture was relatively or very stable. After the HFO and HFO/calcite mixture addition, the composition of bacterial communities in the surface sediment changed. However, the bacterial communities in the amended sediments still can perform good ecological function. Our findings suggest that HFO and HFO/calcite mixture are promising phosphorus-immobilization materials for the inactivation of RSP and PDGT in OW and PDGT in the upper sediment under the feed inputting condition.

Flexural Creep Behavior in Utilization of Woven Glass-Fibre as Reinforcement in Pultruded Glass Fibre-Reinforced Polymer Composite Cross-Arms: Experimental and Numerical Analysis

Pultruded glass fiber-reinforced polymer (PGFRP) composite is a relatively new material used to replace conventional wood in the fabrication of cross-arms for transmission towers. Much research has been undertaken on coupon-scale PGFRP composite cross-arms. However, a few have been completed on full-scale PGFRP composite cross-arms under actual operating load. Thus, this work investigates the effect of wrapping woven glass fiber fabric as an additional reinforcement on the creep reactions of PGFRP composite cross-arms installed in a 132 kV transmission tower. In the first stage of this research, the deflection of the original cross-arm under various loads ranging from 0 to 9 kN was evaluated and was followed by the actual working loads. This experiment was repeated on cross-arms wrapped with different numbers of glass fiber fabric layers around the weakest point of the beam. Then, the creep behaviors and responses of the woven glass fiber-reinforced cross-arms were evaluated and compared with the original cross-arms from the previous study. The actual operating load was applied to the PGFRP composite cross-arms for 1000 hours to study their capability to support the weight of electrical cables and insulators. In order to replicate the tropical climate, the cross-arm were mounted on a test rig in an open area. The findings of this study revealed that reinforcing the cross-arm by wrapping it with woven glass fiber fabric could extend its life and hence reduce the maintenance cost and effort for long-term usage. The finding of this study will also become essential knowledge on woven fabric wrapping applications on square profiles.

Experimental and Numerical Study of Strengthening Prestressed Reinforced Concrete Beams Using Different Techniques

This study aimed to evaluate the static response of prestressed reinforced concrete beams strengthened in their flexure and shear properties using different strengthening techniques, steel plates, and externally bonded woven carbon fiber fabric (WCFF). The experimental work involved testing twenty large-scale prestressed reinforced concrete beams with a length of 3000 mm, and cross-sections measuring 400 mm in height and 200 mm in breadth were cast in the factory and tested in the laboratory. Four beams without prestressing served as the reference beams; two unbonded pre-tensioned beams served as the control beams, and the remaining fourteen beams were strengthened with steel plates and externally bonded woven carbon fiber fabric (WCFF). Eight of the beams were strengthened with 4 mm thick steel plates and tested under a monotonically increasing load with manual readings recorded. The remaining six beams were strengthened with 0.5 mm thick WCFF and tested under a monotonically increasing load with manual readings recorded. The variables considered included the strengthening techniques (FRP composite sheets, steel plates), the types of strengthening (slices, U-shaped), and the flexural and shear capacities of the strengthened beams. All the implemented strengthening techniques yielded enhancements in both the flexural and shear strength outcomes of the beams compared to their respective controls. The most significant increase in load capacity, whether in terms of ultimate load or first crack load, for the prestressed concrete beams’ flexure properties occurred when strengthening with U-shaped steel plates. Additionally, the greatest reduction in deflection at the point of reaching the maximum load for the prestressed concrete beams, in terms of their flexure properties, was observed when strengthening with U-shaped steel plates. Similarly, the maximum load increase for the prestressed concrete beams, in terms of their shear properties, was achieved through strengthening with U-shaped woven carbon fiber fabric wrapping. Furthermore, a finite element model was created to simulate various experimental specimens. The finite element model’s results exhibited harmony with the experimental results, affirming the efficacy of the presented finite element model.

Enhancing melon growth and sustainability through spun-bonded polypropylene fabric wrapping

This study aimed to assess various weights of spun-bonded nonwoven polypropylene (PP) fabrics for wrapping outdoor-grown melons, providing cost-effective options for both construction and insect protection. Fruit wrap bags were crafted using different materials, and spun-bond fabrics with weights of 30, 40, 50, and 60 gsm were tested for encasing melons. The results demonstrated that the 50 gsm spun-bonded bags significantly improved melon growth after a four-week period, establishing them as the preferred choice for outdoor melon cultivation. To evaluate their growth in comparison to unwrapped fruits, we measured melon circumference after four weeks. Unwrapped melons exhibited the slowest growth, whereas those enveloped in 50 gsm spun-bond fabric displayed the most substantial growth. Additionally, we employed hanging weights to gauge melon development. Melons encased in 30, 40, 50, and 60 gsm spun-bond fabric weighed 663, 680, 707, and 870 grams, respectively. Significantly, melons wrapped in 50 gsm spun-bond fabric exhibited the highest weight gain, underscoring its effectiveness. This study highlights the potential of spun-bonded PP fabric as a sustainable packaging option and a growth enhancer for melons, contributing to sustainable agriculture and improved crop quality.

SG-APSIC1130: Zero wet pack Pimporn Sirikraiwattanawong, Thailand

Objectives: We noted moisture in Thompson retractor sets after steam sterilization in our hospital. Moisture can cause severe problems leading to potentially contaminated instruments that carry infection risk to patients and cause procedure delays, wasted time and effort, greater workload, and higher costs. We sought to reduce the number of retractor sets with moisture to zero. Methods: The central sterile supply (CSS) team discussed the cause of the problem. We hypothesized that temperature difference between the sterilizer chamber and inside the container might create condensation and thus moisture in the final surgical set. We collected and analyzed data and proposed an experiment to improve the sterilization process. We performed a trial of sterilization process improvements pertaining to proper loading technique and the packaging process. We also evaluated the appropriate drying time for rigid containers. We then rearranged the process and adjusted the cooling time from 30 to 60 minutes after steaming. Results: Moisture in Thompson retractor packs occurred because of thicker, rigid containers. We removed the previous type of lining material to separately steam the rigid surgical instrument, and we extended the cooling time to 60 minutes. We updated standard operation procedures and continued to monitor and re-evaluate the process. Conclusions: We identified the primary cause of moisture in Thompson retractor sets after steam sterilization. We illustrated that avoiding sterilizer overload, avoiding contact with fabric wrapping materials, and proper cooling time kept the pack moisture free. Occurrences of moisture in surgical packs after sterilization should be reported and handled efficiently by CSS personnel to preserve quality and avoid waste.

Structural retrofitting of impaired dapped-end beams: a review

The geometric reduction prevailing in dapped-end concrete beams forms a disturbed region into the beam-ends. Consequently, material deterioration- and reinforcement-detailing issues prevailing in the end region cause a series of structural distresses. In this light, distresses in dapped-end beams and potential retrofitting options are reviewed in this paper. It is found that the choice of the retrofitting configuration is governed considerably by the prevailing defect. The strength enhancement could be as high as 40%–50% upon the choice of correct configuration whereas possibly be negligible upon inappropriate selection. Generally, the use of diagonal bars and plate jacketing are promising with steel applications. The bars can be prestressed to enhance the retrofitting efficiency. For fibre-reinforced polymer applications, inclined/horizontal stripping and fabric wrapping are impressive approaches, while combined systems show better results. The review also identifies the required future research for formulating comprehensive retrofitting guidelines.

Using a Church as a Temporary Auditorium. Acoustical Design of S. Domenico of Imola

In Europe, many of the ancient buildings, especially sacred architecture, are subject to renovation projects by converting their initial occupation type for temporary exposition. In particular, the demand for assisting to live musical performance is increased considerably in Italy because of the missing of places dedicated to the performing arts. As such, one of the churches of Imola (i.e. San Domenico), located approximately 30 Km far from Bologna, has been requested by citizens to be adapted into an auditorium when necessary. Based on needs expressed by the local population, this paper recommends one of the possibilities of how the acoustical design can be applied to the church in order to adjust the main volume to the realization of transient musical venues, cancelling any undesirable reflections that can lower the quality perception of sound. The actual acoustics has been adapted in order to reach both speech and musical intelligibility, especially focused on sacred music style. Both measured and simulated results have been compared determining the choice of the proposed acoustical solutions in terms of type of finishes and surface area to be covered by the added materials. The suitable treatments in consideration include absorbing wooden panels, curtains and fabric wrap.

Comparative Investigation on Torsional Behaviour of RC Beam Strengthened with CFRP Fabric Wrapping and Near‐Surface Mounted (NSM) Steel Bar

Many researchers worldwide have extensively used fibre‐reinforced polymer (FRP) strengthening materials and near‐surface mounted (NSM) to enhance the shear and flexural strengths of reinforced concrete (RC) beams. However, studies on torsional strengthening are limited. Although a few studies have focused on torsional strengthening, none of them simultaneously investigated torsion with shear and/or bending moment. This study aims at demonstrating the behaviour of RC beams strengthened with FRP sheets (strips) with different configurations and NSM steel bars with different spacing that was subjected to combined actions of torsion and bending moment and making a comparison between them. Seven beams with a dimension of 15 × 25 × 200 cm were casted. One of the beams was not strengthened; three of them were strengthened with carbon FRP, and the others were strengthened with NSM steel bar. The angle of twist at torque intervals, first cracking torque, ultimate torque, and ultimate twist angle of the conventional and strengthened beams during the testing process are compared. Results show a significant improvement in the torsional performance of RC beams using carbon FRP and NSM steel bar. The test beams that were strengthened with CFRP wrapping showed better enhancement in the ultimate torsional moment as opposed to the beams that were strengthened with NSM steel bar.

International law at the United Nations: does it matter?

In 1926, the creation of the International Institute for the Unification of Private Law (U nidroit ) as an auxiliary organ of the League of Nations could have appeared almost as a visionary challenge, given the complex and turbulent historical moment. In fact, in those days, the clouds of tragedy of the First World War had not been driven away by the new era of peace and cooperation but, rather, by the first winds, the first signs of an international tension that would later unleash the Second World War. This challenge, far from being visionary or useless, was reading the future instead: it predicted the future decades in advance. That young Institute was to play a key role in a context of international relations that every day would become increasingly interdependent and, finally, in the most recent decades we have been living, even globalized. Today, more than ever, the political and economic architecture of a globalized world needs a solid foundation. In a word, it needs to be based on a common and uniform law that grants stability, predictability, and certainty to the international political and economic relations in order to also ensure fairness, justice, and equality of treatment between nations, through the modernization, harmonization, and coordination of private and trade law. For 90 years, the activities of U nidroit have represented an invisible web, a fine fabric wrapping international relations, giving them the stability and certainty that is a necessary prerequisite for a peaceful and cooperative world. It has been a continuous and complex effort that was relaunched in an even more ambitious and in some ways more visionary way in 1940, when at the eve of the tragedy of the Second World War, the Institute survived the failure of the League of Nations and regained life and autonomy as an intergovernmental organization based on a statute.

Comparative Experimental Study on Torsional Behavior of RC Beam Using CFRP and GFRP Fabric Wrapping

Fiber reinforced polymer (FRP) as an external reinforcement is used extensively to enhance the strength requirement related to flexure and shear in structural systems. But the strengthening of members subjected to torsion is yet to be explored as Torsion failure is a brittle form of failure. In present experimental study deals with the torsional strengthening of Reinforced Concrete beams using epoxy bonded Fiber- Reinforced Polymer (FRP) fabric. Total Thirty nine rectangular beams of size 150mm × 300mm and 1200 in length are casted. Out of which, three beams are control beam and remaining thirty six beams are classified into two groups. One with CFRP fabric wrapping and another with GFRP fabric wrapping. With various wrapping patterns. The applied CFRP and GFRP configurations are U-jacketed, vertical strips with spacing, and edge strips along with vertical strips along its entire length. Torsional capacity of beams of two groups is compared with control specimen with respect to torsional moment, angle of twist and ductility factor and it was observed that CFRP fabric bonded beam shows more torsional strength than the GFRP bonded beam.

Retrofitting of the Historic Castagnara Bridge in Padua, Italy, with Fibre Reinforced Plastic Elements

Masonry arch bridges are typically historical infrastructures that were often not designed to withstand the heavy truck traffic that they are currently carrying and therefore must be replaced by modern concrete or steel bridges. Usual methods of strengthening masonry bridges are neither simple nor economical. This paper investigates whether the application of composites in the form of either a fabric wrap or laminate strips to masonry constructions may increase the load-bearing capacity of these structures. This research project demonstrates how advanced composite materials can be used to strengthen existing masonry arch bridges in order to increase their load-bearing capacity.This paper details the methodology adopted to retrofit and repair the Castagnara masonry bridge in Padua (Italy) and the investigations related to the damage of the bridge, the retrofitting by fibre reinforced plastic (FRP) elements and the results of the consolidation. Retrofitting involves the insertion of a prestressed steel cable into the abutments, consolidating injections, bonding by FRP strips on the extrados of the deck and demolition and reconstruction of the reinforced concrete slab. Linear-elastic and non-linear dynamic analysis of the bridge have been performed. Detailed finite element models (FEM) and on-site dynamic acceleration measurements were used to evaluate retrofit performance. Results show that applying carbon fabric to the masonry bridges provides significant increases in bending and shear capacity.However, a statistically significant number of masonry structures strengthened with carbon fibres need to be tested to arrive at definitive stress modification factors.

Durability-Based Ranking of Typical Structural Repairs for Corrosion-Damaged Marine Piles

Corrosion damage is a main cause of deterioration for concrete marine structures. It has become increasingly important to rehabilitate structures and develop repair techniques that prolong their life cycles. This investigation compares the performance of recognized repair techniques, in terms of corrosion resistance, structural integrity, and cost-effectiveness. Eight sets of three cylindrical piles were prepared to conduct seven types of repairs with one control set. Following initial exposure to corrosion, the specimens were repaired using the proposed techniques and tested for durability under simulated tidal conditions, with corrosion monitoring, determination of time-to-corrosion threshold, and visual inspections. The structural integrity was determined by crack scoring and ultimate load testing, and synthesized with a cost-effectiveness evaluation to rank the repair techniques. The repairs comprising carbon wrapping, high-density polyethylene (HDPE) jacketing, and MMFX steel outperformed the others, slurry-infiltrated fibrous concrete (SIFCON) repair, styrene-butadiene grout with woven roving fabric wrapping, normal concrete repair with spliced fiberglass reinforcing plastic (FRP) (glass) reinforcement, and the modified ASANO refresh method.

BHOPAL’S LEGACY Union Carbide acquisition shadows Dow at London Olympics

Thousands of people perished in 1984 when a pesticide plant in Bhopal, India, leaked methyl isocyanate gas. The legacy of that industrial accident—the world’s worst—continues to haunt Dow Chemical , which bought the plant’s majority owner, Union Carbide, in 2001. On Nov. 15, the appropriateness of Dow’s sponsorship of the 2012 Olympic Games in London was questioned at a U.K. parliamentary hearing. Dow is a global partner of the International Olympic Committee and has funded an $11 million fabric wrap that will surround the Olympic Stadium next summer. Members of Parliament on the Culture, Media & Sport Committee expressed concern about Dow’s environmental, ethical, and social ideals. But Sebastian Coe, an Olympic gold medal winner, former member of Parliament, and chair of the London Organising Committee of the Olympic & Paraolympic Games, defended the sponsorship. “We are satisfied that Dow were not the owners, the operators, or were involved with that plant at ...

Investigation into CFRP laminate anchorage systems utilising bi-directional fabric wrap

The increasing challenges faced to strengthen existing concrete bridges and infrastructure has resulted in intensive research and the introduction of carbon fibre reinforced polymers (CFRP). It has been demonstrated that failure of concrete structures retrofitted with CFRP usually occurs by de-lamination of the CFRP from the concrete substrate. As a result, the introduction of CFRP anchorage systems to increase the efficiency of CFRP solutions remains an area of great potential. What follows is the third paper of a series presenting the results of six types of CFRP anchorage solutions. Earlier publications highlighted the benefits of uni-directional fibres and of mechanical substrate strengthening. Together these formed anchorage types 1, 2 and 3 designed to enhance CFRP anchorage performance. The present paper focuses on the application of CFRP bi-directional fabric to the ends of CFRP laminates in arrangements that form the remaining anchorage types 4, 5 and 6. The benefits of the bi-directional CFRP anchorage system has resulted in significantly improved: fibre utilisation levels and increased ductility, which in some cases has resulted in laminate rupture. The higher CFRP strain levels achieved warrants the adoption of less stringent strain limitations used in design, resulting in both material and cost savings.

Investigation into CFRP plate end anchorage utilising uni-directional fabric wrap

Carbon fibre reinforced polymers (CFRP) has become a very popular method of improving the capacity of structural elements. Failure of CFRP strengthening systems when applied to concrete structures is usually typified by de-lamination of the CFRP from the concrete substrate. Research has shown that anchoring the ends of the CFRP plates or sheets can result in a significantly higher load/stress being reached before de-bonding occurs and that when sufficiently anchored, the CFRP material strain at failure can approach its ultimate strain at rupture. The following is continuation of experimental studies into CFRP anchorage systems used to retrofit concrete structures. It follows from previous investigations conducted by the authors into the bond behaviour of a new anchorage system utilising a mechanically strengthened substrate. The paper presents two alternative anchorages; both utilising uni-directional fabric wrap oriented horizontally across and parallel to the direction of the laminate. Both forms of anchorage are found to be effective in increasing the CFRP to concrete bond strength by distributing contact stresses over a greater area of concrete.

Compression Tests of Circular Timber Column Confined with Carbon Fibers Using Inorganic Matrix

Many engineering wooden components in our nation's infrastructure are deteriorating and are in need of repair and strengthening. Timber piles, timber poles, timber posts, and naval fender systems are examples of timber infrastructure elements that are experiencing significant deterioration due to moisture, extreme temperatures, and weathering and are in need of repair and upgrade. The use of fiber-reinforced polymer composites (FRPC) has proven to be effective in rehabilitating and upgrading infrastructure elements. FRPC are also now being considered for new structures to improve strength, ductility, predictability, and durability. This note describes an experimental investigation of circular columns made of poplar wood confined with carbon fibers in an inorganic matrix and subjected to axial compression. Results from this study showed that carbon fiber confinement increased strength, stiffness, ductility, and reduced the variability in timber column behavior under axial loads. The study showed that the full fiber wrap and full fabric wrap confinement were more effective than spirals and hoops and will make the timber column behavior much more reliable and provide protective coating.

Laparoscopic aortic reinforcement and endovascular graft placement in swine: A new external wrap

To evaluate the feasibility, safety, and histological response of laparoscopic external aortic wrap implantation in conjunction with an endovascular stent/stent-graft placement in the infrarenal aorta in a porcine model. Seven swine underwent laparoscopic retroperitoneal placement of a custom-made Dacron fabric wrap placed around the infrarenal aorta to create a landing zone for an endovascularly placed aortic stent/stent-graft. Technical success was achieved in all animals without any major complications. Follow-up ranged from 1 to 4 weeks. At necropsy, the external wraps were well incorporated into the adventitia, and the stents/stent-grafts were well incorporated into the intima. Small patches of medial necrosis of the aortic wall were observed in one animal in the stent model and in two animals in the stent-graft model. There was no transmural necrosis observed. CONCLUSIONS This adjunct technique, an external wrap around the infrarenal aorta combined with endovascular grafting, is feasible and deserves further studies into how it may be used to facilitate endovascular repair of aortic aneurysms. We hypothesize that our new device could provide capability of altering the proximal neck morphology of abdominal aortic aneurysm and reinforcement to the aortic wall. This, in turn, could improve eligibility for endovascular aneurysm repair and prevent or treat type I endoleak and graft migration. Future investigations will involve evaluation of the long-term effect of the external aortic wrap on the integrity of the aortic wall in an animal model and testing the clinical usefulness of this new technique.

Compressive behaviours and failure modes of concrete cylinders reinforced by glass fabric

Concrete cylinders reinforced with glass fabrics of various constructions were fabricated. Compressive behaviours and failure modes of cylinders with and without fabric wrapping were compared. The tensile strength of the filament used in the fabric, the fabric thickness and the fabric weight played an important role as far as the anti-compression behaviour and failure mode of the reinforced cylinders are concerned. Tensile strength of the fabric is not considered to be a main factor for the reinforcement effect. Enhanced reinforcement would make the broken section of the wrapped fabric shift towards the middle section of the concrete cylinder.