Weight Change and Mechanical Properties of GRP Panel in Hot Water

1989 ◽  
pp. 259-277 ◽  
Author(s):  
Hiroyuki Hamada ◽  
Atsushi Yokoyama ◽  
Zen-Ichiro Maekawa ◽  
Tohru Morii
Materials ◽  
2020 ◽  
Vol 14 (1) ◽  
pp. 155
Author(s):  
Régis Pamponet da Fonseca ◽  
Janaíde Cavalcante Rocha ◽  
Malik Cheriaf

The addition of natural fibers used as reinforcement has great appeal in the construction materials industry since natural fibers are cheaper, biodegradable, and easily available. In this work, we analyzed the feasibility of using the fibers of piassava, tucum palm, razor grass, and jute from the Amazon rainforest as reinforcement in mortars, exploiting the mechanical properties of compressive and flexural strength of samples with 1.5%, 3.0%, and 4.5% mass addition of the composite binder (50% Portland cement + 40% metakaolin + 10% fly ash). The mortars were reinforced with untreated (natural) and treated (hot water treatment, hornification, 8% NaOH solution, and hybridization) fibers, submitted to two types of curing (submerged in water, and inflated with CO2 in a pressurized autoclave) for 28 days. Mortars without fibers were used as a reference. For the durability study, the samples were submitted to 20 drying/wetting cycles. The fibers improved the flexural strength of the mortars and prevented the abrupt rupture of the samples, in contrast to the fragile behavior of the reference samples. The autoclave cure increased the compressive strength of the piassava and tucum palm samples with 4.5% of fibers.


2009 ◽  
Vol 631-632 ◽  
pp. 199-204 ◽  
Author(s):  
Yoshimi Watanabe ◽  
Yoshimi Iwasa ◽  
Hisashi Sato ◽  
Akira Teramoto ◽  
Koji Abe

Ti and Ti alloys are widely used as metallic implants, because of their good mechanical properties and nontoxic behavior. However, they have problems as the implant-materials, namely, high Young’s modulus comparing that of bone and low bonding ability with bone. There is a need to develop the Ti and Ti alloys with lower Young’s modulus and good bonding ability. In previous study, Ti composite containing biodegradable poly-L-lactic-acid (PLLA) fiber has been fabricated to improve these problems. However, this composite has low strength because of the imperfect sintering of Ti matrix. To improve its strength, sintering of Ti matrix should be completed. In this study, Ti-NaCl composite material was fabricated by spark plasma sintering (SPS) method using powder mixture of Ti and NaCl to complete the sintering of Ti matrix. To obtain porous Ti samples, Ti-NaCl composite were put into hot water of 100 oC. The porous Ti was dipped into PLLA melt in order to introduce PLLA into the pores of porous Ti. Finally, Ti-PLLA composite was obtained, and PLLA plays a role as reinforcement of Ti matrix. It was found that the Ti-PLLA composite has gradient structure and mechanical properties.


Author(s):  
Tjokorda Gde Tirta Nindhia ◽  
Zdenek Knejzlík ◽  
Tomáš Ruml ◽  
I Wayan Surata ◽  
Tjokorda Sari Nindhia

Silk can be produced by spider or insect and have prospect as biomaterial for regenerative healing in medical treatment. Silk having physical and chemical properties that support biocompatibility in the living things..In this research, silk that was obtained from Indonesia natural resource of Attacus atlas silkmoth was explored and then will be  developed for biocompatible biomaterial. The treatment with NaOH was developed to separate the fiber from the cocoon. The obtained fiber is investigated its mechanical property by performing tensile test for single fiber. The biocompatibility testing was conducted with human cell (osteosarccoma) cultivation. The result identify that separation by using NaOH yield better better mechanical properties comparing konvenstional method with boiling in hot water. Biocompatibility testing indicate that the the fiber having good biocompatibility.


Author(s):  
E. Rajamäki ◽  
M. Leino ◽  
P. Vuoristo ◽  
P. Järvelä ◽  
T. Mäntylä

Abstract Three different types of polyethylene powders were flame sprayed onto pre-heated steel substrate previously coated by electrostatic spray system with a thin epoxy primer layer. Properties of the polyethylene (PE) powders, including powder density, particle size and melt flow rate (MFR) were measured in order to study their influence on the mechanical properties of the coating. The spray experiments started with optimization of spraying parameters. The main variables were pre-heating temperature of the substrate, temperature increase during spraying (influenced by the spraying distance), and thickness of the PE coatings. The laboratory tests performed for the coatings were coating characterization by microscopy and mechanical testing. Porosity and thickness of the coatings were determined by optical and stereo microscopy studies from polished cross-sectional samples. Hardness, impact strength, peel strength, and adhesive strength of the coatings were also investigated. Also some hot water sinking and heat cycling tests were performed. As a result from the present studies it can be concluded that powder properties have great influence on the mechanical properties of the final coating.


2019 ◽  
Vol 131 ◽  
pp. 01127
Author(s):  
Wen Wen Yu ◽  
Jian Gao Shi ◽  
Yong Li Liu ◽  
Lei Wang

Ultra-high molecular weight polyethylene (UHMWPE) and graphene (GR) was melt compounded by reactive extrusion. Nanocomposite monofilaments were prepared by melt spinning through a co-rotating screw extruder and drawing at hot water. GR/UHMWPE nanocomposite ropes were twisted using nanocomposite monofilaments. A structure and mechanical properties of the GR/UHMWPE nanocomposite monofilaments and its ropes had been characterized by scanning electron microscopy (SEM), and mechanical test. Results showed that the monofilaments surface of monofilaments became rougher with introducing of GR nanosheets, which could be related to stacking of GR. The breaking load of GR/UHMWPE nanocomposite ropes was remarkably improved upon nanofiller addition, with the decrease of the elongation at break.


Author(s):  
Ying Yu ◽  
Shinichiro Kawabata ◽  
Yuqiu Yang ◽  
Hiroyuki Hamada

As well known, the corrosion resistance and durability of the material are always considered in the safety design of the materials. In this study, the jute fabric from recycled coffee bags was used to fabricate ecologically friendly composites. Jute fabrics with two kinds of different moisture contents were used to fabricate the natural fiber reinforced composites, and the hot water immersion properties have been evaluated. Additionally, the effects of the hybridization with glass woven fabric laminated structures were also investigated. Jute/Jute laminated composite, Jute/Jute/Glass, and Glass/Jute/Glass laminated hybrid composites had been fabricated by hand lay up method. A preliminary investigation on the effect of moisture contents of the jute fabric on the mechanical properties of the jute and jute/glass hybrid composites was discussed based on the results of 3 point bending test. Moreover, the durability of the composites in the hot water immersion was also evaluated. The effects of hot water immersion on the mechanical properties were investigated by the way of 3 point bending test. The specimens were immersed in hot water maintained at 80°C with the immersion time of 24, 120 and 240 hours. Specimens were taken out from the hot water at the same time and repeated the 3 point bending test after each immersion time and the weight changes had been measured. Results showed that the Jute/Jute composite absorbed water easily, and it could be noted that all of the natural dried composites showed comparable higher water absorbed value to the deeply dried ones. The bending strength after aging decreased remarkably. In particularly, all of the natural dried composites showed higher bending strength than the deeply dried one before aging. However, after 120 hours aging, on the contrary, almost the deeply dried composites showed comparable higher value to the natural dried ones. That could be due to the better bonding between fiber and matrix for the deeply dried composites which decreased the water absorption of the composites. Additionally, the hybrid structure is effective in protecting the composites from water absorbing especially for the Glass/Jute/Glass hybrid one.


Holzforschung ◽  
2014 ◽  
Vol 68 (8) ◽  
pp. 933-940 ◽  
Author(s):  
Yao Chen ◽  
Nicole M. Stark ◽  
Mandla A. Tshabalala ◽  
Jianmin Gao ◽  
Yongming Fan

Abstract The water sorption and mechanical properties of wood-plastic composites (WPCs) made of extracted and delignified wood flour (WF) has been investigated. WF was prepared by extraction with the solvent systems toluene/ethanol (TE), acetone/water (AW), and hot water (HW), and its delignification was conducted by means of sodium chlorite/acetic acid (AA) solution. A 24 full-factorial experimental design was employed to determine the effects of treatments and treatment combinations. WPCs were prepared with high-density polyethylene (HDPE) and treated WF was prepared by means of extrusion followed by injection molding, and the water absorption characteristics and mechanical properties of the products were evaluated. WPCs produced with extracted WF had lower water absorption rates and better mechanical properties than those made of untreated WF. WPCs containing delignified WF had higher water absorption rates and improved mechanical performance compared with those made of untreated WF.


2018 ◽  
Vol 162 ◽  
pp. 02014
Author(s):  
Mazin Abdulrahman ◽  
Alyaa Al-Attar ◽  
Marwa Ahmad

Reactive Powder Concrete (RPC) is an ultra-high performance concrete which has superior mechanical and physical properties, and composed of cement and very fine powders such as quartz sand and silica fume with very low water/ binder ratio and Superplasticizer. Heat treatment is a well-known method that can further improve the performance of (RPC). The current research including an experimental study of the effect of different curing conditions on mechanical properties of reactive powder concrete (compressive strength, modulus of rupture and splitting tensile strength), the curing conditions includes three type of curing; immersion in water at temperature of 35 OC (which is considered as the reference-curing situation), immersion in water at temperature of 90 OC for 5 hours daily and curing with hot steam for 5 hours daily) until 28 days according to ASTM C684-99 [8]. This research includes also the study of effect of adding silica fume as percentage of cement weight on mechanical properties of reactive powder concrete for different percentage ratios (5%,10% and 15%). Super plasticizer is also used with ratio of (1.8%) by weight of cementitious material; constant water cement ratio (0.24) was used for all mixes. For each reactive concrete mix, it has been cast into a cubes of (150*150*150) (to conduct the compression test), a cylinders of 150mm diameter with 300mm height (to conduct split test) and prisms of (500*100*100)mm to conduct the modulus of rupture test. The results showed that the best method of curing (according to its enhancing the RPC mechanical properties) is the method of immersion in hot water at temperature 90 OC for the all silica fume percentages, and the best used silica fume percentage was (10%) for the all used curing methods.


2011 ◽  
Vol 11 (2) ◽  
pp. 101-106
Author(s):  
C. Pereira-Loch ◽  
R. Benavides ◽  
M. Fogliato S. Lima ◽  
B.M. Huerta

AbstractImmobilization devices in radiotherapy are made of a soft plastic easy to mould when immersed in hot water. Same item is usually used for 6 patients (according to protocol), but at Hospital Sao Jose (HSJ) they have been showing some deformation during the re-utilization process. The latter is the reason for this research where devices were treated with 6 thermal conditions, 6 irradiation procedures and the joint effect of both treatments. DSC, TGA and WAXD indicated devices are made of polycaprolactone (PCL), but no signs of degradation, except a slight variation in crystalinity; however, mechanical properties by means of Young’s modulus steadily increase its values through number of treatments up to a 20%. Activation energy (Ea) obtained by multi-ramps of TGA-Arrhenius evaluated for the most treated samples (6th treatment) indicates that temperature facilitates degradation while irradiation and joint treatments enhance the stability of PCL, apparently by crosslinking.


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