scholarly journals The numerical simulation of Influence of Drying-wetting Cycles on the Deterioration Characteristics of Gypsum Rocks under Particle Flow Code

2020 ◽  
Vol 24 (1) ◽  
pp. 55-59
Author(s):  
Guopeng Wu ◽  
Wenwu Chen ◽  
Kai Cui
Keyword(s):  
Mechanical Properties ◽  
Numerical Simulation ◽  
Water Absorption ◽  
Absorption Rate ◽  
Early Stage ◽  
Particle Flow ◽  
Wetting And Drying ◽  
Water Absorption Rate ◽  
Gypsum Rock ◽  
Deterioration Characteristics

In order to study the influence of dry-wet cycling on the deterioration characteristics of gypsum rocks and solve the problems encountered in engineering construction, in this study, gypsum rocks are taken as the research object. With the combination of laboratory test and theoretical analysis, the numerical simulation of particle flow is carried out, and the deterioration characteristics of physical and mechanical properties of gypsum rock under dry-wet cycling are studied. The results show that gypsum, quartz, zeolite and dolomite are the main components of gypsum rocks. Gypsum occupies the most components in gypsum rocks, so the various characteristics of gypsum greatly affect the characteristics of gypsum rocks. The process of water absorption and loss of gypsum is similar, which shows that the rate of water absorption or loss of gypsum is faster in the early stage, and tends to be stable in the later stage. The curve of the whole process of water absorption and loss is fitted by negative exponential function, and the effect is better. The larger the porosity of gypsum rock is, the better its water absorption performance is. Intergranular pore, dissolution pore and dissolution pore are the main pore types of gypsum rock. Intergranular pore is the main water absorption channel of gypsum rock. The cumulative water absorption increases with the increase of wetting and drying cycles. The change of water absorption curve is mainly manifested in water absorption rate and time. The more the number of wet-dry cycles is, the higher the water absorption rate in the early stage of water absorption is, the closer the characteristic curve to the coordinate axis of water absorption is, and the shorter the water absorption time is. In contrast, the shape difference of water loss curve is very small. It can be seen from this that in the process of wetting and drying cycle, the hydrophysical and hydrochemical processes promote each other, which changes the crystal structure and pore structure of gypsum rocks, reduces the crystal strength and increases the porosity, thus leading to the deterioration of the mechanical properties of gypsum rocks.

scholarly journals The Physical and Mechanical Properties of Corn-based Bioplastic Films with Different Starch and Glycerol Content

2021 ◽  
Vol 32 (3) ◽  
pp. 89-101
Author(s):  
Nur Nadia Nasir ◽  
◽  
Siti Amira Othman ◽  
Keyword(s):  
Mechanical Properties ◽  
Water Absorption ◽  
Absorption Rate ◽  
Corn Starch ◽  
Physical And Mechanical Properties ◽  
High Strength ◽  
Major Drawback ◽  
Water Absorption Rate ◽  
Strength And Stiffness ◽  
Mechanical Tensile

Petroleum-based plastics have had a long history with varied materials and applications. However, the major drawback with these plastics is their harmful impact on the environment. Poor disposal management of these plastics have ultimately affected humans. Therefore, starch-based bioplastics have been widely used because of their renewability, sustainability and cost-effectiveness. This work investigated the effect of different concentrations of corn starch (10%, 15%, and 20% w/w of distilled water) and glycerol (20%, 30%, and 40% w/v of corn starch) on the properties of corn-based bioplastic films. Particularly, mechanical (tensile strength, Young’s modulus and elongation at break) and physical (water absorption rate and moisture content) properties were investigated. These films were prepared by the solvent casting method. It was demonstrated that the addition of 30% glycerol produced mechanical properties closest to the standard value, while films with a composition of 15% of corn starch had the most optimised value. Meanwhile, 20% glycerol and 20% corn starch produced a film with high strength and stiffness but lacked flexibility. Higher concentrations of starch and glycerol produced the highest moisture and water absorption rate. This was due to the highly hydrophilic nature of both corn starch and glycerol. However, the concentration of glycerol needs to be adjusted based on the intended use of the film. In conclusion, the concentration of corn starch and glycerol produced slightly different outcomes. Thus, the properties and application of the cornbased bioplastic films can be maximised by optimising the concentration of corn starch and glycerol.

Mechanical and Tribological Characterization of Hybrid Natural Fiber Reinforced Composites

2020 ◽  
Vol 12 (2) ◽  
pp. 136-143
Author(s):  
Hiral H. Parikh ◽  
Harshit P. Soni ◽  
Deval A. Suthar ◽  
Dhruv H. Patel
Keyword(s):  
Mechanical Properties ◽  
Water Absorption ◽  
Absorption Rate ◽  
Natural Fiber ◽  
Epoxy Composite ◽  
Natural Fibers ◽  
Synthetic Fiber ◽  
Test Results ◽  
Fiber Reinforced ◽  
Water Absorption Rate

Background: The technological enhancement in various disciplines enhances the demand for the new material which can replace the conventional materials. This has initiated the idea of composite materials. Synthetic fiber reinforced polymer matrix composites are being widely used due to its mechanical properties, but these fibers lack in terms of biodegradability, initial processing cost, recyclability and health hazard. An alternative to tackle these drawbacks can be found in natural fibers, that give an advantage in terms of strength to weight ratio, ease of availability and biodegradability. Methods: This work is aimed to determine the effect of hybrid basalt - banana reinforced epoxy composite and their effectiveness in substituting few conventional materials in terms of their mechanical properties, wear resistance and water absorption rate. Results: Basalt Banana Hybrid Composite (BBHC) is tested for their mechanical strength, hardness, impact strength, flexural strength, wear rate and water absorption rate. The test results of mechanical properties for the BBHC are compared to the other hybrid materials and conventional materials. Conclusion: The test results reveal that the hybrid basalt banana epoxy composite is a good substitute over various conventional materials. The water absorption test results reveal that the hydrophilic nature of the natural fibers reduces a lot after the hybridization.

scholarly journals Effects of Chemical Treatment on Mechanical Properties of Oil Palm Empty Fruit Bunch (EFB) with Urea Formaldehyde (UF) Resin Particleboardtype

2020 ◽  
Vol 8 (5) ◽  
pp. 1330-1334
Keyword(s):  
Mechanical Properties ◽  
Water Absorption ◽  
Oil Palm ◽  
Chemical Treatment ◽  
Absorption Rate ◽  
Urea Formaldehyde ◽  
Bending Test ◽  
Empty Fruit Bunch ◽  
Water Absorption Rate ◽  
Uf Resin

Oil palm plant by-product such empty fruit bunches (EFB) are not effectively utilized and in many instances had caused severe pollution problems. It has a potential to replace the wood in the production of particleboard in furniture industry. This research aim is to investigate the effects of the chemical treatment on the mechanical properties of the oil palm empty fruit bunch (EFB) with urea formaldehyde (UF) resin particleboard through Scanning Electron Microscopy (SEM), flexural test – three point bending test and the water absorption test. A single layered oil palm EFB/UF particleboard with the fibres treated with NaOH of 0.5%, 1.0% and 1.5% concentrations were made. Testing procedure was done in accordance with the American Standard Testing Materials - ASTM 1037 standard for testing wood based fibre and particle panel materials. The SEM images of 1.0% NaOH treated fibre shows a rougher surface indicating that more silica bodies are detached from the EFB surface which improves the mechanical interlocking ability of the fiber. Flexural properties the treated EFB/UF particleboard shows an improved quality compared to the untreated board. There is significant increase of 82% and 81% in the flexural strength and flexural modulus respectively of the 1.0% NaOH treated board from 0.5% NaOH treatment. As for the water absorption rate, the treated particle board shows a decrease in water absorption rate after the treatment.

scholarly journals Physical and mechanical properties of mortars containing date palm fibers

2022 ◽  
Author(s):  
Saleh Bamaga
Keyword(s):  
Mechanical Properties ◽  
Compressive Strength ◽  
Water Absorption ◽  
Absorption Rate ◽  
Date Palm ◽  
Physical And Mechanical Properties ◽  
Water Absorption Rate ◽  
Date Palm Fibers ◽  
Rate Test ◽  
Construction Works

Abstract This paper presents the results of a study conducted to investigate the effects of incorporating Sefri Date Palm Leave Fibers (SDPLF) into the mortar. A total of seven mixtures were prepared and tested. SDPLF were collected from local farms. The fibers were then cleaned, dried, and cut to different sizes of 10 mm, 20 mm, and 50 mm, maintaining the same individual fiber width of approximately 5±2 mm. The content of SDPLF in mortars was kept to 1% and 3% by mass. The physical and mechanical properties of SDPLF fibers and SDPLF mortars were investigated. The compressive strength at 7, 14, and 28 days was determined. The water absorption rate test was carried out on mortars containing 1% SDPLF fibers. The results showed that mortars with SDPLF have lower workability, lower density, and lower compressive strength as compared to control mortars. However, they are still acceptable for use in construction works. Mortars containing 10 mm and 20 mm SDPLF fibers by mass showed significant improvement in terms of water absorption rate as compared to the control mortar.

Effect of Water Absorption on Mechanical Properties of Hemp Fiber Reinforced Composite

2009 ◽  
Vol 417-418 ◽  
pp. 161-164 ◽  
Author(s):  
Kenichi Takemura
Keyword(s):  
Mechanical Properties ◽  
Water Absorption ◽  
Absorption Rate ◽  
Strength Reduction ◽  
Fiber Content ◽  
Hemp Fiber ◽  
Absorption Time ◽  
Dry Process ◽  
Water Absorption Rate ◽  
Effect Of Water

In this study, the effect of water absorption on mechanical properties of hemp fiber reinforced green composite(HGC) was examined. Plain woven hemp fabric was used as reinforcement. Emulsion type biodegradable resin was used as matrix. The composite was made by compression molding method. Water absorption rate and the effect of the ratio on the mechanical properties were examined. Following results are obtained. The water absorption rate increased with an increase of absorption time. The water absorption rate had an equilibrium state within 30 days. The duration was not dependent on fiber content. In the case of that specimen was kept in water 182 days, the strength decreased 70% of the ultimate one. But in the case that the specimen has dry process after water absorption process, the strength recovered 57%. The recovery ratio is not dependent on water absorption time. The strength reduction rate after dry process is not dependent on fiber content. The strength of resin decreased 62%, and the strength of fiber decreased 13% by water absorption. So the strength reduction of the composite is due to the effect of matrix.

scholarly journals Moisture Absorption Behavior and Adhesion Properties of GNP/Epoxy Nanocomposite Adhesives

Polymers ◽  
2021 ◽  
Vol 13 (11) ◽  
pp. 1850
Author(s):  
Nurziana Kong ◽  
Nur Zalikha Khalil ◽  
Holger Fricke
Keyword(s):  
Mechanical Properties ◽  
Shear Strength ◽  
Water Absorption ◽  
Water Uptake ◽  
Absorption Rate ◽  
Adhesive Bonding ◽  
Moisture Absorption ◽  
Adhesion Properties ◽  
Water Absorption Rate ◽  
Immersion Period

In the current work, an attempt has been made to investigate the effect of Graphene Nanoplatelets (GNP) reinforcement to water absorption behavior and mechanical properties of adhesive bonding with epoxy. Epoxy adhesive with various GNP content (i.e., 0.0~2.0 wt%) was utilized to joint aluminum adherend subjected to various immersion periods (i.e., 0~60 days). Subsequently, the effect of GNP reinforcement on water uptake, water absorption rate and tensile shear strength was investigated. Depending on GNP content, two distinct behaviors in water uptake and moisture absorption rate have been observed; specimens with lower GNP content (0.5~1.0 wt%) have demonstrated increased/retention of water uptake and water absorption rate regardless of immersion period. Meanwhile, at higher GNP content (1.5~2.0 wt%), decreased water uptake and water absorption rate are generally observed. At similar GNP content, regardless of immersion periods, water immersed specimens generally demonstrate higher or retention of shear strength when compared to specimens at 0-day immersion period. These observations suggest that the relation between moisture absorption behavior and mechanical properties of GNP-reinforced adhesive with GNP content are rather complex which might be attributed to the interplay of several possible mechanisms.

Sulphate-Based Flame-Retardant for Handmade Mulberry Paper

2008 ◽  
Vol 55-57 ◽  
pp. 833-836 ◽  
Author(s):  
W. Naksata ◽  
Manoch Naksata
Keyword(s):  
Mechanical Properties ◽  
Water Absorption ◽  
Flame Retardant ◽  
Young’S Modulus ◽  
Ammonium Sulphate ◽  
Flame Retardants ◽  
Absorption Rate ◽  
Flash Point ◽  
Water Absorption Rate ◽  
Mulberry Paper

Handmade mulberry paper was coated with flame retardants reagent: ammonium sulphate, at the various concentrations. The properties of mulberry paper, i.e. rate of water absorption, rate of flammability, flash point and mechanical properties expressed as Young’s modulus were studied. Mulberry paper coated with sulphate-based compound was not flammable and the rate of water absorption was decreased, while the elasticity was increased.

Influence of Polymer on Properties of Sulphoaluminate Cement Waterproof Mortar

2015 ◽  
Vol 740 ◽  
pp. 43-46 ◽  
Author(s):  
Wen Hong Tao ◽  
Bin Wu ◽  
Xing Hua Fu ◽  
Chuang Liu
Keyword(s):  
Mechanical Properties ◽  
Water Absorption ◽  
Absorption Rate ◽  
Cement Mortar ◽  
Cellulose Ether ◽  
Sulphoaluminate Cement ◽  
Water Absorption Rate ◽  
Early Strength ◽  
Better Than

This paper studies on the effects of different contents of redispersible emulsion powder and cellulose ether on mechanical properties of sulphoaluminate cement waterproof mortar, water absorption rate and impermeability, observes the microstructure of cement mortar by SEM and discusses the mechanism of polymer effects on properties of cement mortar. The results show that: as to the influence on strength, the two kinds of polymers may cause the decrease of early strength, but have no influence on the later strength; about water absorption rate, two polymers can significantly reduce the water absorption rate of sulphoaluminate cement mortar, and cellulose ether is slightly more effective than that of redispersible emulsion powder; as to the influence on impermeability, cellulose ether works far better than redispersible emulsion powder, especially when cellulose ether content reaches 1.5‰ and more, the impermeability pressure of sulphoaluminate cement mortar can reach above 2.2MPa.

scholarly journals Preliminary Study of Oil Palm Decanter Cake Natural Polymer Composite (OPDC-NPC)

2014 ◽  
Vol 911 ◽  
pp. 40-44 ◽  
Author(s):  
Muhammad Aqif Adam ◽  
Alawi Sulaiman ◽  
Che Mohd Som Said ◽  
Ayub M. Som ◽  
Azhari Samsu Bahruddin ◽  
...  
Keyword(s):  
Tensile Strength ◽  
Water Absorption ◽  
Polymer Composite ◽  
Palm Oil ◽  
Oil Palm ◽  
Absorption Rate ◽  
Natural Fiber ◽  
Natural Polymer ◽  
Water Absorption Rate ◽  
Decanter Cake

Palm oil industry produces huge amount of oil palm decanter cake (OPDC). Currently it is not yet commercialized however due to its characteristics, it can be used to produce oil palm decanter cake natural polymer composite (OPDC-NPC). NPC is a type of material made by combining natural fiber with polymer. Therefore the objective of this paper is to produce NPC from OPDC and then determine its mechanical and physical properties such as elasticity, stiffness, tensile strength and water absorption rate. The OPDC samples were collected from Felda Trolak Palm Oil Mill. Prior to NPC development, the oil was removed from OPDC using hexane soxhlet extraction method. OPDC-NPC was fabricated using molding method where the mixture of 95% polypropylene (PP) and 5% OPDC were mixed using twin-screw extruder. The results showed that OPDC-NPC has an elasticity of 2231 MPa, stiffness of 30 MPa, tensile strength of 32 MPa and water absorption rate of 0.16 % which was slightly better with the other types of fibers.

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