Effect of coir geotextile and geocell on ephemeral gully erosion in the Mollisol region of Northeast China

The unique geomorphological features and farming methods in the Mollisol region of Northeast China increase water catchment flow and aggravate the erosion of ephemeral gully(EG).Vegetation suffers from rain erosion and damage during the growth stage,which brings serious problems to the restoration of grass in the early stage.Therefore,effects of coir geotextile and geocell on EG erosion under four confluence intensities were researched in this study.Results of the simulated water discharge erosion test showed that when the confluence strength was less than 30 L/min,geocell and coir geotextile had a good effect on controlling EG erosion,and sediment yield of geocell and coir geotextile was reduced by 25.95%–37.82%and 73.73%–88.96%,respectively.However,when confluence intensity increased to 40 L/min,protective effect of coir geotextile decreased,and sediment yield rate increased sharply by 189.03%.When confluence intensity increased to 50 L/min,the protective effect of coir geotextile was lost.On the other hand,geocell showed that the greater the flow rate,the better the protective effect.In addition,with the increase in confluence intensity,erosion pattern of coir geotextile developed from sheet erosion to intermittent fall and then to completion of main rill,and the protective effect was gradually weakened.In contrast,the protective effect of EG under geocell was gradually enhanced from the continuous rill to the intermittent rill and finally to the intermittent fall.This study shows that coir geotextile and geocell can prevent EG erosion,and the effect of geocell is better than that of coir geotextile on the surface of EG.

Performance evaluation of laterite soil embankment stabilized with bottom ash,coir fiber,and lime

In tropical regions,heavy rainfall induces erosion and shallow landslides on road embankments.Cement-based stabilization methods,common in these regions,contribute to climate change due to their high carbon footprint.This study explored the potential application of coir fiber-reinforced laterite soil-bottom ash mixtures as embankment materials in the tropics.The objective is to enhance engineered embankment slopes'erosion resistance and stability while offering reuse options for industrial byproducts.This study examined various mix designs for unconfined compressive strength(UCS)and permeability,utilizing 30%bottom ash(BA)and 1%coir fiber(CF)with varying sizes ranging from 10 to 40 mm,6%lime,and laterite soil(LS),followed by microstructural analyses.The results demonstrate that the compressive strength increases as the CF length increases to 25 mm.In contrast,permeability increases continuously with increasing CF length.Lime-treated mixtures exhibit superior short-and long-term strength and reduce permeability owing to the formation of cementitious materials,as confirmed by microstructural analyses.A lab-scale slope box was constructed to evaluate the surface erosion of the stabilized laterite soil embankment.Based on the rainfall simulation results,the LS-BA-CF mixtures show better resistance to erosion and deformation compared to untreated LS,especially when lime is added to the top layer.This study provides insights into a sustainable and cost-effective approach for slope stabilization using BA and CF,offering a promising solution for tropical regions susceptible to surface erosion and landslides.

A Model Study on Accelerated Consolidation of Coir Reinforced Lateritic Lithomarge Soil Blends with Vertical Sand Drains for Pavement Foundations

Sub-grade soils of lateritic origin encountered in the construction of highway embankments in various regions of India, often comprise intrusions of soft lithomargic soils that result in large settlements during constructions, and differential settlements at later stages. This necessitates the use of appropriate soil improvement techniques to improve the load-carrying capacity of pavements. This work deals with accelerated consolidation of un-reinforced and coir-rein- forced lateritic lithomargic soil blends, provided with three vertical sand drains. The load-settlement characteristics were studied for various preloads ranging from 50 kg (0.0013 N/mm2) to 500 kg (0.013N/mm2) on soil specimens prepared in circular ferro-cement moulds. It was observed that at lower preloads up to 200kg, across the blends, the relative increase in consolidation (Rct) for randomly reinforced soil with vertical drains was sig-nificantly higher than that of un-reinforced soil without vertical drains, with an average value of 124.8%. Also, the Rct for un-reinforced soil with vertical drains was quite higher than that of un-reinforced soil without vertical drains, with an average value of 103.9%. In the case of higher preloads, the Rct values for randomly reinforced soil with vertical drains were moderate with an average value of 30.88%, while the same for un-reinforced soil with vertical drains was about 20.4%. The aspect-ratio of coir fibers used was 1:275.

Aqueous Lead Removal under Optimized Conditions Using Phosphoric Acid Activated Coconut Coir Activated Carbon

The global burden of heavy metal environmental pollution remains one of the most challenging issues to be addressed urgently. Lead (Pb) has been well recognized as a toxic environmental pollutant. The main objective of this study was to examine the adsorption efficiency of phosphoric activated coconut coir activated carbon for lead (II) removal from an aqueous solution. Synthesized activated carbon was characterized before and after the adsorption of Pb(II) by powder X-Ray diffraction, Fourier transforms infrared spectroscopy and scanning electron microscopy coupled with energy dispersive X-Ray. Furthermore, the removal efficiency of Pb(II) of synthesized activated carbon was tested with different concentrations of Pb(II) solutions, pH levels, adsorbent dosages, and contact time. Atomic absorption spectroscopy was used to analyze the Pb(II) concentrations in water samples. The maximum Pb(II) removal percentage of 100% was obtained with 50 mL of 5 mg/L Pd(II) ion solution and 0.20 g of the synthesized activated carbon. Adsorption data were well fitted with the Freundlich adsorption isotherm model, and adsorption kinetics were fitted with the pseudo-second-order kinetic model with R2 of 0.99. These results conclude that the synthesized activated carbon can be used as a potential sorbent for the removal of lead from wastewaters.

Evaluation of Mechanical and Physical Properties of Pressed Coir Fiber/Epoxy Composite with NaOH and Microwave Treatment of Fiber

In this study,the influence of sodium hydroxide(NaOH)treatment and microwave treatment of coir fibers on the mechanical and physical properties of pressed coir fiber/epoxy composite were evaluated.The composite was fabricated with a hand lay-up method with compression molding.Before composite fabrication,pressed coir fiber was treated with NaOH and microwave treatments.Mechanical testing(tensile,flexural,and impact testing)of the composite was conducted.Then,water absorption and thickness swelling testing are also performed.The fractured composite surface morphology after the tensile test was analyzed by scanning electronic microscopy(SEM).The results revealed that tensile,flexural,and impact strengths of composite tend to increase after NaOH treatment of coir fiber followed by microwave treatment for 10 and 20 minutes of exposure time compared to untreated fiber.However,for NaOH treatment,the tensile,flexural and,impact strengths of composite reduce.The reducing of the tensile strength of the composite is due to the agglomeration fiber occurred,which is displayed in the SEM micrograph.Furthermore,microwave treatment of fiber for 10 minutes and NaOH treatment followed by microwave treatment for 20 minutes of exposure time decreases the water absorption and thickness swelling of the composite.

Dynamic Behaviour of Pond Ash Mixed with Coir and Crumb Rubber

An experimental program was conducted to determine the dynamic properties of pond ash(PA)and pond ash mixed with admixtures like crumb rubber(CR)and coir fiber(CF)which are wastes of different industries.Additives CR and CF were mixed separately with pond ash in a percentage ranging from 0%–20%at an interval of 5%and 0%–2%at an interval of 0.5%by weight of pond ash,respectively.Dynamic properties(Shear modulus,Number of cycles to initiate liquefaction,Degradation index and Damping ratio)for pond ash mixes were determined using strain-controlled cyclic tri-axial apparatus.The shear strain was kept constant at 1.2%and the frequency varied from 0.4 to 1 Hz.Liquefaction resistance improves when crumb rubber is added to pond ash,however adding Coir fiber to pond ash has essentially no effect on the number of cycles required to initiate liquefaction.The dynamic shear modulus decreases when crumb rubber was mixed in pond ash whereas when coir fiber is added to pond ash,the dynamic shear modulus increases significantly.A mix of PA,CR,and CF was also tried to balance the number of cycles required to initiate liquefaction and shear modulus.The mixed sample in the proportion of PA(84%)+CR(15)+CF(1%)can be termed a balanced mix as the number of cycles to initiate liquefaction was more than all PA-CF mixes and also the shear modulus was more than all PA-CR mixes.Damping ratio increases with increasing frequency of loading(0.4 to 1 Hz).

Crystallization and Dynamic Mechanical Behavior of Coir Fiber Reinforced Poly(Butylene Succinate)Biocomposites

The crystallization behavior,crystal morphology and form,and viscoelastic behavior of poly(butylene succinate)(PBS)and coir fiber/PBS composites(CPB)were investigated by differential scanning calorimetry(DSC),polarized optical microscopy(POM),X-ray diffraction(XRD)and dynamic mechanical analysis(DMA).The results of DSC measurement show that the crystallization temperature increases with the filling of coir fibers.POM images reveal that the spherulitic size and crystallization behavior of PBS are influenced by the coir fibers in the composites.XRD curves show that the crystal form of pure PBS and CPB are remaining almost identical.In addition,the storage modulus of CPB significantly increases comparing with the pure PBS.This predicted the dimensional stability and improved load-deformation temperature.In conclusion,the addition of coir fibers has a significant effect on the thermal properties of the matrix.

Optimization of Mortar Compressive Strength Prepared with Waste Glass Aggregate and Coir Fiber Addition Using Response Surface Methodology

Waste Glass(WGs)and Coir Fiber(CF)are not widely utilized,even though their silica and cellulose content can be used to create construction materials.This study aimed to optimize mortar compressive strength using Response Surface Methodology(RSM).The Central Composite Design(CCD)was applied to determine the optimization of WGs and CF addition to the mortar compressive strength.Compressive strength and microstructure testing with Scanning Electron Microscope(SEM),Fourier-transform Infrared Spectroscopy(FT-IR),and X-Ray Diffraction(XRD)were conducted to specify the mechanical ability and bonding between the matrix,CF,and WGs.The results showed that the chemical treatment of CF produced 49.15%cellulose,with an average particle size of 1521μm.The regression of a second-order polynomial model yielded an optimum composition consisting of 12.776%WGs and 2.344%CF with a predicted compressive strength of 19.1023 MPa.C-S-H gels were identified in the mortars due to the dissolving of SiO_(2) in WGs and cement.The silica from WGs increased the C-S-H phase.CF plays a role in preventing,bridging,and branching micro-cracks before reaching maximum stress.WGs aggregates and chemically treated CF are suitable to be composited in mortar to increase compressive strength.

Research on the Geometry and Microstructure of the Coir Fiber

Coir fiber is derived from the coconut shells and considered to be an economical and natural material. In order to further extend its application fields,the geometry and microstructure of the coir fiber were thoroughly investigated in this research. The single fiber length measurement was carried out,and it was revealed that the length of the coir fiber was between 8 and 337 mm. Length distribution of the coir fiber was simulated by using the computer technology,and was found to be in coincidence with that of most natural fibers. The grouping measurement analysis was used to study the length-weight distribution and length-linear density distribution of the fiber. It was found that the average linear density was 27.89 tex and the linear density was between 18.265 and 70.442 tex. The length-weight distribution of the coir fiber showed a Poisson pattern,and the weight of fibers with the length between 50 and 230 mm accounted for 85.28% of the total fibers measured. In this research,scanning electron microscope (SEM) was applied to observe the morphological changes of coir fiber before and after alkali treatment;and the result shows that alkali treatment leads to the removal of lignin and pectin from both the cuticle and the inside walls,which is beneficial for the interfacial adhesion with polymer matrix in composite fabrication.

Evaluation and Optimization of Tensile Strength Responses of Coir Fibres Reinforced Polyester Matrix Composites (CFRP) Using Taguchi Robust Design

In this study, control factors which included aspect ratio of fibres, volume fraction of fibres and fibres orientation were the focus for determining the optimum tensile strengths of coir fibres reinforced polyester resin composites. After using Archimedes principle to determine the volume fraction of fibres, tensile test was conducted on the samples of treated and untreated coir fibres reinforced polyester resin composites, respectively. For the optimum properties to be obtained, a Universal Testing Machine-TUE-C-100 was used for the conducted tensile tests which established the levels of control factors settings for quality characteristics needed to optimize the mechanical properties being investigated. Applying Taguchi robust design technique for the greater-the-better, the highest signal-to-noise ratio (S/N ratio) for the quality characteristics being investigated was obtained employing Minitab 16 software. The optimum values of the control factors were established for treated coir fibres reinforced polyester resin composites and untreated coir fibres reinforced polyester resin composites. The treated coir fibres reinforced polyester matrix composite has the optimum tensile strength of 42.7 N/mm2 while the untreated coir fibres reinforced matrix composite has the optimum tensile strength of 21.9 N/mm2. The reinforcement combinations of control factors contribute greatly to the tensile properties, and the treated coir fibres reinforced polyester composites are stronger in tension than the untreated coir fibres reinforced polyester composites.

Biochemical changes during composting of coir pith waste as influenced by different agro industrial wastes

Coir pith, a byproduct of coconut husk is difficult to decompose due to its high lignin and cellulose content. In this study, coir pith was composted with different agro industrial by products such as cow dung, vegetable market waste, poultry waste and microbial consortium. The different treatment combinations used in the present study were Control, T1 (Coir pith + Cow dung + Vegetable market waste + Poultry waste + mixed microbial culture (Trichoderma viridae + Pleurotus sajar caju), T2 (Coir pith + Vegetable market waste + Poultry waste + Tank slit + Mixed microbial culture) and T3 (Coir pith + Cow dung + poultry waste + tank slit + mixed microbial culture). At the end of 12th week, in the treatment T1, C: N ratio of 21.8:1 was observed in the composted coir pith sample. Highest P content of 0.47% and K content of 1.2% and the least Cellulose and Lignin contents of 22.8% and 10.03% were recorded in the T1 treatment after a composting period of 12 weeks. Highest pH of 7.4 was observed in the treatment T3, this was followed by T1 (7.2) treatment.

Some Effect of Chemical Treatment by Ferric Nitrate Salts on the Structure and Morphology of Coir Fibre Composites

The present study shows some important effects of chemical treatment on the structure and morphology of coir fibre. The objective of the present study is to optimise overall properties of coir fibre so as to use coir fibre as a reinforcing agent in thermoplastic and thermosetting polymers. In the present study, coir fibre is treated with ferric nitrate salt. A thermal treatment has been done at temperature of 1000&degC by using annealing method. X-ray diffraction of the treated coir fibre reveals the crystalline nature of the fibre. Change in morphology has been found in coir fibre when subjected to scanning electron microscopy. Finally, the Fourier transform and infrared spectrographs show the presence of traces of iron oxide:fibre in the prepared composite.

Comparative Study of Physical Properties of Polymer Composites Reinforced with Uncarbonised and Carbonised Coir

This study involved the use of uncarbonised and carbonised coir in preparing composites of a given polymer. In this case natural rubber (NR) was used. Uncarbonised coir (UC) and carbonised coir (CC) were separately used to prepare the polymer composites. Carbon black (CB) was also used differently and the filler loadings for all varied between 0 and 50 phr. Before using the uncarbonised coir and carbonised coir, they were characterised on the basis of moisture content, pH, particles size and surface area. The properties of the various composite samples prepared were then investigated. The results of the tests obtained for the NR-UC composites were compared with those of NR-CC and also with those of NR-CB composites. It was observed that for hardness, the results obtained from composites of UC and CC fillers showed similar trends with those of carbon black (CB) reinforced composites, increasing with increase in filler volume. For the tensile strength and modulus a trend of slight rise was observed. There were no sharp rises in values as filler volumes were increased. UC and CC fillers were observed to impart very poorly on the tensile strength and modulus relative to the CB reinforced composites. The results from test for elongation, compression set and flex fatigue showed a falling trend for all the fillers to a comparable level with CB. It was generally observed that the uncarbonised coir presented better potentials for reinforcement than the carbonised coir.

Load Settlement Characteristics of Model Footings Resting on Surface Treated Coir Fiber Reinforced BC Soil Overlying Loose Stratum

In nature there are situations where in foundation had to be placed over loose soil deposits. In such cases, deep foundations are recommended which increases cost of the structure. Black cotton soils, because of its high swelling and shrinkage characteristics, have been a challenge to geotechnical engineers, increasing the strength of Clayey soil which is formed introducing randomly distributed fibers results in comparatively more homogeneous soil mixture and is one of the popular methods of soil stabilization. In the present study, model footing resting on BC soil reinforced with optimum percentage of treated and untreated coir fiber underlain by loose soil deposit was conducted to study its influence on bearing capacity and settlement. Loose soil deposit has been simulated by compacting sawdust in prefabricated steel tank. BC soil reinforced with optimum percentage of treated and untreated coir fibers has been compacted over loose sawdust and load settlement characteristics were determined at various D/B ratio of 1,2, 3 and for different sized model footings. The results indicated that settlement of model footings is significantly small at lower D/B = 1 and 2 ratios. Bearing capacity of BC soil is also found to be significantly affected by fiber reinforcement.

EXPERIMENTAL STUDY OF ACOUSTICAL INSULATION OF CEMENT-BASED BOARD PREPARED WITH WASTE COCONUT COIR AND OIL PALM FIBERS

Among the major challenges facing the modern era of technological and industrial advancements are pollution and exponentially growing energy consumption.Pollution continues to be a menace affecting different aspects of life such as health,productivity,and comfort.This paper focuses on the elimination or reduction of sound pollution in buildings using cement-based boards made from pretreated coconut coir and oil palm fibers obtained from agricultural residues.The study includes an account of the preparation of fiber cement boards made from Portland cement Type 1,limestone powder,water,sand,and pretreated coconut coir and oil palm fibers at 5,10,15,and 20%by weight of powder materials,respectively,and a high-range water reducer in order to make sure that the natural materials would be spread in an even way throughout the specimens.Sound insulation tests were performed as key indicators of the performance of the fiber cement boards.It was found that an increase in the proportion of natural materials resulted in fiber cement boards with decreased density,compressive strength,and flexural strength.Furthermore,in relation to both physical and mechanical performance,the boards incorporating coconut fibers were superior to those incorporating oil palm fibers.With an increased proportion of natural fibers,sound insulation performance tended to improve.The boards prepared with coconut coir and oil palm fibers in this study yielded acceptable physical and mechanical properties and showed promise in relation to providing insulative protection against sound.

Effect of drying-wetting cycles on the durability of calcareous sand reinforced by MICP and recycled shredded coconut coir(RSC)

Microbial-induced carbonate precipitation(MICP)technique has been adopted in geotechnical engineering widely.In this study,the effect of drying-wetting cycles on MICP-recycled shredded coconut coir(RSC)reinforced calcareous sand was studied,and the deterioration mechanism under drying-wetting cycles was revealed.Test results indicated that drying-wetting cycles exert an important influence on the durability of MICP-RSC reinforced specimens.With the increase of drying-wetting cycles N,the specimens demonstrated significant increase in mass loss rate and critical void ratio,decrease in maximum shear modulus,peak strength and toughness.Furthermore,an increase in the initial relative density reduced the deterioration of MICP-RSC reinforced specimens exposed to drying-wetting cycles.Higher initial relative density of the specimen correlates with an increased maximum shear modulus,peak stress and toughness,a decreased in permeability and critical void ratio.Microanalysis revealed that the generated calcium carbonate adhering to sand particles and RSC gradually dropped off with the increase of N,weakened cementation,and led to the deterioration of MICP-RSC reinforced specimens,which is consistent with the deterioration characteristics under drying-wetting cycles.

Flexural and Dynamic Mechanical Properties of Alkali-Treated Coir/Pineapple Leaf Fibres Reinforced Polylactic Acid Hybrid Biocomposites

Polylactic acid(PLA)possesses good mechanical and biodegradability properties which make it a suitable material for polymer composites whereas brittleness and high costs limit its utilization in various applications.The reinforcement of natural fibres with biopolymers has been formed to be an efficient technique to develop composites having the ability to be fully biodegradable.This study concerns with the incorporation of various percentages of untreated and alkali-treated Coir Fibres(CF)and pineapple leaf fibres(PALF)in PLA biocomposites and characterizations of flexural,morphological and dynamic mechanical properties.Flexural properties showed that the treated C1P1 hybrid composites(C1P1A)displayed highest flexural strength(35.81 MPa)and modulus(5.28 GPa)among all hybrid biocomposites.Scanning Electron Microscopy(SEM)revealed a behaviour of fibre-matrix adhesion in untreated treated biocomposites.SEM observation revealed good dispersion of the fillers in PLA.Dynamic mechanical analysis revealed that C1P1A showed highest glass transition temperature(Tg)and storage modulus(E')while untreated C3P7 displayed the least Tg and E'.Overall findings showed that alkali-treated hybrid biocomposites(CF/PALF/PLA)especially C1P1A have improved flexural properties,dynamic and morphological properties over untreated biocomposites.Success of these findings will provide attracting consideration of these hybrid biocomposites for various lightweight uses in a broad selection of industrial applications such as biomedical sectors,automobile,construction,electronics equipment,and hardware tools.

Lignin and holocellulose from coir pith involved in trimethylamine(fishy odor) adsorption

Coir pith is a highly potential adsorbent for adsorbing trimethylamine(TMA). It harbors a higher adsorption capacity for TMA compared to commercial activated carbon(CAC). It was found that lignin and holocellulose extracted from coir pith played an important role in TMA adsorption. Lignin itself had the highest TMA adsorption capacity(269.01 mg/g)followed by holocellulose(75.43 mg/g), coir pith(14.3 mg/g) and CAC(10.26 mg/g),respectively. The pseudo-first-and second orders were applied to the kinetic data. For the adsorption of TMA by coir pith, the best fit was achieved by the pseudo-second order.Thermodynamic studies showed an endothermic and physico-chemical adsorption process between TMA and the coir pith. TMA desorption study suggested that only 14%–47% of TMA was desorbed with distilled water. In addition, Fourier transform-infrared(FT-IR) spectra showed that C–H bond(methyl group), C–O bond from phenolic alcohol and C–O bond from tertiary alcohol in lignin and holocellulose were involved in TMA adsorption. Coir pithbased filter showed high TMA adsorption efficiency(98%) and kept constant for more than48 days in a continuous system. Pilot scale experiment, coir pith beads filter could be succesfully applied as a packing material for TMA removal. Therefore, coir pith can be used as a promising packing material for TMA treatment at contaminated site.

Effect of Filler Content on Flexural and Viscoelastic Properties of Coir Fibers and Argania Nut-shells Reinforced Phenolic Resin Composites

The characteristics of two different kinds of lignocellulosic materials(vegetable fillers)with two morphologies as Argania nut-shells(ANS)particles and Coir Fibers(CF)were used as reinforcement for phenolic resin(Bakelite)in this work,and the composite are studied as a function of filler types,shape,content(10,20,and 30%wt.percent)and manufacturing loading force(1500 and 3000 LBs).Compression molding was used to create the composites,which were then evaluated using Scanning electronic microscopy(SEM),Fourier-transform infrared spectroscopy(FTIR),bending,dynamic-mechanical-thermal and rheological studies.The morphology of broken samples demonstrates that both fillers are well dispersed and distributed.When fillers are added to the matrix,the flexural characteristics improve,and the optimal values are attained in the case of Argania nut-shells.The results showed that the kind and shape of the fillers had a direct influence on the dynamic mechanical characteristics of the composites due to the reinforcement's modulus augmentation.It was noticed that,the increment of manufacturing loading force decreased the mechanical and dynamical properties of composites.The optimum properties obtained indicate that the composites can only be manufactured at low manufacturing loading force(1500 LBs).

椰壳纤维加筋土遗址生态注浆材料的性能

为提升土遗址注浆料的力学性能,以椰壳纤维掺和糯米浆、烧料礓石以及黄土改性注浆料为研究对象,研究了椰壳纤维长度和掺量(质量分数)对土遗址注浆料流动性、收缩性、抗压强度和抗折强度的影响.结果表明:椰壳纤维的掺量和长度越大,浆体的流动性越低,而椰壳纤维的长度与浆体的收缩率无明显相关性;椰壳纤维良好的桥接能力可以有效提高浆体固化后的抗压强度、抗折强度和延性;椰壳纤维的长度和掺量均存在最优值,建议最优配比为纤维长度6 mm、掺量0.5%~0.6%,此时浆体固化后的抗压强度、抗折强度分别提升49.09%和32.08%;过多、过长的椰壳纤维易发生弯折、团聚,导致浆体的流动性和强度大幅降低.