Coir Mat Research Articles

STUDY ON SHEAR STRENGTH CHARACTERISTICS OF COIR MAT REINFORCED SAND

Soil reinforcement technique is one of the most popular techniques used for improvement of poor soils. Metal strips, synthetic geotextiles, geogrid sheets, natural geotextiles, randomly distributed, synthetic and natural fibers are being used as reinforcing materials to soil. Further, the soil reinforcement causes significant improvement in tensile strength, shear strength, other properties, bearing capacity as well as economy. This is a relatively simple technique for ground improvement and has tremendous potential as accost effective solution to many geotechnical problems. The objective of the present investigation is to determine the effect of introducing coir mat reinforced soil layer over soil stratum and effect of size of the opening of coir mat on shear strength characteristics of sand will be analysed.

Comparitive study of Acoustic properties of Weaved Coir Mats

In this paper we report a study on acoustic properties of coir mats –a biofibremat of various weaving patterns. In this study coir-mat has been introduced as one of the sound absorbing materials.There are many advantages of coconut fibres because they are moth-proof,non-hazardous,resistant to fungi and ecofriendly with good sound absorption.The study reveals the effectiveness of coir mats as sound absorber and its applications in building acoustics and automotive applications . Coir mats of different weaving were selected for the study viz;Panama, Herringbone, Boucle weaving,mesh matting,Twill weave matting,Diamond weave matting,PVC tufted mat,Lovers Knot,VC2 mat etc.The experiment is performed on an impedance tube apparatus as per ASTM E 1050/ISO 10534-2. The experimental analysis is made for the frequency range 100 Hz-6300 Hz.The results reveal that the mats show good sound absorption coefficient at high frequencies and also the mats with latex backing and increased thickness exhibit appreciable absorption of coir mats.

Acoustic properties of Composite Coir Mats

In this paper we report the acoustic characterization of coir mats –a biofibremat of various weaving patterns. Being non-hazardous and fully eco friendly with fairly good sound absorption, coir mats are suitable material for acoustic applications for building and automobiles. The study reveals the potential use of coir mats for acoustic absorption purposes. Coir mats of three different weaving were selected for the study viz.Panama, Herringbone and Boucle weaving pattern.The experiment is performed on an impedance tube apparatus as per ASTM E 1050/ISO 10534-2.The effect of latex backing and thickness on absorption coefficient are also studied. The experimental analysis is made for the frequency range 100 Hz-6300 Hz.The results reveals that the mats shows good absorption coefficient at high frequencies and also the mats with latex backing and increased thickness improves the absorption of coir mats.Coating mats with fire resistant material makes it suitable for building acoustics and automobiles.

Impact Toughness Evaluation of Coir Mat Reinforced Unsaturated Polyester Composite

Coir mat reinforced unsaturated polyester composites have been prepared and the impact toughness has been researched, and the impact toughness model has been established based on the coir weight percentage content, the change laws of each mechanical index have been detailed, thus the optimal solutions have been put forward when the coir content was from 10 wt.% to 35 wt.%. The toughening effect of coir mat on unsaturated polyester matrix is remarkable, the non-woven needle mat of coir as the reinforced body for unsaturated polyester matrix is better than that of random distribution coir form.

Absorption and discharge capacity tests on natural prefabricated vertical drains

ABSTRACT: This paper reports absorption and discharge capacity tests conducted in the laboratory on four types of newly developed and fabricated band-shaped prefabricated vertical drain (PVD) made from natural geotextiles and commercially available polymer-based prefabricated vertical drains (PPVDs). The natural PVDs are made from single-layer woven or nonwoven geotextile jute sheath wrapped around a core of coir ropes or coir mats, designated as natural prefabricated vertical drains (NPVDs 1, 2, 3 and 4). Short-term, rubber-membrane-confined discharge capacity tests were conducted at different compressive stresses and hydraulic gradients. The tests were carried out for a better understanding of the influence of NPVD configuration, compressive stress and hydraulic gradient on discharge capacity. The test results for the NPVDs are compared and discussed, together with the results from PPVDs. NPVD 4, which is made of woven jute sheath and corrugated coir mat core, has a greater discharge capacity than the other NPVDs at all the normal stresses and hydraulic gradients studied. The core configuration of NPVD 4 supports the jute sheath better, to prevent it from collapsing into the core as the compressive stress is increased. Although nonwoven jute sheath is a better water-absorbing geotextile than woven jute sheath, the lowest discharge capacity is observed in NPVD 2, which is made from nonwoven jute wrapped around coir ropes. Flow conditions through all the NPVDs are linear at all hydraulic gradients, satisfying the theoretical requirement of PVDs.

English

Reed Canarygrass (RCG) is an exceptionally aggressive invader of wetlands and streambanks throughout much of North America and a serious challenge in many riparian restoration projects. RCG generally degrades habitat quality, can outcompete most native grasses and forbs, and can sometimes invade stream channels. Over the last six years, we have used pre-vegetated coir mats for rapid bank stabilization and native plant establishment and to thwart reinvasion by RCG. In this paper, we use field experiments, case studies, and literature to evaluate whether aggressive revegetation can defeat RCG. Our results demonstrate that: (1) successful revegetation of infested sites is possible; (2) although RCG can be excluded for several years, even sites with very successful revegetation are not immune to reinvasion and may require periodic management; and (3) major hurdles include incomplete initial RCG control and poorly understood or challenging hydrology. Factors that favor RCG over native herbaceous plants include rapid spread by seed and rhizomes, high competitive ability, strong response to nutrients and disturbance, broad hydrologic tolerances, resistance to herbicides and other control practices, presence of non-native genotypes, and historical or continuing use as a forage or for bank stabilization. Complete control and replacement of RCG is unrealistic. Decisions about goals and effort for RCG control will depend on RCG abundance in the landscape, project purpose, project sponsors' values, regulatory context, and mandated performance criteria. Depending on the location and agency, RCG may be treated as a regulated noxious weed, an undesirable invasive plant with low value in rating biological integrity, not a concern, or a plant suitable for pastures and other uses. Where minimizing RCG is required, time and resources should be allocated to pre-project RCG control, analysis of site hydrology, intensive revegetation practices, large woody plant material, follow-up RCG control, and monitoring for at least 3 years.

The influences of different treadmill constructions on ground reaction forces as determined by the use of a force‐measuring horseshoe

SummaryIn the present study, 3 horses trotted at a series of different speeds on a SätoTM treadmill and a coir mat treadmill to determine the differences in ground reaction forces due to the surface of the treadmills. The horses were equipped with a force‐measuring horseshoe to quantify the ground reaction forces which were analysed with spectral analysis. Significant differences between the 2 treadmills were seen in frequency content of the power spectrum for the vertical force at the frequency interval 30–80 Hz and for the fore‐aft force at 30–40 Hz and 70–120 Hz.