Flexural characteristics of coir fiber reinforced cementitious composites

This study has examined the flexural properties of natural and chemically modified coir fiber reinforced cementitious composites (CFRCC). Coir fibers of two different average lengths were used, and the longer coir fibers were also treated with a 1 % NaOH solution for comparison. The fibers were combined with cementitious materials and chemical agents (dispersant, defoamer or wetting agent) to form CFRCC. The flexural properties of the composites, including elastic stress, flexural strength, toughness and toughness index, were measured. The effects of fiber treatments, addition of chemical agents and accelerated ageing of composites on the composites’ flexural properties were examined. The results showed that the CFRCC samples were 5–12 % lighter than the conventional mortar, and that the addition of coir fibers improved the flexural strength of the CFRCC materials. Toughness and toughness index, which were associated with the work of fracture, were increased more than ten times. For the alkalized long coir fiber composites, a higher immediate and long-term toughness index was achieved. SEM microstructure images revealed improved physicochemical bonding in the treated CFRCC.

Cement composites reinforced with surface modified coir fibers

An experimental investigation of coir mesh reinforced mortar (CMRM) is conducted using nonwoven coir mesh matting. The main parameters in this study are the fiber volume fraction (number of mesh layers) and fiber surface treatment with a wetting agent. The composites are subjected to the four-point bending test. The short-term mechanical properties of CMRM are discussed. Scanning electron micrograph analysis is used to observe the fiber—matrix interfacial characteristics. The results indicate that the addition of coir mesh to mortar significantly improves the composite post-cracking flexural stress, toughness, ductility, and toughness index, compared to plain mortar materials. The Albatex © FFC wetting agent (2-ethylhexanol) can effectively improve water absorption of coir fiber and enhance the fiber—matrix bonding strength. These coir mesh reinforced composites may be useful in civil engineering applications.

The long-term performance of cementitious composites reinforced with coir fibre

Effective prediction of the long-term performance of natural fibre-reinforced cementitious materials is vital for their application. In this study, coir fibres of two different average lengths were combined with cementitious materials and chemical agents to form coir fibre-reinforced cementitious composites (CFRCCs). The composites long-term performance was assessed and compared with two different accelerated ageing processes, i.e. a cement-saturated water ageing, and alternate freeze-thaw ageing. The flexural properties were compared with the properties of the reference mortar. Overall, the flexural strength of 400 days naturally aged CFRCC specimens was weaker than that of the reference mortar. The toughness and ductility of the fibre-reinforced specimens, however, improved. The cement-saturated water ageing method gave a precise prediction of the flexural strength development of 400-day-old specimens, and the freeze-thaw ageing method worked very well for the toughness performance estimation of CFRCCs.

Effect of different potting media combinations on growth and vase life of tuberose (Polianthes tuberosa Linn.)

The present study was carried out in the agro-metrological conditions of Rawalpindi, Pakistan. Different potting media were used in different combinations to check their effect on the morphological parameters as well as on the vase life of the tuberose. The different treatments included the combinations of FYM, poultry manure, sand, leaf compost and coconut coir in equivalent ratio. The data was analyzed statistically which showed significant effect of media combinations over control values. Maximum plant spread, number of leaves and vase life was recorded in sand+FYM. Coconut coir + FYM contributed to the maximum values of plant height, leaf area and spike length. Maximum plantlets were counted for sand+poultry manure. The highest values of floral diameter, number of flowers per spike and shelf life were observed in sand+leaf compost. These findings lead toward better quality cut flower production with maximum vase life.