This paper reports the frictional properties of a series of siro spun yarns produced from cotton, polyester/cotton, and viscose. The coefficient of friction of the yarns has been measured using Howell's method where the two yams slide against each other at right angles. Yarn-to-metal friction has also been measured using a modified version of Howell and Mazur. The dependence of strand spacing and twist on the coefficients of yarn-to-yarn and yarn-to-metal friction has been examined, and the frictional coef ficient increases with increasing strand spacing and twist. The probable reasons for this behavior are discussed in terms of the nature of the yarn surfaces.

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An investigation is reported on the fatigue life of open-end, ring spun, and siro spun yarns using the technique of biaxial rotation over a pin. Open-end yarns have a sig nificantly higher fatigue life compared to ring spun yams. Mercerization increases fatigue life. For siro spun yams, an increase in strand spacing increases the fatigue life in a linear manner. The effect of the twist factor on fatigue life is interesting, in that maximum life is achieved at a twist factor of 40 and thereafter falls. Yarn density and fatigue life seem to be well correlated.

Concrete is one of the most important material that is used in the construction industry all around the world. A larger part of the capacity in concrete is generally employed by the coarse aggregate. Due to the tremendous use of coarse aggregate in the construction industry the material is getting degraded. In order to preserve the natural material, we are in search of an alternate material that can be used in concrete instead of the original one. So in this research work a try has been attempted to study the mechanical behaviour of light weight concrete when we use coarse aggregate as waste coconut shell inside concrete.To improve the strength of concrete we also use the sisal bers in various proportions ranging between 1% to 5% in accordance to the binder weight. After the mechanical properties tests such as the compression test, spilt tensile strength, exural test, modulus of elasticity test, impact resistant test were conducted nally it was concluded that there was increment in the compression strength up to 5%, tensile strength was increased to 17% elastic modulus to 7% when the ber content used was 3%. Thus with the use of these waste materials it was found that the concrete's strength gets increased and it leads to the formation of sustainable concrete thus reducing the pollution in the environment.

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