The influence of Modal–cotton (MC) fibre blend ratio and ring frame machine parameters such as front top roller loading and break draft on the blended yarn properties has been studied. Compact MC blended yarn samples of 14.75 tex with three different MC fibre blend ratio has been produced in a LR 6 ring spinning frame fitted with Suessen Compact drafting system. A robust design optimisation to minimise the variations of the output yarn properties such as blended yarn tenacity, yarn unevenness and hairiness caused because of the variations in the material as well as machine setting parameters is achieved through the Taguchi parametric design approach. It is found that the maximum compact MC blended yarn tenacity is 23.76 g/tex, which is influenced very much by MC fibre blend ratio but meagrely by top roller loading and break draft. Similarly, the minimum 9.54 U% and 3.59 hairiness index are achieved with 100:0 and 70:30 MC fibre blend ratio, respectively, at 23-kg top roller loading. Statistical ANOVA analysis is performed on the results and optimum values are obtained within the 95% confidential level through confirmation experiments.
Nano technology is an emerging field of interest for civil engineering application. Among the nano materials presently used in concrete, nano-silica possess more pozzolanic nature. It has the capability to react with the free lime during the cement hydration and forms additional C-S-H gel giving strength, impermeability and durability to concrete. Present paper investigates the effects of addition of nano silica in normal strength concrete. Three types of nano-silica in the form of nano suspension having different amount of silica content have been investigated. Mix design has been carried out by using particle packing method. X-Ray diffraction (XRD) analysis has been carried out to find the chemical composition of control concrete and nano modified concrete. Further, experimental investigations have been carried out to characterize the mechanical behaviour in compression, tension and flexure. It has been observed that the addition of nano-silica in normal strength concrete increased the compressive strength and decreased the spilt tensile strength and flexural strength. Also, Rapid chloride permeability test (RCPT) has been conducted to know the chloride permeability of control concrete, nano modified concrete, and nano coated concrete. It has been observed that the chloride permeability is less for nano coated concrete.