Durability of Concrete Containing PFA-GGBS By-products

Ground Granulated Blast-furnace Slag (GGBS) and Pulverised Fuel Ash (PFA) were used to replace up to 60% of Portland cement (PC) in concrete. The testing program of the concrete included the determination of the consistency of fresh concrete, the measurement of the density and compressive strength of the hardened products cured for up to 56 days and the evaluation of their durability via visual inspections and strength loss calculations after the freeze and thaw cycles. The results showed that the blend proportion and type had affected the consistency of the fresh concrete. Replacing the PC with 20% for PFA or 40% for GGBS had similar performances as the control mix. The durability of concrete subject to freeze and thaw had little effect on the concrete specimens. It was observed that the concrete without blends suffered the worst, resulting in chips along the edges of the cube and scaling of the faces compared to mixes with 20% GGBS and 20% PFA which resulted in increased durability. However, blended concrete exhibited more loss in strength compared to the concrete without cement blends.

An Analysis of Quality Characteristics of Bamboo/Cotton Blended Yarns of Rotor and Ring Spun

Denim fabrics are in general manufactured by using 100% cotton fibers. A novel attempt has been made by using bamboo/cotton yarns in warp and weft directions to produce denim fabrics using ring yarns in warp and rotor yarns in weft directions. In this research work, bamboo/cotton yarns are manufactured in different blend compositions like 100% bamboo, 100% cotton,70:30, 50:50 and 30:70 ratios. Ne 10 and Ne 16 carded yarns are manufactured from both the ring and rotor spinning systems. The yarns manufactured out of these two spinning systems have been critically analyzed for their quality characteristics like Unevenness, Imperfections, Hairiness, friction, abrasion, strength and elongation. The influence of blend ratios on yarn quality characteristics in ring and rotor yarns has been analyzed and the optimum blend proportion which gives the best quality has been investigated.

Influence of the Bamboo/Cotton Fibre Blend Proportion on the Thermal Comfort Properties of Single Jersey Knitted Fabrics

The main aim was to find out the influence of the blend ratio and linear density on the thermal comfort properties of regenerated bamboo cotton blended single jersey knitted fabrics. An increase in the regenerated bamboo fibre ratio in the fabric influences the thermal comfort properties. Knitted fabrics prepared from regenerated bamboo blended yarns have lesser thickness and inferior mass per square meter than cotton fabrics. The proportion of regenerated bamboo fibre increases in the yarn as the value of thermal conductivity decreases in knitted fabrics. Water vapour permeability and air permeability confirm a similar increase as the proportion of regenerated bamboo fibre increases. 100% regenerated bamboo fabrics have superior air permeability values compared with regenerated bamboo/cotton blended fabrics. The statistical investigation also showed that the results are significant for the thermal comfort properties of regenerated bamboo cotton knitted fabrics.