K. Gunasekaran

Augmentation of mechanical and bond strength of coconut shell concrete using quarry dust

The properties of concrete using quarry dust (QD) as fine aggregate and coconut shell (CS) as coarse aggregate were examined in this investigation. Workability, density of concrete, compressive, flexural, splitting tensile strengths, impact resistance and bond strength were considered and evaluated with the theoretical values as recommended by IS 456 and BS 8110 standards. For comparison, both conventional and CS concrete mixes are selected with sand and QD have been considered to study. The bond strength was determined as per IS 2770 (Part-I 1987) and ASTM C 234. This study proves that the use of QD in place of sand augmented the mechanical and bond properties of both CSs concrete and conventional concrete as well.

Study on some durability properties of coconut shell concrete with quarry dust

Abstract Quarry dust was used as an alternate material for river sand both in conventional and also in coconut shell concrete. For any materials in concrete to be used in realistic situations, its strength and durability need to be examined. Therefore, this study examines durability performance of quarry dust as fine aggregate and coconut shell as coarse aggregate in concrete. Durability properties investigated include the absorption, volume of permeable voids, sorptivity, rapid chloride penetration test and salt ponding test. Tests were conducted at an age of 3, 7, 28, 56, 90, 180 days and one-year period of curing. The test results showed that the durability properties of quarry dust used concrete performed as a traditional one and coconut shell concrete are comparable to that of other conventional lightweight concretes.

Confining effect by hot rolled steel and cold formed steel on coconut shell concrete with quarry dust

Properties of concrete using quarry dust as fine aggregate and coconut shell as coarse aggregate were examined. Hot rolled and cold formed steel were used as an external confinement on both conventional concrete and coconut shell concrete mixes. Workability, density of concrete, compressive, flexural and impact resistance were considered and evaluated. Uses of quarry dust in place of sand reduce workability and increase density of concretes. In case of without confinement, the compressive strength variation between cubes strength and cylinders strengths are traditional and it is not if it is confined. Flexural specimen with confinement does not fail and stands enough without any sign of failure in case of hot rolled steel. However, in case of cold formed steel, flexural specimen with confinement enhances approximately nine times of the flexural specimen without confinement and stands enough with ductile manner. Hot rolled and cold formed steel confinement effect is not allowing the impact specimen to form crack and in turn not allows failing the specimen. This study proves that the use of quarry dust in place of sand augmented the mechanical properties of both coconut shells concrete and conventional concrete as well. Confinement effect improves promptly the mechanical properties of concretes.