Effect of organic binders (corchorus olitorius and abelmoschus esculentus) on the fracture behaviour of kaolin refractories
Abstract
Both the okra and "mrenda" binders were separately prepared from vegetables by boiling
in water and sieving to get the filtrate. The chemical compositions of the binders were
analyzed to determine both the organic and inorganic components. The test samples for
the modulus of rupture measurement were prepared using varying volume concentrations
of the okra binder from 0 (plain water) to 1.0 (undiluted binder). Notched samples for the
fracture toughness tests were prepared usi ng the optimum volume concentrations for
plasticization for both the okra and "mrenda" binders, while the control samples were
prepared using plain water. Cylindrical samples were prepared using the okra, "mrenda"
and plain water for the fatigue analysis. The bulk density and apparent porosity of the
samples were measured. The MOR for green and fired samples was measured using the
three-point bending technique. The pre and post thermal shock elastic modulus of the
samples was obtained using the ultrasonic non-destructive technique. The fracture
toughness of the notched samples was measured using the three-point bend test. For
fatigue analysis, samples plasticized with okra, "mrenda" and plain water were repeatedly
thermal-shocked from a given temperature to room temperature until failure. The Weibull
statistical approach was used to obtain the Weibull modulus and the slow crack growthparameter of the samples