Effect of WPSA particle size to the morphology and compressive strength properties of hydrated cement paste contain WPSA as SCM

Abstract

Addition of waste material as Supplementary Cementitious Material (SCM) in blended cement has been proved to have a positive effect to cement matrix. It also as an alternative method to reduce the environmental problem regarding the waste management and Ordinary Portland Cement (OPC) production. This paper presents the effect of particle size of Waste Paper Sludge Ash (WPSA) in the development of microstructure and compressive strength of hydrated blended cement paste. The replacement materials also included Fly Ash (FA) and Silica Fume (SF). Blended cement was prepared by replacing OPC at 5% mass to mass basis. Four sizes of WPSA was prepared which are unsieve, retained at 63μm, retained at 45μm and retained at pan. All prepared WPSA were used to produce four types of WPSA blended cement. The water to cement ratio (w/c) of 0.5 was used for all the blended cement paste mixes. The changes in microstructure of the hydrated sample were also studied using scanning electron microscope (SEM). Compressive strength of cement paste at 180 days was determined. The result showed that the filler effect of WPSA cement paste strength increased with smaller particle size. The mechanism of hydration of various blended cement is also discussed.