Effect of Gradation of Fine Aggregate on  Development of Hairline Cracks in Wall Plaster

Dr. U. K. Das; B. B. Bhardwaj; B. Choudhury; G. Sapkota

Volume : III, Issue : V, May - 2013

Effect of Gradation of Fine Aggregate on Development of Hairline Cracks in Wall Plaster

Dr. U. K. Das, B. B. Bhardwaj, B. Choudhury, G. Sapkota

Abstract :

Crazing or mapping are hairline cracks which develop in cement plaster surfaces exposed to long hours of sun. Shrinkage is the main factor for development of these cracks. The common causes attributed to shrinkage, and consequently hairline cracking, of plaster are rich cement content, higher water content, poor quality of fine aggregate, excessive quantity fines in aggregate, improper curing etc. In any plastering work the one variable which is highly location dependent is the quality of fine aggregate. A quantitative knowledge of the effect of quality of sand on development of hairline cracks will help the field engineers to adjust other variables like cement content etc. for better control of crazing. In this work a laboratory study on the effect of gradation of fine aggregate on crack development in plaster for different cement contents is carried out and the results and analyses are presented. The effect of inadequate curing is also studied in this work.