How Does Mica Contents in Sand Affects Characteristics of Concrete

摘要

The sand deposited along the bed of rivers generally contains mica particles in fair proportions. While there is general awareness with regard to the deleterious effect of using micaceous sand on the properties of concrete, the experimental evidence bearing on that aspect is lacking. The extent, to which mica contained in sand could be deleterious, when used in concrete mixes came up for consideration recently in connection with NJPC, Nathpa Jhakri Project in Himachal Pradesh (H.P.) in India. While the source of sand available is in close proximity of construction site and obviously, most economical to use in concrete construction, has a content of mica particles to an extent of percent. The alternative source of sand with negligible mica content is on the other hand far away from the site of work. In this paper experimental investigations were carried out with sand containing mica content ranging from 2 percent to 12 percent and studied its effect on compressive strength, split strength, workability and unit weight of concrete. The sand deposited along the bed of the various rivers in our country, particularly its alluvial plains is known to contain a fair to significant proportion of mica particles.