http://www.gharexpert.com/category/1399/Fine-Aggregate-0.aspx?CatID=1399Fine Aggregate information at GharExpert.com. Fine Aggregate having fineness modulus from 2.50 to 3.50 and silt contents not more than 4% shall be used for reinforced cement concrete work.http://www.gharexpert.com/articles/Fine-Aggregate-1501/Purchasing-Guidelines-Fine-Aggregate-Coarse-S_0.aspx?PL=2&ArticleID=1501&CatID=1399There should be no silt contents in Coarse Sand as the suppliers try to charge much amount by supplying the material of lowe quality.http://www.gharexpert.com/articles/Fine-Aggregate-1475/Specification-Fine-Aggregate-Coarse-Sand_0.aspx?PL=2&ArticleID=1475&CatID=1399Fine Aggregate may have more impact on the strength of the building than cement. This article explains the guidelines to check the quality of fine aggregate and purchasing guidelines