In General Specification of Civil Engineering Works (1992 Edition), in Clause 10.09 it states “Fine aggregate for concrete shall be natural river-deposited sand consisting of at least 95% by mass of quartz grains”.
The aim of such specification is to control the quality of river sand.
As quartz is a durable and hard material, using a high percentage of quartz in aggregates of concrete can enhance the strength and durability of the
surface texture of concrete carriageway.
Advertisements
In addition, such specification requires a high percentage of quartz content, thereby reducing the probability of presence of impurities like shell.
This question is taken from book named – A Self Learning Manual – Mastering Different Fields of Civil Engineering Works (VC-Q-A-Method) by Vincent T. H. CHU.
If you have a query, you can ask a question here.