27/04/2019
Another prominent material used in mortar and concrete mixtures during construction is sand. It is made up of finely divided rocks and mineral particles. Color of sand varies in different regions. It is available in Punjab and KPK region is greyish in tone where as it is available in Karachi, coastal areas of Sindh and Baluchistan has a light brownish tone. It is extracted from open pits either from riverbeds or from beaches. However there are several inland and non-coastal sand ridges across the country especially in Punjab and Baluchistan that are used for it’s mining.
It is named after the region or river from which it is extracted. In Punjab, available sands are:
1 Ravi
2 Chenab
3 Lawrencepur
4 Ghazi
QUANTITY CHECK ON SITE:
It is delivered on sites through dumpers or trolleys. Its quantity is calculated in unit of cubic feet, also referred to as “sankra” in local language. If it is delivered in trolleys then its calculation is a complicated process. Most of the trolleys either consist of 250 cubic feet (2.5 sankra) of sand or maximum of 400 cubic feet (4 sankra). In case of dumpers calculation is very easy and it must be done to stay safe from fraudulent dealers who tend to charge more on basis of fake quantities. Calculation is simple, take the inner measurements of dumpers storage area, measure length, width and depth with a help of steel road. Depth should be measured carefully only up to the extent at which sand is present. If measurements comes out in whole figures then:
Total Quantity = Length (ft.) x Width (ft.) x Depth (ft.)
In other case if the figures are not whole, then covert the architectural measurements into decimal measurements by following method:
Suppose,
Length = 15’8” (15 feet & 8 inches)
Width = 7’4” (7 feet & 4 inches)
Depth = 9’10” (9 feet & 10 inches)
Feet figures will remain the same, convert figures of inches:
8” = 8/12 = .67
4” = 4/12 = .33
10”=10/12=.83
Hence,
Length = 15.67
Width = 7.33
Depth = 9.83
Total Quantity = 15.67 x 7.33 x 9.83 = 1130 cubic ft
QUALITY CHECK ON SITE:
It is a very critical material since it is used in mortar mixtures and concretes. In above mentioned available sands, best is extracted from Ghazi and lawrencepur and both are widely available in northern Punjab and KPK region. Lawrencepur is also available in Lahore region but at higher rates because of freight expenses. Out of remaining two, Chenab is the best sand to be used and is easily available in Central Punjab region. However quality check should always be carried out even if best of available is being used.
WATER TEST:
Drop a small quantity of sand in bucket of water, sand particles will not float on top. Content floating on the top will be clay or mud
Mud/soil content
Sand should be uniform in colour. If it were greyish sand, any content such as mud/soil would be easily visible in form of mass substances.