April 17, 2024

SPECIFIC GRAVITY AND WATER ABSORPTION OF AGGREGATE

Apparatus Required

  • Wire basket with 2.36mm aperture size,200mm diameter and 60mm height.
  • weigh balance 2kg capacity
  • suitable container for immersing the wire basket in water
  • suitable apparatus for suspending the wire basket from center of scale pan balance
  • Pycnometer 1 Liter capacity fitted with glass disk

Procedure of the test

Fine Aggregate (Pycnometer  method)

  • The sand sample shall be immersed in clean water for 24 hrs and dried to saturated surface dry condition.
  • A representative sample of about 1200 gms to be taken of the above sample is thus divided into two equal parts(600 gms each).
  • One sample is placed in an oven and dried to constant weight and the weight is recorded.
  • The pycnometer is filled about 3/4th full of water of a known temperature and the SSD sample is added, entrapped air is removed either by agitating the sand.
  • The jar is then filled with water and covered with a glass disk by sliding the disk across the top of the jar. the jar is shaken vigorously to remove the entrapped air if any and the disk again refilled with water,  make sure that no air voids present the weight of the jar with the disk is measured.
  • Weigh the pycnometer filled with water only.

Coarse Aggregate (Basket Method)

  • The sample immersed in water having a temperature of 22 to 32°C  and the mixture is thoroughly agitated to remove the dust and then allowed to absorb water for 24.
  • After weighing, the saturated surface dry sample is placed immediately in the wire basket and its weight in water is determined.
  • The sample is then dried to a constant weight at a temperature of 100 to 110° C, then cooled to room temperature and weighed .

Datasheet for specific gravity & water absorption of fine aggregate

Leave a Reply

Your email address will not be published. Required fields are marked *

error: Content is protected !!