Category: Laboratory Tests

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Laboratory Tests

Aggregate Impact Value Test

In construction of roads the aggregates should be in standard of R.D.A. To check that Aggregate impact value test is performed. If the AIV is greater than 30 that aggregate is not suitable for the work.

Procedure

  • Sample of aggregate passing 14mm sieve and retain on 10 mm sieve was taken.
  • Put into a metal tray and compacted by tamping rod for 3 layers.
  • Measure the weight.
  • Three samples were taken as same procedure.
  • Samples were sieved by 2.36 mm sieve.
  • Weights of retain and passing were measured.
  • Aggregate impact value = Wt. of road sample/Wt. of passed sample

Categories
Laboratory Tests

Field Density Test

 Test Procedure

  • First placed the field density plate on the place where the density should be measure.
  • Then dig a pit having a depth around 6’’ and a diameter of the inner circle of the field density plate.
  • Took the gravel from the dig and measured the weight.
  • Measure the weight of the FD bottle.
  • After that turn up down the bottle and kept the edge of the cone of the FD bottle on the plate and opened the tap at the neck and let the sand fill the pit.
  • Then, measure the weight of the bottle with the rest of the sand retained in the bottle.
  • Volume of sand filled the pit was calculated.
  • The sand of the bottle should be passed through 1.18 mm sieve and retained on     0.6 mm sieve.

Categories
Laboratory Tests

Standard Compaction Test

In road construction it is necessary to know optimum water content for a soil for compaction. By Standard compaction test it is measured.Test Procedure

  • Sample was split using sample splitter.
  • Sample was passed through 20 mm sieve and 2 kg of soil was taken.
  • Water until the soil gets stiffened.
  • Put wet sample into mould and gave 25 blows by 2.5 kg hammer from 380 mm height.
  • Procedure was done for 3 layers.
  • Weight of the soil was measured.
  • Another sample was taken from the same mixture and measured the weight of wet and dried (after oven  dry) for moisture content.
  • Pouring 75 ml water to the mixture, same procedure was done for 4 times.