CONCRETE TEST

CONCRETE TEST

There are following tests of concrete

• Compaction Factor Test
• Slump Cone Test

Compaction Factor Test

        Compaction of concrete is the process of removal of the air bubbles which are entrapped in the concrete, to give maximum density to the concrete. This test is developed to estimate the workability of the concrete.

       There are three vessels in this instrument. One is the cylindrical vessel, while others are hopper type. These are arranged one above the other like that, hopper B is placed below A, cylindrical vessel C is placed below the hopper B . The vessel A is filled with the sample of concrete. The hinged door which is provided at the bottom of vessel A is opened out so that, the concrete falls in to the cylinder. The concrete of cylinder are now weighed let it to be W1

  Now after removing the concrete the cylinder is again filled with the sample in 5cm layers which is compacted by ramming and vibrating and then weighed let it to be W2 

   The compaction factor= w1 /w2

 The following conclusions are made based on the value of the compacting factor

Value of compacting factor	Standard of workablility
0.95	Good
0.92	Medium
0.85	Low

Slump Cone Test

         This test is used to fine out the consistency of concrete. Consistency of concrete means the fluidity of concrete. 

         Concrete is filled in the standard slump cone which consists of a vessel whose shape is like a frustum of a cone, in four layers. Each ;ayer is tamped by means of hammer 20 times

 Immediately after filling, the cone is lifted slowly and the unsupported concrete will slump. The decrease in the height of the highest part of the slumped concrete is called slump,