Sampling

Ready made concrete must be tested on site directly as regards its workability and indirectly as regards to its strength.

Workability is tested by conducting the slump test while the possible strength concrete can reach in perfect conditions is tested by conducting the compression test. The strength is measured in megapascals 28 days after the mixing.

 

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The first step for conducting the tests is to take a test sample from a large batch of concrete. The sample must be representative of the concrete supplied.

  • The sample must be taken in a stroller

  • The time elapsed between taking the sample and preparing the cube must not exceed 15 minutes.

  • The mold must be lightly oiled with mineral oil before used.

  • Each mold is filled with a small scoop

  • For the condensation of the sample a square steel bar 25x25mm with rounded edges, is used. The mold is filled every three layers and is compacted with 36 beats in each layer.

  • The condensation is done immediately after the placement of concrete on the mold without interruption. After finishing the procedure the sample is numbered

  • Each sample should display the number of the waybill as well as the time of sampling.

  • The cubes remain in the factory in the molds highly protected from anything that can cause them damage. They must not be exposed in the sun and be protected from air for no more than 32 hours

  • After removing the molds, the cubes are maintained at 18-22c temperature of at least 90% humidity.

  • The samples can be kept in the temperature controlled room of the GGS laboratory if the costumer wishes.

  • Cubes that were not properly maintained will not be tested

  • The company assumes no responsibility for the bad quality of mixed designs whose production was indicated by the costumer.

  • The company assumes no responsibility for the results of tests that have not followed the above mentioned procedures.

 

Ordering Concrete

 

When ordering concrete you will need to tell the supplier:

  • Name and address for delivery

  • The use of concrete

  • The class of the concrete

  • The slump of the concrete

  • The amount you need in cubic meters

  • Any admixtures you may want in the concrete

  • How you want to place the concrete (e.g. pump)