Concrete testing is relevant to the construction industry as it checks if the concrete cast passed the structural requirements. This is a quality check and control to determine whether formworks and shoring can then be dismantled (for suspended section), and slab on grade or bridges may be opened to traffics for stressing.
Engineers or Consultants are seeking these tests before proceeding any further works on site. Like column, no further casting will be made unless the quality engineer to submit the copy of test report marked as “pass” to the Engineer.
These are the following most common concrete tests:
1. Cylinder or Cube Sample Compression Test
The test requires the use of compression testing machine, caliper, weighing scale and feeler gauges. Cylinders or cubes concrete samples taken from a fresh concrete supply are cured in a chamber. Samples are then compressed by applying loads increasingly and not abruptly until the maximum load is applied to failure. Record the result if the machine used does not record result automatically. This test also determines the likelihood of failure the specimen will experience.
2. Split Tension Test
Although concrete has considerably low tensile strength due to is brittle property, this test is important to determine the load which concrete may crack. A splitting testing machine is used for this test.
3. Beam Flexural Test
This test is conducted to determine the tensile strength of unreinforced concrete beam or slab to resist bending. This is relevant for pavement designing because designers base flexure theory for computations. This is also important for beams and girders on high-rise buildings and bridges. Generally, samples of length three times the depth are tested on a three-point loading test.
4. Rapid Chloride Ion Penetration Test
This test determines the durability and corrosion resistance of concrete. Reinforcing bars in the concrete may be deteriorated by rust due to moisture or chloride ingress. This is basically conducted for projects exposed to seawater or concrete below ground level. A sample is coated with epoxy that is allowed to dry and put in a vacuum chamber for 3 hours. The sample is then filled with Sodium solution and connected to an electric source. The readings have a corresponding interpretation that determines the penetration.
5. Slump Test
This is probably the cheapest concrete as you do this on site and you do not need any laboratory apparatuses and machines only thermometer.
6. Air Content Test
This test determines the air content in a concrete. This test is usually taken to countries with winter season to determine frost-related damages but it can also be taken in another country like UAE. Cylindrical samples are sealed in a cylindrical assembly attached to a graduated tube with water and gauge. The assembly will then be compressed allowing air to escape until a certain reading is attained. The drop of water volume on the graduated cylinder is the apparent air content of the concrete.
7. Water Permeability Test
This test determines the durability of concrete. These are mostly conducted for member or structures that are exposed to earth or water like foundations, water tanks, and retaining walls. Specimen samples are taken from fresh concrete and are allowed to cure on a curing tank at 28 days age. Specimens then are broken down perpendicularly to determine the depth of penetration of water.
These are the tests of concrete we used on our site. If you have used any other test on your site you can add it up by commenting below.