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Outlining Various Tests on Concrete
Outlining Various Tests on Concrete: Concrete quality tests are conducted as part of the quality management process for concrete buildings.
Numerous concrete consistency checks, like compressive strength and slump tests, are applied to ensure the quality of the concrete supplied to meet a specified specification.
These tests provide information about the material’s properties such as resistance to load and air content.
Tests on Concrete
Each test performed on concrete gives information on a certain aspect of concrete. We will not be able to test all the properties of concrete. We must select the most appropriate tests that can include an accurate assessment of the concrete’s consistency, depending on the specific situation.
The primary consistency test identifies deviations from the appropriate and normal concrete specifications. The consistency checks ensure that the highest-quality concrete is placed on-site, resulting in concrete structural members of the required strength. The following are the results of consistency checks performed on fresh and hardened concrete.
Tests Performed on Fresh Concrete
The most often performed quality tests on fresh concrete are as follows:
1. Workability
The Vee-bee consistometer test, the slump test and the compaction factor test are used to determine the workability of concrete mixtures.
2. Content of Air
Air content indicates the total volume of air in a sample of fresh concrete but not the final in-place air value, since any air is lost during transportation, casting and finishing processes.
3. Time of Setting
The process of converting mixed cement from a liquid to a solid state is referred to as “Setting of Cement.”
The Initial Setting Time is specified as the time interval between the addition of water to the cement and the failure of a needle with a 1 mm square segment to pierce the test block to a depth of approximately 5 mm from the mold bottom.
The Final Setting Time is known as the time interval between the addition of water to the cement and the impression made on the test block by a needle with a 1 mm square segment and a 5 mm diameter connection.
Tests Performed on Hardened Concrete
The most often performed quality tests on reinforced concrete are as follows:
1. Compressive strength
The compressive strength of concrete gives information on all of the concrete’s properties.
2. Tensile strength properties
Tensile strength is a fundamental and critical property of concrete that has a significant effect on the degree and scale of cracking in structures. Additionally, owing to the concrete’s porous composition, it is very unstable under stress. As a result, it is not supposed to withstand direct stress. Thus, as tensile forces exceed the tensile strength of concrete, cracks form. As a result, it is important to calculate the tensile strength of concrete in order to determine the maximum strain that the concrete members will withstand without cracking.
3. Elastic modulus
The modulus of elasticity of concrete is defined as the ratio of stress to strain in the concrete when loads are applied.
4. Concrete Permeability Tests
When concrete is permeable, it can result in degradation of the reinforcement when exposed to oxygen, moisture, CO2, SO3-, and Cl-, among other things. Corrosion results in the accumulation of rust that is almost six times the volume of the steel oxide sheet, causing cracking of reinforced concrete and spalling of the concrete to begin.
5. On-site evaluation of concrete
Numerous in-situ tests, both destructive and non-destructive, are performed on reinforced concrete. A few of these are the concrete pull-out test and the Schmidt Hammer test.
Compressive Strength and Slump
Among the tests mentioned above, the two major tests mainly considered as quality tests are the compression tests and slump tests. The causes are:
- The majority of the properties of concrete are equivalent to the compressive strength determined by a compressive strength test.
- Compressive strength testing is the simplest, most inexpensive, and most precise test available.
- Compressive strength measurements are the most effective method for determining the variability of concrete.
- The slump test is used to determine the mix’s quality. This research examines the variety of building materials used within the blend. These measurements are designed to determine the concrete mix’s water-cement ratio.
- The slump test is simple to administer. It rapidly decides the consistency of concrete prior to its placement. The criteria for placement are those recommended by the applicable concrete practice codes.
- Slump testing is performed on-site and does not require a laboratory or costly testing equipment. As a result, this test is cost effective.
- Before pouring into the formwork, we run a slump inspection. As a result, if there is a problem with the consistency of the concrete, the checked batch will be discarded. Which will assist in raising a deficient structural member and preventing potential disassembly and repair.
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