Is the result of shear slump acceptable?
Table of Contents
- 1 Is the result of shear slump acceptable?
- 2 What is a slump test which slump is acceptable for construction?
- 3 What does true slump indicate?
- 4 What is the value of true slump?
- 5 How is shear slump measured?
- 6 What should be the value of true slump?
- 7 What does a shear slump in concrete mean?
- 8 What are the different types of slumps in construction?
Is the result of shear slump acceptable?
The slump test must be repeated in order to avoid shear slump. Shear slump indicates that the concrete is not compacted. It may undergo bleeding and segregation so shear slump is undesirable for the durability of the concrete. If we get a shear slump, concrete is not acceptable due to lack of cohesion.
What is a slump test which slump is acceptable for construction?
The slump test is suitable for slumps of medium to low workability, slump in the range of 5 – 260 mm, the test fails to determine the difference in workability in stiff mixes which have zero slump, or for wet mixes that give a collapse slump. It is limited to concrete formed of aggregates of less than 38 mm (1.5 inch).
Why does Shear slump happen?
Shear slump: If one-half of the cone slides down in an inclined plane, it is called a shear slump. Shear slump indicates lack of cohesion in the concrete mix. Shear slump may occur in the case of a harsh mix. Collapse slump: In this case, fresh concrete collapses completely.
How do you get a true slump?
Starts here3:50TEST FOR WORKABILITY OF CONCRETE – SLUMP CONEYouTubeStart of suggested clipEnd of suggested clip61 second suggested clipThe mold is then removed by raising it gradually. The concrete will subside. This subsidence isMoreThe mold is then removed by raising it gradually. The concrete will subside. This subsidence is known as slump. This operation shall be carried out without any jerks or vibrations.
What does true slump indicate?
True slump refers to general drop of the concrete mass evenly all around without disintegration. It may undergo segregation and bleeding and thus is undesirable for the durability of concrete. Collapse slump indicates that concrete mix is too wet and the mix is regarded as harsh and lean.
What is the value of true slump?
What is the ideal value of slump? Answer 1 In case of a dry sample, slump will be in the range of 25-50 mm that is 1-2 inches. But in case of a wet concrete, the slump may vary from 150-175 mm or say 6-7 inches.
What is true slump?
What is the true slump value?
If the concrete slumps evenly it is called true slump. If one half of the cone slides down, it is called shear slump. In case of a shear slump, the slump value is measured as the difference in height between the height of the mould and the average value of the subsidence.
How is shear slump measured?
If one half of the cone slides down, it is called shear slump. In case of a shear slump, the slump value is measured as the difference in height between the height of the mould and the average value of the subsidence.
What should be the value of true slump?
How do you interpret slump results?
In technical terms, slump is a measured indication of the workability, or flow, of a mix. The drier the mix, the lower or “tighter” the slump. Conversely, the wetter or “looser” the mix, the higher the slump.
What are the slump values recommended for different types of work?
Recommended Values of Concrete Slump Tests for Various Purposes:
| No. | Types of concrete Ad | Slump |
|---|---|---|
| 1 Ad | Concrete for road construction | 20 to 40 mm |
| 2 | Concrete for tops of curbs, parapets, piers, slabs and wall Ad | 40 to 50 mm |
| 3 Ad | Concrete for | 70 to 80 mm |
| 4 | Normal RCC work Ad | 80 to 150 mm |
What does a shear slump in concrete mean?
The shear slump indicates that the result is incomplete, and concrete needs to be retested for valid results. If a shear or collapse slump is achieved, a fresh sample should be taken and the test is repeated. If the shear slump persists, as may the case with harsh mixes, this is an indication of lack of cohesion of the mix.
What are the different types of slumps in construction?
There are three types of slump that may occur in a slumps test, namely, true slump, shear slump and collapse slump. True slump refers to general drop of the concretemass evenly all around without disintegration. This type of slump is most desirable.
What is the procedure of concrete slump test?
Procedure of Concrete Slump test: The mold for the concrete slump test is a frustum of a cone, 300 mm (12 in) of height. The base is 200 mm (8in) in diameter and it has a smaller opening at the top of 100 mm (4 in). The base is placed on a smooth surface and the container is filled with concrete in three layers, whose workability is to be tested.
What are the ASTM standards for slump testing?
The ASTM standards also state in the procedure that when the cone is removed, it should be lifted up vertically, without any rotational movement at all. The concrete slump test is known as “Standard Test Method for Slump of Hydraulic-Cement Concrete” and carries the code (ASTM C 143) or (AASHTO T 119).