What is setting time and consistency of cement?
Table of Contents
- 1 What is setting time and consistency of cement?
- 2 What is concrete consistency?
- 3 What is the significance of setting time?
- 4 How do you find the initial setting time of cement?
- 5 What is the difference between setting of cement and hardening of cement?
- 6 What is the final setting time?
- 7 What is the final setting time of concrete at room temperature?
- 8 What is the setting of cement?
What is setting time and consistency of cement?
Standard Specification of Setting Time for Different Type of Cement
| Cement Type | Initial Setting Time, min (min.) | Final Setting Time, min (max.) |
|---|---|---|
| High alumina | 30 | 600 |
| Super sulphated | 30 | 600 |
| Low heat | 60 | 600 |
| Masonry cement | 90 | 1440 |
What is concrete consistency?
A. Consistency is the relative mobility or ability of freshly mixed concrete to flow. It includes the entire range of fluidity from the driest to the wettest possible mixtures. Plastic consistency indicates a condition where applied stress will result in continuous deformation without rupture.
What are the factors affecting the setting time of cement?
The major factors affecting the time of setting are cement composition, water-cementitious material ratio (w/cm), temperature, and admixtures. When cement hydrates faster, the time of setting is reduced. Increases in the w/cm result in increased time of setting.
How does the consistency of cement affects the properties in concrete?
Consistency plays a vital role in the determination of compressive strength of concrete or workability test for concrete. Less water than this quantity would not complete chemical reaction thus resulting in the reduction of strength and more water would increase water-cement ratio and so would reduce its strength.
What is the significance of setting time?
Initial setting time: is the time within which the cement can be molded in any desired shape without losing its strength. This is the time at which the hardening of the cement starts and the only time available for mixing the paste and placing it in position. If delayed further the cement loses its strength.
How do you find the initial setting time of cement?
Fig. The period elapsing between the time when water is added to the cement and the time at which the needle fails to pierce the test block to a point 5.0 ± 0.5 mm measured from the bottom of the mould shall be the initial setting time.
What is difference between setting and hardening of cement?
Setting describes the stiffening of the fresh cement paste. Onset of rigidity occurs. Then hardening begins, which indicates that a useful and measurable strength is developing. Setting and hardening result from the continuing reaction between the cementitious material and water.
What does concrete set time mean?
Concrete Time Of Set Typically to a concrete contractor, initial time of set refers to the time at which a concrete surface can bear the weight of an individual with minimal indentation. When water comes into contact with hydraulic cement, a chemical reaction called hydration occurs.
What is the difference between setting of cement and hardening of cement?
What is the final setting time?
The final setting time is the time elapsed between the moment the water is added to the cement, and the time when the paste has completely lost its plasticity and has attained sufficient firmness to resist certain definite pressure.
What is the standard consistency of cement?
By Standardising the consistency of cement, we know that how much of water is required to produce an effective cement which will eventually produce good quality of concrete. Standard Consistency of an ordinary Portland cement varies between 25-35\%.
How to measure the initial setting time of cement?
1. For determining the initial setting time of cement, place this mould filled with cement paste below the Vicat apparatus and fit the needle used for testing the initial setting time. 2. Lower the bottom of the needle such that it touches the top of cement paste filled in mould.
What is the final setting time of concrete at room temperature?
There is no relationship between setting time and rate of strength development of concrete. Final setting time is approximately equal to 90 + 1.2 times initial setting time for normal Portland cement at room temperature. 1) Vicat’s apparatus with mould and non-porous plate as per IS: 4031 (Part-V) 1988
What is the setting of cement?
To determine the initial and final setting time of a given cement sample The term setting of cement is used to describe the stiffening of cement paste. When cement is mixed with water, the three main components of cement i.e. tri-calcium silicate (C 3 S), tri-calcium aluminate (C 3 A), and dicalcium silicate (C s S) react with water.