Introduction To Cement Setting Time
The factors affecting the setting time of cement, is one of those building terms you must know; even if you are not a constructor. Yes, you must be abreast of this before they begin constructing your new house, store, church, hotel, etc for you.
In here, I mean in this article, you are going to know “what the setting time of cement means and more importantly, you will discover the factors that affect the setting time of cement”. Do you know the various types of cement and their uses? If not, keep reading further!
Take note, this post is basically designed for educational purposes and nothing else.
What Is The Setting Time Of Cement?
The setting time of cement, can be put into two divisions: Initial setting time and Final setting time.
Before we get deeper into the two divisions, it should be noted that: cement + water = paste, paste + fine aggregate = mortar, mortar + coarse aggregate = concrete. When water is mixed with cement, the immediate product is paste which becomes less plastic with time. As time goes on, the paste becomes a hard mass.
Check Also: The Types Of Cement And Their Uses
Initial Setting Time Of Cement
Initial setting time is the period of time required to delay the process of hydration (or hardening). Simply put, the initial setting time of a concrete is the time in which a cement paste begins to harden.
Final Setting Time Of Cement
Also, the Final setting time is the period of time in which the paste completely loses its plasticity.
We can also say that, the Final setting time, is the time in which a cement paste has hardened sufficiently and attain the shape of the mould in which it is discharged.
Check Also: The Types Of Cement And Their Uses
Factors Affecting The Setting Time Of Cement
As cement hydrates rapidly, the time of setting is reduced. Without any ado, check the factors that affect the setting time of cement.
Cement’s Composition
The setting and hardening of cement, is mainly influenced by the mineral compositions and their distributions (or ratios) in the cement.
These mineral components posses distinct characteristics that influence the setting time of the cement upon reacting with water. For instance, C3A can speed up the setting and hardening rate of cement
Check Also: The Types Of Cement And Their Uses
Amount Of Gypsum
Gypsum is mostly used for regulating the setting time of cement and it is a very vital component. Overmuch gypsum will speed up the setting of cement and this will lower the strength of the cement. Therefore, the quantity of gypsum should fall around 3%-5% of the cement’s mass.
Quantity Of Mixing Water Content
Basically, increasing the mixing water content will render the cement paste to be weak and this will eventually extend the setting time of the cement.
Other notable factors that affect the setting time of cement are: admixtures, curing conditions, storage conditions, curing age and cement’s fineness.
