What is “concrete curing” and “setting of concrete”?
Curing of concrete
Curing means maintaining the overall moisture of freshly placed concrete to finish the hydration process and help it achieve proper hardening, attain durability, and increase strength. It is keeping the concrete surface moist to reduce shrinkage.
Curing needs to be started at an early stage. It needs to begin when the surface of your concrete is hard enough for you to walk over it without damaging the structure.
Until this is possible, you need to keep the surface of the concrete moist and maintain the temperature by spraying or splashing water without using any force. The concrete is going to derive its strength from the hydration of cement.
If you neglect the curing of concrete during the early stages of hydration, your concrete’s overall quality will degrade. If it is not done correctly after placing the concrete, it will not develop the desired strength and bond characteristics.
Purpose of curing
Given below are the main reasons why you need to cure your concrete structure properly
- The resistance of your concrete to abrasion is raised drastically
- Curing your concrete will help you better protect the surface from sun and wind in the future
- The presence of water is critical for the chemical action which accompanies the settling of concrete
- If your curing is efficient, it should moderately increase the strength of your structure with age
- The impermeability and durability of your concrete will get increased while decreasing shrinkage
Importance of curing
Curing your concrete will help you protect the surface of your structure from the wind and sun. It helps in imparting better strength to the design. The durability of concrete plays a massive role in a building which can be significantly increased by proper curing.
For basic types of cement, the curing period can be anywhere from seven to fourteen days. If the curing is not done correctly, it can reduce your structure’s flexural and compressive strengths.
Even the weathering and frost resistances will get decreased if you do not cure your concrete correctly. You notice cracks being developed due to drying shrinkage, plastic shrinkage, and thermal effects if you do not cure your structure correctly.
Your concrete needs to be cured for about 28 days to develop the required strength. However, as the total rate of hydration and therefore the rate of development of strength reduces with time, it is not a good idea to cure your structure for the entire period of 28 days.
The minimum curing time for concrete depends on the type of concrete you are using for your project. High-early-strength cement tends to cure the fastest. Concrete that has curing periods ranging from 13 days to 30 days are specified for highway pavements.
Since there are too many variables involved, there cannot be a definite mandate on this matter. These variables include the ambient temperature, type of cement used, method of curing used, nature of the product, and more.
Ideally, increased curing periods are more desirable for better-quality concrete structures and results such as concrete floors, airfield pavements, and roads.
Setting of concrete
Changing mixed concrete from one state (fluid) to another (solid) is known as the setting of concrete. The setting time of cement and concrete is the same. When we mix water with concrete to make a paste, the reactions begin.
The finely crushed cement in its pure form is highly sensitive to water. The main compounds of concrete react quickly with water to make a jelly-like compound which begins to solidify and settle.
Setting time of concrete
The initial setting time is between when you add water to the concrete and when a needle fails to pierce 5 mm inside your test block of cement from underneath the mold. Thirty minutes is the minimum time required for the first phase of the curing to complete (60 minutes of low heat cement). The final setting time for concrete is a maximum of 600 minutes for most types of concrete.
Factors that may affect the setting time for concrete
Numerous factors may affect the total setting time of concrete after it has been mixed with water; these include:
- The total amount of gypsum in your concrete
- The composition of concrete
- The curing
- Concrete to cement ratio
- Types of admixtures used and more.
Controlling the setting
Most professionals add chemicals to the concrete mix to change the setting time of the structure. For instance, on a hot sunny day, your concrete structure may “set up” too fast to be leveled adequately and troweled to give you the desired results.
However, during the cold months, we add chemicals that help speed up the entire setting process. Ready-mix experts from T&T Redi Mix add these chemicals during the initial mixing process depending on what you wish to achieve.
Want some more information about concrete? Talk to the professionals at T&T Redi Mix today!
Whether you wish to add a patio to your backyard or your community needs a new road, we have got what it takes to get the job done perfectly.
Conveniently located in Gunter, Texas, we deliver fantastic quality concrete to all major surrounding cities and everywhere else in between. Give us a call at (214) 785-8037, and we will answer all your queries.