Concrete is one of the most widely used construction materials. It is used in the construction of various kinds of buildings and structures, such as, commercial buildings, houses, bridges, and dams. Concrete consists of two main parts, which are, the binding materials and the mixing constituents. The binding materials compose of cement and water. The binding materials will bond the other mixing constituents, such as, sand, and aggregates or gravels, together. Chemical admixtures can also be added to enhance certain characteristics of concrete. Once mixed, concrete will remain in a plastic state for a certain period of time, which is long enough for it to be poured and cast into formworks of desired shapes. When concrete has fully solidified, it will gain more strength and will be able to carry high loads. When concrete components are initially mixed, the concrete will be in a plastic state. During this period, it is called”fresh concrete”. Once it is placed into formwork, it will begin to set and harden and will eventually be in a solid state. During the hardening phase up to being fully solidified, it is called “hardened concrete”.

Concrete generally consists of cement, water, aggregates, and admixtures, with the following approximate proportions.

+	Aggregates (sand + rocks) 70%
+	Cement 11%
+	Air content 2%
+	Water 17%

Fresh Concrete

Fresh concrete consists of solids, such as, aggregates and cement that are in suspension in liquid, which is water. The most important characteristic of fresh concrete is its workability, which refers to the behaviors of the fresh concrete when subjected to force.
The factors that have influence on the characteristics of fresh concrete are amount of water, properties of aggregates, type of cement, and admixtures. Apart from the mixing materials, other influential factors include the length of time, moisture level, and temperature.
Ready Mixed Concrete refers to concrete that has been mixed and produced at batching plants and ready to be transported to construction sites in the form of fresh concrete, which can be used readily.
In general, there are 3 methods of batching concrete.
	1.	Central Mixed Concrete. This mixing method refers to the concrete that is completely mixed at the batching plant in a stationary mixer. The fresh concrete that has been mixed completely will be sent or transported by either a truck agitator or a truck mixer.
	2.	Shrink-Mixed Concrete. This kind of concrete is partially mixed at the batching plant in a stationary mixer. The concrete will be completely mixed later in a truck mixer.
	3.	Truck-Mixed Concrete. On the contrary to the central mixed concrete, this kind of concrete is completely mixed in a truck mixer from start to finish.