Calculate the Water Cement Ratio Know all importance of the ratio. Low Water cement ratio impacts all of the desired properties of concrete. The water to cement ratio is calculated by dividing the water in one cubic yard of the mix by the cement in the mix. Concrete as a porous material has air/water permeable properties and this has a great influence on not only strength but also durability characteristics.
What is Water cement ratio:
Water Cement Ratio means the ratio between the weight of water to the weight of cement used in the concrete mix. The quantity of water in concrete added to the cement while preparing concrete mixes has been known as much impact of the quality of concrete.
What happen when, lower water-cement ratios produce stronger, more durable PCC. The water consumptions of the other two ratios are the same with one of the standard ratios. In concrete mix design, W/C ratio stated, the ratio of the amount of water to the amount of cement used is called the water to cement ratio (w/c). These two ingredients are responsible for binding everything together, going together strong.
High Water Cement Ratio: On this issue, in construction matters concrete with higher W/C Ratio is also showing impact on cracking and shrinkage. Using water concrete ratio is the usual way to achieve high strength and high-quality concrete. Using half .50 water to cement ratio when concrete is exposed to freezing and thawing in a moist condition. Use a maximum .45 water to cement ratio for concrete with severe or very severe sulfate conditions If we keep on adding water to increase the workability then the concrete has lots of fluid materials where the aggregates will settle down. Once the water evaporated it leaves lots of voids in concrete which affects the concrete strength. Water Cement mix proportion and quality aggregates and binding materials contribute to good mix design. A low water-cement ratio is hence one of the factors influencing good mix design. Waer is a hydrates the cement, which is an essential chemical reaction for formation of complex silicate crystalline gels that are responsible for the strength of the cement.
It lubricates all the concrete ingredients, by passing around them in the form of films. The workability of concrete depends upon the quantity of water used in it. All materials used for design including the water quality should be to a high standard. A general rule of thumb is, if the water is palatable then it is suitable for mixing concrete. if there is a low water to cement ratio in a fresh mix than after hardening, water/cement will not be able to lead higher strength of concrete. strength of concrete with water to cement ratio.
W/c is the water to cement ratio in the concrete mix.
K1 and k2 are the empirical constants.
It is very simple relation and it is like the same as presented by Rene Feret in 1896. Both have related volumes of water/cement with strength of concrete.
fc is the concrete strength.
w, a, and c are the absolute volumetric proportions of water, air and cement.
K is the empirical constant.
Water-Cement Ratios in Concrete
Typical w/c ratios are as follows:
Normal for ordinary concrete (sidewalks and driveways): 0.6 to 0.7
Specified if a higher quality concrete is desired: 0.4
The practical range of the w/c ratio is from about 0.3 to over 0.8.
A ratio of 0.3 is very stiff (unless superplasticizers are used).
A ratio of 0.8 makes a wet and fairly weak concrete.
Typical compressive strengths when concrete is properly cured are:
0.4 w/c ratio –> 5600 psi
0.8 w/c ratio –> 2000 psi.
Effect of W/C Ratio on Durability:
How much Quality of water is added in concrete M20 Grades. here you can check explained about how to find quantity of cement. concrete mixture of cement, sand, aggregate and water. Concrete mix design need different quality of water. Excessive use of water in concrete may leads to shrinkage and creeping.
The ratio of water to cement used in concrete affects its ultimate strength. If too little water is used the concrete is so stiff that it cannot be compacted and if too much water is used the concrete does not develop full strength. Very little water is required to ensure that a full chemical reaction takes place within the concrete mix. Any excess water will not be used and will leave very small voids within the concrete when the unused water eventually evaporates away. The water added must be sufficient to
The amount of water required to make concrete sufficiently plastic (workable) depends on the position in which the concrete is to be placed. Plasticizers are added to the concrete mixture and enable the concrete to be more workable and fluid without increasing the quantities of water used. Using plasticizers keeps the strength of the concrete high without increasing the quantity of cement.