M20 Grade of Concrete: In this article, you will know the Two methods for making M20 Grade of Concrete at the Construction Site. In the first method, we use the Measuring Box, and in the second method, we use Mortar Pan. Generally, these two methods are adopted nowadays.
The standard Dimension of Measuring Box = 1 feet x 1 Feet x 1 Feet 3 inch (1′ x 1′ x 1.25′)
Volume of Measuring Box = 1.25 CFT = 0.03539 cum.
Now let’s find the Volume of 1 Bag of Cement.
Density of Cement = 1440 Kg/m3
Weight of 1 Bag of Cement = 50 kg
Volume of 1 Bag of Cement = Weight of 1 Bag of cement /Density of Cement
= 50/1440 = 0.03472 m3
As we know 1 m3 = 1000 Liters.
Therefore, Volume of 1 Bag of Cement = 0.03472 x 1000 = 34.72 Liter. From easy calculation, we consider the volume of 1 Bag of cement = 35 liter.
Volume of 1 Bag of Cement = Volume of measuring Box.
Let’s make the Nominal Mix of M20 Grade of Concrete.
As per IS 456-2000, The ratio of Proportion of Grade of Concrete is 1:1.5:3. Where 1 is the part of Cement, 1.5 is the part of Fine Aggregate (sand) and 3 is the part of Aggregate.
Proportion of M 15 Grade of Concrete in terms of Liters
Cement = 1 x 35 liters = 35 Liters.
Sand = 1.5 x 35 Liters = 52.5 Liters.
Aggregate = 3 x 35 Liters = 105 liters.
Proportion of M 20 Grade of Concrete in terms of Measuring Box
Cement = 1 Measuring Box = 1 Bag of Cement.
Fine Aggregate (Sand) = 1.5 Measuring Box or 1.5 Farma.
Coarse Aggregate = 3 Measuring Box or 3 Farma.
Consider the Water Cement Ration for this Grade of Concrete is 0.52.
Amount of Water shall require = Water Cement Ratio x Weight of 1 Bag of Cement.
Amount of Water shall Require = 0.52 x 50 = 26 Liters for One Batch of concrete.
In One batch to prepare M 20 grade of Concrete, 1 Bag of Cement: 1.5 Measuring Box of Sand: 3 Measuring Box of Coarse Aggregate is required.
Preparation of M 20 Grade of Concrete using Mortar Pan
In this method, we measure the Sand and Aggregate using Mortar Pan. This number of mortar pan depends upon its area. In the local language, Mortar Pan is also called Gamala, Tagar, etc.
The first step is to check how many number mortar pans are required to fill one bag of cement. According to my experience 4 Mortar are needed to fill up with one Bag of Cement.
1 Bag of Cement = 4 Mortar Pan.
Grade of Concrete to be Prepared = M 20 (1:1.5:3), Where 1=cement, 1.5 = Fine Aggregate (sand), 3 = Coarse Aggregate. so the proportion can be as follows.
Cement = One Bag = 4 Mortar Pan.
Sand = 1.5 x 4 Mortar Pan of Sand = 6 Mortar pan of Sand.
Coarse Aggregate = 3 x 4 Mortar pan of Coarse Aggregate = 12 Mortar Pan of Aggregate.
In One batch to prepare M 20 grade of Concrete, 1 Bag of Cement: 6 Mortar Pan of Sand: 12 Mortar Pan of Coarse Aggregate is required.