all about Water Cement Ratio

What Is Water Cement Ratio | Water-Cement Ratio and Concrete Strength | Role of Water in Concrete

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all about Water Cement Ratio

What Is Water Cement Ratio?

What Is Water Cement Ratio?

It is the ratio of cement and water utilized in the preparation of concrete. The quantity of water used at mixing concrete is very important.

If the percentage of water used is less, then there will not be a sufficient quantity of water to hydrate cement. It will result in weak and porous concrete.

Therefore, the usual tendency is to use too much water which gives a more workable mix, but it doesn’t give sound concrete. Too much water results in the segregation of aggregates and give porous concrete of low strength and low density.

A certain minimum proportion of water is necessary to hydrate the cement completely. To create the concrete sufficiently workable to be placed in position, some more water is needed.

So long as the concrete is sufficiently workable, for the way of placing used, its strength depends on the proportion of water to the cement in the mix.

The water-cement ratio shouldn’t be allowed to exceed the specified limits for various types of concrete and should usually be kept as low as the methods of placing will allow.

Abrahms, as a result of a large number of experiments, states that“with given materials and conditions of the test, the ratio of the quantity of mixing water into the quantity of cement alone determines the potency of concrete as long as the mix is of workable plasticity.“

This is known as water-cement ratio law. According to this law, the strength of concrete won’t increase by simply increasing the quantity of cement unless the water-cement ratio is reduced.

Required Water-Cement Ratio (British Standard Specifications)

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Proportion
Water-Cement Ratio
1:02:04 0.58
1:1.5:3 0.51
1:01:02 0.43

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Water-Cement Ratio Table

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Exposure Plain Cement Ratio Reinforced Cement Concrete
IS 10262 Minimum Cement Content W/C Ratio Grade Minimum Cement Content W/C Ratio Grade
Mild 220 0.6 300 0.55 M20
Moderate 240 0.6 M15 300 0.5 M25
Severe 250 0.5 M20 320 0.45 M30
Very Severe 260 0.45 M20 340 0.45 M35
Extreme 280 0.4 M25 360 0.4 M40

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Different Water Cement Ratios

Different Water Cement Ratios

Different Water-cement ratios are utilized for different concrete applications. For high-quality concrete construction, a lower water-cement ratio of 0.4 could be employed.

For concrete construction like sidewalks and drives, a w/c ratio ranging from 0.6 to 0.7 is normally used.

The practical range of water-cement ratio ranges from 0.3 to 0.8, which gives weak and stiff concrete, respectively. Weak concrete means a fairly wet concrete.

Compressive strength of about 5600 psi can be obtained in the concrete of the water-cement ratio 0.4. This value will go down to 2000 psi when a water-cement ratio of 0.8 is used.

Also Read: Concrete Material Calculation / Concrete Quantity

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Water-Cement Ratio and Concrete Strength

Water-Cement Ratio and Concrete Strength

The general concrete strength is reduced with the increase in the water-cement ratio. The addition of more water gives dilute paste, which has more pores at the micro-level.

These make the concrete weak and results in shrinkage and cracks and issues. The Cement and aggregates particles take the excess water that’s present in concrete.

This consumption is uncontrollable if a large excess of water is present in the concrete. Therefore, separate water channels are created, resulting in bleeding on the surface.

This creates weak zones in concrete that are susceptible to cracking under service loads.

A lower water-cement ratio may contribute to high strength and high-quality concrete. But the water-cement ratio alone cannot give good concrete.

A good mix proportion and quality aggregates and binding materials contribute to a good mix design. A low water-cement ratio is thus one of the factors influencing good mix design.

Also Read: 10 Different Types of Loads on Structures | What Are Structural Loads

Water-Cement Ratio and Permeability

Water-Cement Ratio and Permeability

A mix design using a lower water-cement ratio or higher cement content will give low permeability concrete. A high strength concrete tends to give less pervious concrete.

This will increase the durability of the concrete structure. The above figure shows the relationship between the concrete water-cement ratio and the coefficient of permeability.

Role of Water in Concrete

Role of Water in Concrete

It contains micro-ingredients like cement, sand, fine aggregate & Coarse aggregate. To acquire high-strength concrete, that withstands up to our desired compressive strength, We need a correct proportion of admixture to combine those materials.

Here comes the Water, which will initiate this chemical process by incorporating 23% to 25% of the cement volume.

This initiates the chemical process and makes 15% of water-cement paste, also known as a gel, to fill the voids in the concrete.

Also Read: What Is Waterproofing | Types of Waterproofing

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How to Calculate Water Cement Ratio? – W/C Ratio Calculation

How to Calculate Water Cement Ratio?

We do not calculate the W/C Ratio. It is selected from various workability tests based on the structural members, transportation, concrete strength, selection of aggregation, etc.

At Site Level, we can make use of the below calculation for the nominal mix.

It is a guide to make your judgment.

Water Cement Ratio as per IS 10262-2009 Table-5

As you can see from the Chart, the W/C Ratio varies from 0.4 to 0.7 depending on exposure conditions. If we need to calculate Water quantity for concrete, first find the cement content for the volume. If we Assume the required cement volume as 50kg, Required amount of water = W/C Ratio X Cement Volume Therefore, Required amount of water = 0.5 X 50 kg = 25 litres / 50 kg cement bag. For Design mix, the W/C Ratio will depend upon the workability, strength requirements. In IS 10262-2009 ANNEX A. they have explained the process for design mix. Hope that helps you. Water Cement Ratio Test We hope now you have a fair amount of knowledge on Water Cement ratio. It is time to test this vital task. How to test water cement ratio? We actually use Concrete Slump Test at the site level to check this workability & Consistency

Calculation of Water Cement Quantity for Concrete

Calculation of Water Cement Quantity for Concrete

  1. As you can see from the Chart, the W/C ratio varies from 0.4 to 0.7 depending on exposure conditions.
  2. If we need to calculate Water quantity for concrete, first find the cement content for the volume.
  3. If we Assume the required cement volume as 50kg,
  4. The required amount of water = W/C Ratio x Cement Volume
  5. Therefore, Required amount of water = 0.45 x 50 kg = 22.50 litres / 50 kg cement bag.
  6. For the Design mix, the W/C ratio will depend upon the workability, strength requirements.
  7. In IS 10262-2009 Annex-A, they have explained the process for the design mix.

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Water Cement Ratio

The water-cement ratio in concrete is the ratio of the weight of water to the weight of cement used in a mix. It greatly influences the strength and durability of concrete, with lower ratios generally leading to stronger and more durable concrete.

Water Cement Ratio and Concrete Strength

A w/c ratio of 0.4 means that for every 100 lbs of cement used in the concrete, 40 lbs of water is added. These two ingredients, cement and water, are responsible for binding everything together. The w/c ratio largely determines the strength and durability of the concrete when it is cured properly.

Role of Water in Concrete

As water is added to cement it creates a paste that glues all of the aggregates together. The cement paste then undergoes a chemical process known as hydration, this chemical reaction is what allows the concrete to harden and become strong and solid.

How to Calculate Water Cement Ratio?

The water to cement ratio is calculated by dividing the water in one cubic yard of the mix ( in pounds) by the cement in the mix (in pounds).

How Do You Calculate Water Cement Ratio?

The water to cement ratio is calculated by dividing the water in one cubic yard of the mix ( in pounds) by the cement in the mix (in pounds). So if one cubic yard of the mix has 235 pounds of water and 470 pounds of cement- the mix is a . 50 water to cement ratio.

Formula to Water Ratio

Powdered formulas are mixed 2 ounces (60 mL) of water per each level scoop of powder. Never add extra water because dilute formula can cause a seizure. Powdered formula costs the least. Ready-to-feed formula costs the most.

Concrete to Water Ratio

Typical Water-Cement Ratios in Concrete Mixes
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 weak concrete.

Water to Weight Ratio

Most people need to drink roughly half of their weight (in pounds) in ounces. For example, a 200-pound adult needs approximately 100 ounces of water each day.

Water Cement Ratio for High Strength Concrete

0.40 to 0.60
Water–cement ratios in the range of 0.40 to 0.60 are typically used. For higher-strength concrete, lower w/c ratios are necessary, along with a plasticizer to increase flowability.

Quikrete Water Ratio

QUIKRETE Concrete Mix may also be mixed by hand. Empty concrete bags into a suitable mixing container. For each 80 lb (36.2 kg) bag of mix, add approximately 6 pt (2.8 L) of clean water. Work the mix with a shovel, rake or hoe and add water as needed until a stiff, moldable consistency is achieved.

High Strength Concrete Mix Ratio

High-Strength Concrete Mix
Cement-to-aggregate ratios in high-strength concrete mixtures are generally 1:2:2 or 1:1.5:2.5. This mixture is utilised in situations where significant strength is necessary, such as in heavy-duty or tall constructions.

Water Cement Ratio Formula

The water–cement ratio (w/c ratio, or water-to-cement ratio, sometimes also called the Water-Cement Factor, f) is the ratio of the mass of water (w) to the mass of cement (c) used in a concrete mix: The typical values of this ratio f = w⁄c are generally comprised in the interval 0.40 and 0.60.

Water Cement Ratio in Concrete

It is the ratio of the mass of water to the mass of cement added to concrete. The water cement ratio formula directly affects the strength & durability of the concrete. The typical water-cement ratio varies between 0.40 – 0.60 for different grades of concrete mix.

How to Calculate Compressive Strength of Concrete?

The formula is: CS = F ÷ A, where CS is the compressive strength, F is the force or load at point of failure and A is the initial cross-sectional surface area.

How to Calculate Water to Cement Ratio?

For example if the water-cement ratio is 0.50 for concrete and cement added is 50 kg (weight of 1 bag of cement). Water = 0.50 x 50 = 25 liters. As you see, the water is reduced as we decrease the water-cement ratio.

Quikrete Fast Setting Water Ratio

Pour water into the dry mix until the powder is saturated with water. Depending on soil conditions, this will require about 1 gallon (3.8 L) of water per 50 lb (22.7 kg) bag. For holes deeper than 2′ 6″ (0.8 m), place the material in lifts of 2′ 6″ (0.8 m) or less to allow water to soak all the way through.

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