Category: CONCRETE

# Find the cement bags, sand(CFT) & aggregate in M20, M15 concrete

## Calculate the Quantity of Cement, Sand & Aggregate in M20 Concrete

First of all, I want to assure you that it is very easy to determine the quantity of sand, cement, and aggregate in M20, M15, and M10 Concrete. So take a look carefully and will easily be understood.

Let’s take some examples,

Example: 1

Let’s assume that the volume of total concrete(wet concrete) required for a particular work is 2 m3. Now find out the quantity of cement, sand, and aggregate.

Solution:

In the case of M 20 concrete, the ratio of cement, sand, and aggregate is 1: 1.5: 3.

Dry volume of concrete = wet volume of concrete × 1.54 [ You can take this factor from 1.54 to 1.57 ]

Hence, the dry volume of concrete is = 2 × 1.54 = 3.08 m3

The required quantity of cement is = (Cement ratio ÷ Sum of all ratio) × Total volume of concrete = $\frac{1}{(1 + 1.5 + 3)} \times 3.08$ = 0.56 m3

### How do you calculate cement in bags?

First of all, we need to calculate it in kg. We know that the density of cement is 1440 kg/ m3. Therefore, 0.56 m3 cement means 0.56 × 1440 = 806.4 kg cement.

In general, each bag of cement weight is 50 kg.

So, the required number of cement bags are = 806.4 ÷ 50 = 16.12 ≈ 17 No.s.

Quantity of sand required = ( Sand ratio ÷ Sum of all ratio) × Total volume of concrete = $\frac{1.5}{(1 + 1.5 + 3)} \times 3.08$ = 0.84 m3

### How do you calculate sand in CFT?

Our total quantity of sand is 0.84 in m3, but in CFT(cubic feet) it will be ( 0.84 × 35.31) = 29.66 ≈ 30 CFT( cubic feet) [ Note: 1 m3 = 35.31 CFT or cubic feet ]

Quantity of aggregate is = ( Aggregate ratio ÷ Sum of all ratio) × Total volume of concrete = $\frac{3}{(1 + 1.5 + 3)} \times 3.08$ = 1.68 m3.

### How do you calculate aggregates in CFT?

We know, 1 m3 is equal to 35.31 CFT. Therefore, 1.68 m3 aggregate means 1.68 × 35.31 = 59.32 ≈ 60 CFT.

Example: 2

A section of footing is given below. Find out the quantity of cement sand and aggregates required for this footing.

Solution:

At first, we need to calculate the total volume of concrete required for this footing. The total volume of concrete is equal to the total volume of footing.

So, the total volume of concrete is = 1 × 7 × 6 = 42 cubic feet.

Dry volume of concrete will be = 42 × 1.54 = 64.68 cubic feet.

In the case of M20 concrete,

The Quantity of cement required for this footing is = $\frac{1}{(1 + 1.5 + 3)} \times 64.68$ = 11.76 cubic feet. Or, 0.33 in m3 [ Note: 1 m3 = 35.31 CFT or cubic feet]

The weight of cement = 0.33 × 1440 = 475.2 kg. Or, 475.2/50 = 9.50 ≈ 10 No.s bags.

Quantity of sand required = $\frac{1.5}{(1 + 1.5 + 3)} \times 64.68$ = 17.64 cubic feet or CFT .

The Quantity of aggregate required = $\frac{3}{(1 + 1.5 + 3)} \times 64.68$ = 35.25 CFT.

## Calculate the Quantity of Cement, Sand & Aggregate in M15 Concrete.

Now, we will calculate the quantity of cement and aggregate in M15 Concrete. Let’s take an example,

Example:

Let’s assume that the volume of total concrete(wet concrete) required for a particular work is 1 m3. Now find out the quantity of cement, sand, and aggregate.

Solution:

In the case of M15 concrete, the ratio of cement, sand, and aggregate is 1: 2: 4.

Dry volume of concrete = wet volume of concrete × 1.54

Hence, the dry volume of concrete is = 1 × 1.54 = 1.54 m3

The required quantity of cement is = (Cement ratio ÷ Sum of all ratio) × Total volume of concrete = $\frac{1}{(1 + 2+ 4)} \times 1.54$ = 0.22 m3

0.22 m3 cement means 0.22 × 1440 = 316.8 kg cement.

In general, each bag of cement weight is 50 kg.

So, the required number of cement bags are = 316.8 ÷ 50 = 6.33 ≈ 7 No.s.

Quantity of sand required = ( Sand ratio ÷ Sum of all ratio) × Total volume of concrete = $\frac{2}{(1 + 2 + 4)} \times 1.54$ = 0.44 m3

Our total quantity of sand is 0.44 in m3, but in CFT(cubic feet) it will be ( 0.44 × 35.31) = 15.53 ≈ 16 CFT( cubic feet) [ Note: 1 m3 = 35.31 CFT or cubic feet ]

Quantity of aggregate is = ( Aggregate ratio ÷ Sum of all ratio) × Total volume of concrete = $\frac{4}{(1 + 2 + 4)} \times 1.54$ = 0.88 m3.

We know, 1 m3 is equal to 35.31 CFT. Therefore, 0.88 m3 aggregate means 0.88 × 35.31 = 31.07 ≈ 32 CFT.

## Calculate the Quantity of Cement, Sand & Aggregate in M10 Concrete.

Now, we will calculate the quantity of cement and aggregate in M10 Concrete. Let’s take an example,

Example:

Let’s assume that the volume of total concrete(wet concrete) required for a particular job is 3 m3. Now find out the quantity of cement, sand, and aggregate.

Solution:

In the case of M10 concrete, the ratio of cement, sand, and aggregate is 1: 3: 6.

Dry volume of concrete = wet volume of concrete × 1.54

Hence, the dry volume of concrete is = 3 × 1.54 = 4.62 m3

The required quantity of cement is = (Cement ratio ÷ Sum of all ratio) × Total volume of concrete = $\frac{1}{(1 + 3+ 6)} \times 4.62$ = 0.462m3

0.22 m3 cement means 0.462× 1440 = 665.28 kg cement.

In general, each bag of cement weight is 50 kg.

So, the required number of cement bags are = 665.28 ÷ 50 = 13.3 ≈ 14 No.s.

Quantity of sand required = ( Sand ratio ÷ Sum of all ratio) × Total volume of concrete = $\frac{3}{(1 + 3 + 6)} \times 4.62$ = 1.386 m3

Our total quantity of sand is 1.386 m3 , but in CFT(cubic feet) it will be ( 1.386 × 35.31) = 48.93 ≈ 49 CFT( cubic feet) [ Note: 1 m3 = 35.31 CFT or cubic feet ]

Quantity of aggregate is = ( Aggregate ratio ÷ Sum of all ratio) × Total volume of concrete = $\frac{6}{(1 + 3 + 6)} \times 4.62$ = 2.77 m3.

We know, 1 m3 is equal to 35.31 CFT. Therefore, 2.77 m3 aggregate means 2.77 × 35.31 = 97.8 ≈ 98 CFT.

Types of Aggregates

Different Types of Cement Tests

## Advantages of Precast Concrete Piles

Advantages of precast concrete piles are as follows:

1. During concreting, the reinforcement which is used in the piles is not disturbed from its actual position.

2. Proper control in casting and curing can be exercised and if any defect after casting is noticed, it can be corrected before piles are used.

3. They can also be driven underwater.

4. Precast concrete piles are not affected by the chemical action of the subsoil.

5. They can be taking load immediately after their placing to their required place and no time is wasted.

6. Several piles can be manufactured side by side at a time, so its manufacturing cost is less than other types of piles.

## Disadvantages of Precast Concrete Piles

Following are the disadvantages of precast piles

1. Being very heavy, transporting, handling and driving theme is very hard.

2. extra steel must be provided near the top and bottom of the piles, in order to avoid the stresses developed during handling and driving.

3. The precast concrete piles can not be cast in a correct length unless trial bores are made. Therefore, it becomes very difficult to cut extra length, if the pile is casted longer than the required length.

4. It may break without proper handling and driving.

5. The pile length is also restricted depending on the mode of transportation available.

Difference Between Air-entrained and Lightweight Concrete

1. Concrete ingredients(cement, aggregate, water) are easy to get at any place.

2. The ingredients of concrete can be transported effortlessly anywhere.

3. Mixing and placing of concrete are easy.

4. The workability of concrete can be increased by increasing water and changing the proportions of concrete components.

5. Skilled workers are not required for mixing and placing of concrete.

6. It is a fire-resistant material.

7. The is high.

8. Concrete is a semi-liquid material, So it can be cast to get any needed shape.

9. Concrete is a long-lasting material.

10. The Concrete fairly acts as thermal insulation.

11. Deterioration of concrete is less.

12. In colour mixing, chemical changes usually do not occur.

13. Concrete has better water insulation compared to others.

14. The concrete maintenance process is very easy and the maintenance cost is low.

15. The compressive strength of concrete is very high.

16. Concrete can endure all weathering effects, so it is suitable for all seasons.

1. Once it gets hardened, it cannot be converted to another form.

2. The concrete construction is not suitable for extreme saline or acidic environment conditions.

3. It needs a few days to achieve its full strength.

4. Without using the reinforcement bar, the tensile strength of the concrete is negligible.

Slump Test

Causes of Deterioration of Concrete

Factors Affecting The Workability of Concrete

# 10 Way To Prevent of Concrete Deterioration

## How To Prevent Concrete Deterioration?

The following measures are taken to prevent deterioration of concrete:

1. From the consideration of permeability, the water-cement ratio is usually limited to 0.45 to 0.55.

2. The cement content should be such that it ensures sufficient alkalinity to prevent corrosion of reinforcement. For concreting under marine environment, minimum cement content of 350 kg/m or more is to be used.

3. The water-cement ratio and the cement content must provide enough paste to overfill the voids in compacted concrete.

4. Use of Portland slag cement or Portland pozzolana cement is advantageous for concreting in sea water.

5. Use of Portland cement having C3A content less than 5% is suitable for concreting under sulphate environment.

6. The super-sulphated cement provides acceptable durability against the acidic environment.

8. It is possible to attain a marked improvement in the quality of concrete by encouraging natural or artificial carbonation of the surface layer.

9. Deterioration of concrete can also be prevented by treating the concrete with solutions of suitable salts or even acids in minor concentration.

10. The durability of concrete can also be increased by impregnating the pores with a suitable polymer.

Causes of Deterioration of Concrete

Factors Affecting The Durability of Concrete

# Causes of Deterioration of Concrete

## Causes of Deterioration of Concrete

Deterioration of concrete is caused due to the influence of both external and internal agencies. The external or environmental agencies causing the deterioration of concrete includes:

• Weathering.
• Attack by natural or industrial liquids and gases.
• Acids in the form of water solution.
• Fertilizers, insecticides and certain organic compounds.
• Attack by biological agents.

The internal agencies responsible for the deterioration of concrete includes:

• Harmful alkali-aggregate reactions.
• Volume changes due to non-compatible thermal and mechanical properties of aggregates and cement paste.
• Presence of sulphates and chlorides in the ingredients of concrete.

8 Factors Influencing the Choice of Mix Proportions

How to Reduce Bleeding in Concrete

10 Way To Prevent of Concrete Deterioration

# 8 Factors Influencing the Choice of Mix Proportions

## 8 Factors Influencing the Choice of Mix Proportions

According to IS 456-2000 and IS 1343-1980, the designs of the concrete mix should be based on the following factors:

The grade designation gives characteristic compressive strength requirements of concrete. It is the major factor influencing the mix design

The concrete mix has to be designed for a target mean compressive strength which is somewhat higher than the characteristic compressive strength.

### 2. Types and Grades of Cement

The rate of development of compressive strength of concrete depends upon the type & grade of cement used. The choice of the type of cement depends upon the requirements of performance at hand.

Where very high compressive strength is required, Portland cement of grades 43 and 53 will be found suitable.

### 3. Maximum Nominal Size of Aggregates

The workability and compressive strength of concrete greatly depend upon the maximum size of aggregates. The workability increases with an increase in the maximum size of the aggregate.

On the other hand use of the large maximum size of aggregate, requires a smaller quantity of cement for a particular water-cement ratio. However, the smaller size aggregates provide a large surface area for bonding with the mortar matrix which increases the compressive strength.

### 4. Grading of Combined Aggregate

The grading of combined aggregate i.e., the relative proportion of the fine & coarse aggregates in a concrete mix is one of the important factors affecting the strength and workability of concrete. For dense concrete, it is essential that the coarse and fine aggregates be well grade.

### 5. Water-Cement Ratio

At a given age and under normal temperature, the compressive strength of concrete depends primarily on the water-cement ratio. The lower the water-cement ratio, the greater the compressive strength & vice-versa.

### 6. Workability

Insufficient workability of concrete may be liable for incomplete compaction of concrete which ultimately affects the strength, durability & surface finish of the concrete.

### 7. Durability

The durability of concrete is its ability to resist deterioration due to weathering action, chemical attack, abrasion etc. The requirements of durability are achieved by restricting the minimum cement content & the maximum water-cement ratio.

From the consideration of permeability, the water-cement ratio is usually restricted to 0.45 to 0.55. For a given water-cement ratio, the cement content should correspond to the required workability considering the placing conditions and the concentration of reinforcement.

In addition, the cement content is chosen to ensure sufficient alkalinity to provide a passive environment against the corrosion of steel.

### 8. Quality Control

The strength of concrete may vary from batch to batch over a period of time.    The source of variation in the strength of concrete may be considered due to the variation in the quality of materials, mix proportion, mixing equipment, supervision & workmanship. The factor controlling this variation is quality control. The degree of control is ultimately evaluated by the variation in test results.

Types of Concrete

# 4 Difference Between Air-entrained and Lightweight Concrete

## Difference Between Air-entrained and Lightweight Concrete

Following are the 4 difference between air-entrained concrete and lightweight Concrete:

### Air entrained Concrete

1. The concrete which is made by mixing a small quantity of air-entraining agent or using air-entraining cement is called air-entrained concrete.

2. It is made by mixing a small quantity of air-entraining agent or using air-entraining cement.

3. This concrete is particularly suitable for places where there is a greater chance of frost attack.

4. Its unit weight is less than the ordinary concrete but more than the lightweight concrete.

### Lightweight Concrete

1. The concrete whose density varies from 300 to 1800 kg/m is known as lightweight concrete.

2. It is prepared by adopting any more of the following measures:

• a) By cellular construction.
• b) By using no fines concrete.
• c) By using lightweight aggregates such as expanded clay, shale and slate, fly ash, blast furnace slag etc.

3. It is highly used as an insulator to the exterior wall of all types of buildings.

4. Its unit weight is less than air-entrained concrete.

Polymer Concrete

High Strength Concrete

6 Difference Between Prestressed and Reinforced Cement Concrete

# How to Reduce Bleeding in Concrete

## How to Reduce Bleeding in Concrete?

The tendency of water to rise to the surface of freshly placed concrete is called bleeding. Bleeding causes the formation of a porous, weak and non-durable concrete layer at the top. It also increases the permeability of concrete.

Bleeding can be reduced by adopting the following measures:

• Using pozzolanic materials.
• Proper proportioning of ingredients and uniform & complete mixing.
• Using air-entraining agents.
• Using finer cement.

Segregation of Concrete – 4 Causes and 5 Prevention

Method of Test For Bleeding of Concrete

# Method of Test For Bleeding of Concrete

## Method of Test For Bleeding of Concrete

This test determines the relative quantity of mixing water that will bleed from a sample of freshly mixed concrete.

### Apparatus

The apparatus used to conduct the bleeding test of concrete are:

1. A cylindrical container having inside diameter of 250mm, inside height of 280mm and capacity of 0.01m³(approximately).

2. A tamping rod made of steel of 16mm in diameter and 600mm long.

3. A pipette.

4. A graduated jar of 100cm³ capacity.

### Procedure

Following are the procedure for bleeding test of concrete:

A sample of freshly mixed concrete is obtained. The concrete is filled in the cylindrical container in equal five layers and each layer is tamped by tamping rod. The top surface is made smooth by trowelling.

The test specimen is weighted and the weight of the concrete is noted. Knowing the total water content in 1m³ concrete. The quantity of water in the concrete in the cylindrical container is calculated.

The cylindrical container is kept in a level surface free from vibration at a temperature of 27℃ ± 2℃. Water accumulated at the top is collected by pipette at regular interval till bleeding ceases. All the bleeding water is stored in a measuring jar. Then

Bleeding Water Percentage = (Total quantity of bleeding water/Total quantity of water in the sample of concrete)×100%

Segregation of Concrete – 4 Causes and 5 Prevention

# Difference Between Plasticizer And Superplasticizer

## Difference Between Plasticizer And Super Plasticizer

An admixture capable of reducing water requirements by more than 5% is classified as water reducer or plasticizer. Depending upon the degree of water reduction, the water reducers are categorized as normal water reducer, mid-range water reducer and high-range water reducers or superplasticizer.

The normal water reducer reduces the water content by 5 to 10%. The mid-range water reducer reduces the water content by about 10 to 15%. The high-range water reducer(HRWR) or superplasticizers are capable of reducing water content by about 20 to 40%.

The superplasticizers are principally surface reactive agents. They give a negative charge on individual cement particles such that they are kept in a dispersed or suspended state due to inter-particle repulsion. Thus they give high mobility to the particles.