Some vital tests to check the quality of concrete

Concrete is mainly a composite material that comprises of fine & coarse aggregate, water, cement, and admixtures.

To obtain high-quality concrete, the sample should be examined thoroughly to ensure whether it is formed according to requirement or not. If the test for concrete is not conducted, the following problems will occur :-

• Cracks and voids in the finished concrete.
• The concrete of Low compressive strength.
• Bleeding

Given below, the details on some vital tests of concrete:

1. Workability test
2. compressive strength test
3. Non-destructive test
4. Destructive test
5. Durability test

WORKABILITY TEST: Workability test plays a crucial role since it is associated with the strength of concrete. Workability means the capacity to fill the mould perfectly with the vibrator but the quality of concrete is not affected. The Workability of concrete is calculated with the following test:

• SLUMP TEST
• VEE-BEE TEST
• COMPACTING FACTOR TEST

Compressive strength of concrete: The concrete can’t sustain the compressive load. So, it becomes essential that any concrete member could withstand a good amount of compressive load.

Under this test, the maximum compressive strength of the concrete sample is ascertained after 28 days of curing. Based on the standard code of India, 150 mm concrete cubes are utilized in this test. Under this test, the concrete sample should be immersed for 28 days and after each 7 days water should be changed. After 28 days of curing, the concrete specimen is arranged on the machine plate.

Now load is provided slowly to the specimen unless the collapsing of the concrete cube occurs. Destructive and Non-destructive Test of Concrete These tests are carried out to find out the compressive strength of the existing concrete structure where the required concrete sample is not available.

This types of tests are conducted with the destructive or Non-destructive way.

If Non- destructive way is followed, compressive strength should be established devoid of affecting the structure or any concrete member. The Non-destructive test is conducted on the following ways :

• Rebound hammer test
• Penetration and pullout techniques
• Surface hardness test
• Radio-active method

Most common Destructive tests are as follows:

• Concrete core test
• Cube test
• Tensile strength test

Durability Test: With the purpose of maintaining the sustainability of concrete, the stability of concrete is required. To enhance the stability of concrete, it's vital that concrete should contain the following qualities :

• Water resistance
• Chloride attack resistance
• Resistance to infiltration of water.

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Published By
Rajib Dey
www.constructioncost.co
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What should be the qualities for becoming a successful civil engineer

In order to become a successful civil engineer, the following qualities are essential :-

1. TESTS OF BUILDING MATERIALS: An efficient civil engineer should be well versed with various test methods of building materials. Given below, the details of some crucial test methods :-

Concrete Test: Slump test, compression test, split tensile test, soundness etc.
Soil Test: Core cutter test, compaction test, sand replacement test, tri axial test, consolidation test etc.
Bitumen Test: Ductility test, softening point test, gravity test, penetration test etc.

2. EXAMINATION OF SOIL: Prior to build up a construction, different types of soil tests are accomplished to define the settlement and constancy of soils. Therefore, as a civil engineer, one should possess adequate knowledge with these tests to carry on at the job site.

3. APPLICAIONS OF SURVEYING INSTRUMENTS: Each civil engineer should have clear conception on how to apply various surveying instruments like the total station, theodolite etc. These instruments are specifically designed for marking and measurements.

4. STANDARD CODES USED IN CONSTRUCTION: Each country should contain their standard safety specifications (eg: Is Code) for construction associated works. The construction works of new buildings should abide by the rules and processes indicated in the standard codes. if not, there are chances for collapsing of the structure any time.

5. BAR BENDING SCHEDULE: Bar bending schedule is a vital chart for civil engineers. It offers the reinforcement calculation of RC beam like cutting length, type of bending, the length of bending etc.

6. DRAWING AND DESIGN: Drawing and design are considered as the elementary part of a running project. It offers all the necessary specifications of that project. Each site engineers should possess the quality for evaluating such drawings and designs.

7. COMPUTATION AND BILLS: A civil engineer should have the skills to produce the estimation and bills in a construction project.

8. QUALITY CONTROL: With proper quality control, the profit of the project is raised and the cost is decreased. Therefore, a engineer should be well versed with quality control process.

9. ON SITE MANAGEMENT: A engineer should have adequate knowledge with form-work, concreting, safety measures etc.

10. COORDINATION WITH LABOR: As a civil engineer, one should know how to manage the labors in a job site.



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Published By
Rajib Dey
www.constructioncost.co
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What should be the qualities of a qualified civil engineers

1. TESTS OF BUILDING MATERIALS:

A qualified civil engineer should be well familiar with various tests of building materials. Given below, detailed lists of some vital tests.

 Concrete Test: Slump test, compression test, split tensile test, soundness etc.
 Soil Test: Core cutter test, compaction test, sand replacement test, triaxial test, consolidation test etc.
 Bitumen Test: Ductility test, softening point test, gravity test, penetration test etc.

2. Examination OF SOIL:

Prior to develop a construction, different types of soil tests are done for finding out the settlement and strength of soils before starting a construction. Therefore, a civil engineer must contain sound knowledge regarding these tests which are carried out at the jobsite.

3. Application OF SURVEYING Tools:

A civil engineer should be well versed with utilizing various surveying instruments like the total station, theodolite etc. These instruments can be applied for marking and perfect measurements.

4. STANDARD CODES utilized IN CONSTRUCTION:

Each country contains their own standard safety specifications (eg: Is Code) for performing various activities associated with construction. There are various types of rules and methods in the standard codes and these are followed to build up new construction. If not, there are risks factors for collapsing of a structure.

5. BAR BENDING SCHEDULE:

Bar bending schedule is considered as a crucial chart for civil engineers. It helps to make the reinforcement calculation for RC beam that ranges from cutting length, type of bending, the length of bending etc.

6. DRAWING AND DESIGN:

Drawing and design are considered as the pillars of a project in-progress. It offers all the necessary specifications of that project. Each site engineers must have the capability to efficiently analyze such drawings and designs.

7. ESTIMATION AND BILLS:

A civil engineer should be able to prepare estimation and bills toward a construction project.

8. QUALITY CONTROL:

Quality control maintains the profit of a project by lessening the additional costs. Therefore, a civil engineer should contain the fundamental knowledge of quality control.

9. ON FIELD MANAGEMENT:

A civil engineer should have clear ideas on form-work, concreting, safety measures etc.

10. COORDINATION WITH LABOR:

A civil engineer should have the capability to manage labors efficiently in a jobsite.

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Published By

Rajib Dey

www.constructioncost.co

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Detailed methods for slump test to check the consistency of fresh concrete

This construction video briefly explains the importance of Slum Test and how it is used to examine the workability and conformity of fresh concrete.

The term ‘Slump’ can be defined as following two ways :-
1. A measurement of workability or fluidity of concrete
2. An indirect measurement of the conformity or rigidity of the concrete

Slump Test refers to the way of availing the conformity and & workability of fresh concrete. It is also utilized indirectly as a way of verifying whether exact amount of water is added to the concrete mix or not.

The test computes consistency of concrete in that particular batch. Consistency means the smoothness with which concrete flows. It is utilized to specify degree of wetness.

It belongs to the physical specifications of concrete that can impact the finesse, strength and durability.

ASTM C143 - Standard Test Method for Slump of Hydraulic-Cement Concrete.

It stands for a test necessary for passing the American Concrete Institute (ACI) Field Technician Certification Program -- "Concrete Field Testing Technician—Grade I."

A Concrete Field Testing Technician—Grade I refers to an individual who has validated the knowledge and capacity to properly execute and record the results originated from seven basic field tests on freshly mixed concrete.

The program needs a working knowledge of the various ASTM test methods and practices which are described below:

• C1064/C1064M - Temperature of Freshly Mixed Hydraulic-Cement Concrete
• C172 - Sampling Freshly Mixed Concrete
• C143/C143M - Slump of Hydraulic-Cement Concrete
• C138/C138M - Density (Unit Weight), Yield, and Air Content (Gravimetric) of Concrete
• C231 - Air Content of Freshly Mixed Concrete by the Pressure Method
• C173/C173M - Air Content of Freshly Mixed Concrete by the Volumetric Method

Watch the following video to view the detailed slum test process.

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Published By

Rajib Dey

www.constructioncost.co

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Mix Design On The Basis Of Dry Condition

Ascertain or Identify Slump Value

The initial step is to identify the lowest and highest limit for slump of concrete that has been utilized. Often the designer identify slump for concrete mix, this is correctly based on some conditions, otherwise if the value of slump is not indicated Table 1 is applied to find out the lowest and highest slump value on the basis of the type of structure.

Note: The value of (Table 1) is dependent on applying vibrator for compaction of concrete, if there is other method for compaction like a tamping by rods or other method add (2 cm) for every selected value from table 1.

Step 2: Ascertain or State Maximum Aggregate Size

Highest Aggregate Size is considered as the most vital data to be ascertained or identified for their mix design. This value is acquired from sieving analysis test result of coarse aggregate. Coarse aggregate must be examined prior to utilize in concrete mixture preparation. This value is accessible even for comprehensive mix design process.

Value of Maximum Aggregate Size must be examined with the following three equations:

(a): Highest Aggregate Size must be identical or lesser than 1/5 (lowest distance among form work side).

(b): Highest Aggregate Size must be identical or lesser than 1/3 (thickness of concrete member).

(c): Highest Aggregate Size must be identical or lesser than 3/4 (slightest distance among reinforcement).

Note: Point (c) is very vital in checking process as if the aggregate size exceeds the spacing of reinforcement while casting, concrete fails to pass the rebar cage. It signifies that passing ability of concrete is considerably reduced.

To read the complete article, visit ge4c.com

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Published By

Rajib Dey

www.constructioncost.co

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