Monday, 19 February 2018

Brief over view of Plain Cement Concrete (PCC)

P.C.C means plain cement concrete and its also recognized as pre-cast concrete, cement concrete (CC), binding concrete etc. It is formed by blending the cement, aggregate(coarse or fine ),sand and water in proper ratios. PCC is strong in compression but poor in the tension and shear. It's mostly found in foundation work and flooring in building.



Applicable tools for forming PCC:

Generally, the following tools are utilized for developing Plain Cement Concrete.
• Wooden or Steel rammer
• Mixture machine (if any)

Density of PCC:

The density of PCC usually remains at 50mm over Brick Flat Soling (BFS). If BFS is not applied underneath PCC then the thickness should remain at 75¬mm. If the PCC is applied in car park area then the thickness should remain at 75mm over BFS.



Ratios of materials for PCC:

By volume, the ratio of cement, sand and brick chips in foundation or basement is 1:3:6. But, in car park area, the ratio changes to 1:2:4.

Placing and Compaction of PCC:

• Ensure brick soling/sand bed level for PCC is perfect.
• Develop form work for PCC with wooden plank according to stipulated dimensions.
• Cleanse dust or foreign or loose earth from concreting area.
• Wrap the bed of PCC with polythene.
• Produce level pillars of fresh concrete in the area at proper gapping but not in excess of 2m c/c both ways.
• Set the concrete smoothly (don’t through) from one side. Apply the mixed concrete within 45 minutes as soon as the water is mixed.
• The compaction and finishing of PCC should be done with wooden rammer.
• Create the surface of PCC coarsen for joining future work prior to concrete gets solidified.

Curing of PCC:



After PCC is placed for 24 hours, wet the concrete surface by drenching with water or by wrapping with moist gunny bags minimum 7 days.



Examining and Inspection:

• Verify the dimensions of form work of PCC prior to mixing concrete.
• Examine whether polythene sheet is placed over PCC bed.
• Verify the concrete slump (highest slump should have been 75mm)
• Ensure the thickness level of PCC prior to casting by providing steel pegs in concreting area or level pillar of fresh concrete at proper spaces.
• Verify the finish level of PCC by thread fixing with nails in form work.
• Make sure that the concrete is placing smoothly.

Article Source : http://www.acivilengineer.com

Friday, 16 February 2018

Thumb rules for working out quantities in residential buildings

Professional estimators have the ability to measure the quantities of concrete, steel, brickwork, plaster and finishing material depending on the total built-up area of a residential building without noticing the building plans.



Given below, the step-by-step guidelines on how to determine the quantities for a residential building having roughly 1 lakh square foot built-up area.

Concrete- Roughly 4500 cum of concrete will be essential for the structural frame of the building. The thumb rule should be followed as 0.045 cum of concrete per square foot of built-up area. This quantity may rise to some extent for a building with basements as supplementary concrete would go in the raft, retaining walls and to the ramps to the basement.







Rebar- Roughly 540 tons of rebar will be essential. The thumb rule should be followed as 120 kg of rebar per cum of concrete. For highrise buildings, there should be more steel in the colums and the amount of steel per cum of concrete would raise with the height of the building.

Brickwork - Approx 1.3 lakh sq feet of wall would exist in the building with 1 lakh square feet area. Though, the total area of the walls would mostly base on the size of rooms.

Plastering and Paint Area – It is roughly 3 times of the brickwork area . It should be kept in mind that ceiling and staircase plastering are also included.

These numbers are applicable to large residential towers and not intended for small housed and bungalows. It is advised to use these numbers cautiously as they may fluctuate for your specific project.

Article Source : http://india-construction.blogspot.in

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Published by
Rajib Dey
email : rajib_dey@aol.com
website : www.sketchup3dconstruction.com (construction related articles & news)

Monday, 12 February 2018

Details of plinth beam in construction

A plinth alias tie beam stands for a beam that is built up at plinth level among foundation footings and superstructure. The objective of plinth beam is to resist the splitting of column because of load generating from above. It offers extra strength with respect to settlements of the building and earthquake damages. Plinth beam in a frame structure connects all the columns to minimize the length of the columns and thus decreases their effective length and slenderness. Brick or stone masonry is normally constructed underneath the plinth beam.


Plinth beams are generally set up in the situation where the foundations are little deeper and consequently they perform like a bracing or tying element. Plinth beam helps in evading differential settlement in a building because all the load of the wall is borne by the plinth beam below.


In a skeletal system alias a framed structure; plinth beam should constructed initially as soon as the foundation is set up. As the finish floor level of the ground floor is retained higher as compared to the ground level; the empty gap and void is stuffed with a compacted soil to produce a secure surface for the floor to be built up.
Image Source : http://homeinabox.us



The plinth beam is normally expected to be strong enough for bearing the superimposing brick walls efficiently tying the columns and the structure. As per the structural requirement of a building; plinth beam can either be reinforced or non-reinforced.
Plinth beam is very useful in earthquake prone areas. Besides, it is also built up over the natural ground.
Strength of plinth beam concrete shall not be smaller than 20MPa. If concrete is blended by hand, then additional 20% cement should be included to the mixture.
A least depth of plinth beam is 20cm while its width must be similar with the width of final course of the foundation.
It is suggested to arrange two bars having least diameter of 12mm at the bottom of the beam. In the same way, two bars having least diameter of 10mm must be arranged at the top of the plinth beam.

Reinforcement bars should have been safeguarded with 25mm concrete cover. For stirrups, stirrup diameter should be minimum 6mm and a spacing of 15cm is recommended.
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Published by Rajib Dey
Senior Content Editor
www.sketchup3dconstruction (an information hub for civil engineering & sketchup)
Email : globalrajib71@gmail.com

Tuesday, 6 February 2018

Concrete Design for the Civil PE and Structural SE Exams, 2nd Edition

C. Dale Buckner PhD PE has written an exclusive e-book alias Concrete Design for the Civil PE and Structural SE Exams, Second Edition. The book briefly sheds light on concrete design methods and standards.

This book can be used side by side with PPI’s Civil Engineering Reference Manual (CERM), Structural Depth Reference Manual (CEST), or Structural Engineering Reference Manual (STRM). CERM, CEST, and STRM belong to the fundamental texts for all who are preparing themselves for the civil PE or structural engineering (SE) exams, and each book introduces the basic concepts and most common applications associated with concrete design. It is indispensable that this book should have been utilized with the American Concrete Institute’s Building Code Requirements for Structural Concrete (ACI 318) and Commentary (ACI 318R).



Concrete Design for the Civil PE and Structural SE Exams demonstrates the concrete design and analysis methods very much required by the civil and structural engineering students.  The book’s 12 chapters offer a brief and precise review of concrete theory, code application, design principles, and structural analysis. The 51 example problems present how to employ concepts, codes, and equations, as well as more than 40 figures and tables present crucial support material. A complete nomenclature list describes the industry-standard variables and symbols which are provided in each chapter.



This book comprises of code references to make you acquainted with exam-adopted codes, like ASCE7 and ACI 318. It also contains 35 multiple-choice problems and 2 scenario-based design problems to improve your problem-solving skillfulness. Each problem’s complete solution allows you to verify your solving approach. On exam day, the comprehensive index of this book can be applied to instantly discover vital codes and concepts.

Civil Engineering Book


The includes the following topics
• Columns and Compression Members
• Continuous One-Way Systems
• Design Specifications
• Development of Reinforcement
• Flexural Design of Reinforced Concrete Beams
• Materials
• Pre-stressed Concrete
• Seismic Design of Reinforced Concrete Members
• Serviceability of Reinforced Concrete Beams
• Shear Design of Reinforced Concrete
• Two-Way Slab Systems

Go through the following link to purchase the book online from amazon.
https://www.amazon.com/Concrete-Design-Civil-Structural-Exams/dp/1591264731

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Published by
Rajib Dey
email : rajib_dey@aol.com
website : www.sketchup3dconstruction.com (construction related articles & news)

Wednesday, 31 January 2018

Types of aggregates on the basis of grain size & volume weight

Aggregates alias construction aggregates are made of materials like sand, gravel, crushed stone, slag and recycled concrete. The standard types of aggregates are granite aggregates, gravel aggregates, limestone aggregates, secondary aggregates and slag aggregates. The aggregates are obtainable in different sizes like 10 mm, 20 mm, 30 mm. It is mostly found in construction industry for erecting buildings, roads along with water filtration and sewage treatment processes.



Aggregates stand for the static materials which are blended in fixed ratios with a Binding Material to form concrete.

The aggregates can be applied as fillers or volume increasing components as well as liable for maintaining strength , solidity and longevity of the concrete.

Qualities of Aggregates



The most vital properties of aggregate are given below :-

1. It should be chemically inert that means they should not respond to cement or any other aggregate or admixture.
2. It should contain adequate rigidity to get rid of scratching and erosion in the hardened state.
3. It should contain enough toughness to tolerate impact and vibratory loads.
4. It should be sufficiently strong to withstand compressive and normal tensile loads in ordinary mixture.
5. There should be no impurities, inorganic or organic in nature, which may provide significant impact on its quality.
6. It should have the capability of developing an easily executable plastic mixture on amalgating with cement and water.

Image Source : https://cormsquare.com



Categorization of aggregate

Based on the grain size, origin and volume-weight, the aggregates are categorized as follows:

Types of aggregates on the basis of Grain Size

It is mostly recognized classification method, where there are two types of aggregates like fine and coarse.

(i) In the Fine Aggregates, the grain-size remains among 4.75 mm and  0.15 mm. Conversely, these go through from sieve having mesh size of 4.75 mm and are kept on a sieve of 0.15 mesh size.
Sand is considered as globally recognized natural Fine Aggregate.

(ii) Coarse Aggregates: These types of aggregates are kept on the sieve of mesh size 4.75 mm. Their upper size is normally around 7.5 mm. Gravels obtained from river bed are treated as the best coarse aggregates in the formation of Common Concrete.

Under these situations, if they are not accessible easily, appropriate rock types are crushed to the preferred particle sizes for forming coarse aggregates.

Types on the Basis of Density

Based on the weight per unit volume, there are three types of aggregates.

(i) Standard or Normal: These types of aggregates provide strength and weighting to the Concrete of around  2300 to 2500 kg/m3.

Gravels, Sand and Crushed stone are considered as Standard or Normal Aggregates.

(ii) High-Density Aggregates:  These types of Aggregates are utilized in standard proportions given in heavy weight concretes. Such concretes are mostly found as shields against X-rays and radiationsin atomic power plant.

Examples: Baryle – a natural mineral containing specific gravity of 4.3.

Concretes with such aggregate normally contain weight over 4000 kg/m3.

(iii) Light weight Aggregates. These comprise of natural and artificial materials with very low density in order that the consequential concrete has light weight, normally within a range of 350 to 750 kg/m3. They are particularly utilized in sound proofing and fire proofing constructions. They are also mostly suitable for developing light weight Pre-Cast concrete blocks.

For more details, go through the following construction article.
https://civilguides.com/aggregate-definition-aggregates-types/

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Published by
Rajib Dey
email : rajib_dey@aol.com
website : www.sketchup3dconstruction.com (construction related articles & news)

Friday, 12 January 2018

Basic guidelines for Brick Masonry Constructions

While going to develop brick masonry, the points given below should be taken into consideration :-

1. It is recommended to use standard quality bricks which contain consistent color. Besides, bricks should be burnt perfectly and contain perfect shape and size.

2. Prior to utilize the bricks in masonry, they should have been drenched in water for 2 hours to avoid water consumption from the mortar.



3. Bricks should be placed with the frog pointing upward.

4. The brick wall should be built up from the end or corner.

5. Brick courses should have been correctly horizontal.

6. A plumb-bob is used to verify the verticality of the wall on a regular basis.



7. Mortar should be applied on the basis of the specification.

8. Whenever work is finished brick masonry should be discarded with toothed end.

9. Refrain from utilizing brick bats.

Image Source : http://www.akbworks.com


10. Walls should have been lifted up homogeneously. The variation among adjoining walls should not be over 1 m. In a day no wall should be lifted up by above 1.5 m.

11. To provide perfect key for plastering or pointing, the face joints should be lifted up to a depth of 12 to 20 mm, as soon as the mortar is green. If there is no plastering or pointing, face joints should be fixed flush and finished precisely.



12. Holdfasts for doors and windows should be set in brick masonry along with cement mortar or concrete while building up the wall independently.

13. Brick masonry should be cured frequently for 2 weeks.

14. Single scaffolding should have been utilized for the formation of brick work at higher levels.

Source : http://www.civilengineeringx.com

Tuesday, 9 January 2018

The process and benefits of concrete resurfacing


It is found that old concrete suffers from cracks, surface discoloration, or surface imperfections. In order to enhance the appearance of the concrete, old concrete should be removed and replaced properly. Here, lies the importance of concrete resurfacing.


Concrete resurfacing refers to a process with which tone or injured concrete floor or pavement surfaces are cleaned, repaired and coated with a new surface to make them usable again devoid of reconstructing the entire structure.

Various steps like cleaning, repairing the cracks, repairing the holes, coating the surface, coloring and sealing, curing are involved in concrete resurfacing.

Image Source : https://www.cnysealing.com



Benefits of Concrete Resurfacing

1. The concrete resurfacing is undertaken for the maintenance and durability of the surface. It facilitates resisting cracks for a prolonged period and reduces the chances for development of potholes (In the case of driveways).

2. The concrete contains a light color that helps in managing the temperature as well as delivering a convenient cooling effect throughout summer seasons.

3. Concrete resurfacing is now accomplished by staining with different types of color to apply artistic beauty to the surface.

4. Diverse color options exist in the concrete resurfacing option. It can provide a nice appearance for the home exterior.

5. The elimination of snow from the concrete surface becomes simple with regard to any other surface.


Drawbacks of Concrete Resurfacing
1. If the placement over surface is inappropriate along with the assessment of the present condition, the concrete resurfacing will not be successful. It may cause illustrating the cracks on the surface. To resolve this issue, eliminate the pavement fully and develop a new surface.

2. It is not cost-effective for bigger areas.

For more information, go through the following construction article
https://theconstructor.org/practical-guide/concrete-resurfacing-repair-concrete-floor-pavement-surfaces/20597/

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Posted By Rajib Dey
Website : www.sketchup3dconstruction.com
 Email : rajib_dey@aol.com

Brief over view of Plain Cement Concrete (PCC)

P.C.C means plain cement concrete and its also recognized as pre-cast concrete, cement concrete (CC), binding concrete etc. It is formed by...