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Saturday, December 16, 2017

Brief overview of concrete mix ratio

If cement is blended with sand, stone/aggregates and water, a paste will be developed and it can be applied to stick the building materials collectively. This paste is known as concrete.

The ration upon which the cement, sand, stones or aggregates are amalgamated, defines the strength of the concrete mix. Depending on these ratios, different types of concrete grades are accessible in the market. These concrete grades range from M10, M20, M30, M35, etc.

“M” denotes “mix”. Mix characterizes concrete with indicated ratios of cement, sand and aggregate. And the number after “M” denotes compressive strength of that concrete mix in N/mm2 after 28 days. As for instance, for M30 grade of concrete mix, its compressive strength after 28 days should have been 30 N/mm2.
Concrete mix ratio table
Given below, the standard chart table that displays different grades of concrete mix design together with their relevant ratios of cement, sand and aggregates required.
It is found that volume of sand is always retained half of that of aggregates in these standard mix designs. These proportions can be estimated and sustained with buckets or some other standard cubes which are easily utilized during the project. It is essential to keep up uniformity in each and every concrete mix produced throughout the entire project.
The site engineer/supervisor should take the responsibility to examine and implement it.
Water content ratio in concrete mix: The strength & adaptability of concrete is mainly dependent on water content. The adaptability of concrete (more fluid) will be increased with the higher quantity of water but it will decrease the concrete strength.
Contrarily, if the amount of water is low, adaptability of water will also be decreased. So, it becomes complicated to arrange such concrete in the structure. Required amount of water may differ for same volume of concrete for different grades of concrete. So, equilibrium should be maintained in the construction site throughout concrete mixing.

Video SourceCivil Engineering

Published By
Rajib Dey

Friday, December 15, 2017

Some useful civil engineering notes

This construction video tutorial is very useful for civil engineering students as it contains 10 objective types of questions on civil engineering and their solutions.

Some of the sample questions & their answers are given below :-

As per pertinent IS code, the weight of the timber will be treated as perfect if there is 12% moisture content in it.

The strength of the timber will be optimal if applied load is parallel to grain.

A standard brick should not engross water by weight in excess of 20% (after immersed in water for 24 hours)

When ‘p’ denotes the standard consistency of cement, 0.85 percent water is utilized in performing the initial setting time test on cement.

The lime mortar is normally formed with hydraulic lime.

The compressive strength of a standard good 1:3 portland cement – sand mortar after the completion of 3 days of curing, should not be under 175 kg/cm2.

The split tensile strength of M15 grade concrete is 15 to 20% of its compressive strength.

For brief explanation, watch the following construction video tutorial.
Video SourceTechnical Atyachar

Published By
Rajib Dey

Thursday, December 14, 2017

How to resolve issues prior to foundation design

To make a perfect foundation design, the following vital points should be taken into consideration:-

Make sure that the foundations are maintained as extremely shallow, suitable with atmospheric impacts and strength of the surface soil; specifically in flooded ground. Excavation in fatally flooded ground seems to be costly and slow.

Get rid of costly and complicated shuttering details specifically in hardened rafts. Proper care must be taken to examine the build aptitude.

The economics of the design can be significantly impacted with various factors like drop in the piling costs, upgrading in ground treatment, progression in soil mechanics, etc and various standard solutions are now obsolete. So, it is necessary to evaluate construction costs and methods on a regular basis.

Designers should be well versed with the presumptions provided in design, the inconsistency of ground conditions, infrequent inapplicability of refined soil analyses and the utility of construction.

Make proper evaluation to check the consistency of the soil.

Impact of construction on ground properties, i.e. vibration from piling, degradation of ground disclosed with excavation in unfavorable weather conditions, deduction of overburden, seasonal difference in the water-table, compaction of the ground through construction plant.

Impact of deviating shape, length and inflexibility of the foundation, and the requirement for movement and settlement joints.

Consequences on finished foundations with sulfate attack on concrete, ground movements because of frost heave, reducible clays, and the impacts of trees; also alterations in local environment, e.g. new construction, re-routing of heavy traffic, foundation of plant in adjacent factories inducing impact and vibration.

Rapid but costly construction may be more cost-effective as compared to low-cost but slow construction to clients requiring quick return on capital investment.

Impact of new foundation loading on existing nearby structures.
To get more information, go through the following construction video Civilblog.Org
How to resolve issues prior to foundation design
Published By
Rajib Dey

Wednesday, December 13, 2017

Comparison between OPC and PPC (fly ash based cement)

OPC 53 Grade Cement:OPC (Ordinary Portland Cement) belongs to the basic form of cement and it is formed with 95% cement clinkers and 5% gypsum.

Gypsum stands for an additive and it’s objective is to enhance the setting time of the cement to a executable 30 minutes or more.

OPC Cement provides high compressive strength at initial phases and at 28 days. A 53 Grade cement provides equal to 70 MPa strength across a minimum 53 MPa stated by BIS. Therefore, fly ash can also be blended (minimum 20% by weight of cement) in concrete as part replacement of cement at jobsite.

Due to this the material cost of concrete is saved significantly as well as durable properties can be maintained because of pore refinement (Less porous concrete).

If the concrete is formed in this way, the adaptability of concrete is enhanced greatly and it leads to higher strength in due course.

Recommended use for OPC 53 Grade Cement:
OPC 53 Grade cement is normally mostly suitable for Structural Concrete or Reinforced Concrete Works (like Columns, Beams, Slab etc.,).
PPC (Fly Ash Based) Cement: Alternatively, PPC (Portland Pozzolana Cement) is formed with 75 – 77% cement clinker, 20% flyash and 3-5% gypsum.
Recommended use for PPC: Flyash based cement (PPC) will be effective for brick masonry, plastering, tiling and waterproofing works. In these works, strength is not a vital factor. PPC is more beneficial as compared to OPC because PPC contains slower rate of heat of hydration.
Thus PPC is likely to less cracks & shrinkage), superior workability and finishing (because fly ash based cement are circular in shape and thinner in size).
Comparison between OPC and PPC (fly ash based cement)
Published By
Rajib Dey

Tuesday, December 12, 2017

EngiSSol 2.0 is a useful software for structural analysis

EngiSSol has developed 2D Frame Analysis Dynamic Edition. This construction program applies improved finite elements (beam elements) with the purpose of carrying out static and dynamic analysis of beams, frames and trusses.

It is very recognized due to it’s simple interface and smooth customization.

Analysis features:
• Employs exceedingly flexible, general, finite element method
• Perform static and dynamic analysis of multi span beams, 2D trusses and 2D frames
• Modal analysis and eigen values estimation
• User controlled damping coefficient
• Mode superposition method useful for making estimation of the dynamic response
• Automatic formation of constant mass matrix (Engissols patent)
• Completely customized multi-step dynamic analysis
• User controlled step and time parameters
• Definition of time-dependent loading on elements and nodes
• Infinite number of Nodes and Beams
• 3 Degrees of freedom per Node, 6 per Beam
• Compatible with all leading measure units
• Different types of boundary conditions (fixed, rollers, etc. )
• Translational and rotational spring supports
• Initial displacement and speed conditions
• Exceedingly easy model formation. It is not necessary to initially specify nodes and then elements, nodes are created automatically
• Consideration of thermal loads
Click on the following link to download the demo version Www.Cesdb.Com

EngiSSol 2.0 is a useful software for structural analysis

Published By
Rajib Dey

Monday, December 11, 2017

How to control or minimize segregation in concrete

Segregation in concrete refers to partition of concrete components due to inconsistency of concrete mix. The flow test can easily represent the bond of the concrete mix.

If the concrete is not integrated, the major particles of aggregate will be detached and will proceed towards the periphery. Another type of segregation occurs if concrete mix is provided on a wet surface. A cement particle generally moves from the center of the concrete mix and gives up the coarser material behind. Segregation is not calculated in qualitative terms but a knowledgeable professional can easily locate it.

A segregated concrete contains a variable strength and comparatively tends to cracking and leakages from the concrete. So, proper care should be taken to get rid of segregation in concrete to enhance the longevity of your structure.

Given below, some useful tips to avoid segregation in concrete:

01. The design of the concrete mix should be perfect with ideal quantity of water i.e. not too wet nor too dry.
02. Ensure the concrete is blended properly at the accurate speed in a transit mixture for relatively two minutes. Verify the performance of mixer on a daily basis regarding adequate equality of distribution of components in each batch.
03. Transmit the concrete mix properly. Select the perfect route through which the transportation of concrete mix can be done quickly.
04. Arrange the concrete in its final position rapidly. Never pour a concrete from greater heights.
05. Formwork should have been water resistant in order that paste should leakage from the forms. Check that formwork is not vibrated.
06. Ensure that concrete should not be streamed.
07. The vibrator should have been used properly and not to be utilized for extending a heap of concrete over a greater area.
08. Vibrate the concrete for just the exact time-not too long, not too less.
09. Employ chemical admixtures like air entraining agent in the mix. Entrained air helps in minimizing the possibility of segregation.
10. If any segregation is found in concrete, remixing should be performed to sustain it’s consistency.
How to control or minimize segregation in concrete
Published By
Rajib Dey

Friday, December 8, 2017

How to calculate or analyze the rates of cement, fine & course aggregates in a foundation construction

In this construction video tutorial, one will learn how to work out or analyze the rates of cement, fine aggregates, course aggregates in a foundation construction.

Assume, the length of the foundation is 80 ft and width is 30 ft. The thickness of the foundation is taken as 9 inches. M7.5 concrete grade is used with ratio 1:4:8. (cement : sand : aggregate).

Initially, you have to determine the volume with the following formula :-

Volume = Length x Width x thickness = 80 x 30 x 0.75 (as 9 inches is equal to 0.75 feet) = 1800 cft

It is the wet volume and you have to convert it to dry volume with the following method :-

We know that in measuring unit cubic meter or cubic feet, 54% volume is increased from wet to dry in concrete. To convert from percentage to decimal, just divide by 100 i.e. 1+84/100 = 1.54

So, dry volume = 1800 x 1.54 = 2772 cft

To calculate the quantity of cement, the following formula is used :-
Cement = Ratio x Volume/Sum Of Ratio = 1 x 2772/13 = 213.23 cubic feet
As 1 bag of cement = 1.28 cubic feet
In order to convert it to bags, just divide it with 1.25 i.e. 213.23/1.25 = 171 bags.
Similar formula can be used for calculating the rates of sand and aggregates.
Watch the following video to learn the process for calculating the rates of sand and aggregates.

Published By
Rajib Dey

Thursday, December 7, 2017

Details of slab reinforcement on the basis of bar bending schedule

This construction video provides detailed information on slab reinforcement that is created with bar bending schedule (BBS).

Slab reinforcement stands for the method that is undertaken to bend reinforcing steel and transform into shapes necessary for building up reinforced concrete structure.

Bar bending schedule (aka schedule of bars) belongs to a list of reinforcement bars, a specified RCC work item. It is demonstrated in a tabular form for smooth graphical reference.

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Published By
Rajib Dey

Wednesday, December 6, 2017

A Roofing Cost Estimator

A roofing cost calculator generally calculates the close estimate of roofing costs for any new or renovated home. It is seen that the cost of roofing in any kind of homes is the most expensive one and its ups and down depends on the materials, labor and roofing pitch.

This kind of calculator calculate the overall cost of roofing with the cost of labors, materials and warranty for any kind of roofing such as 3-tab asphalt shingles, architectural and superior composition shingles, PVC, TPO, EPDM rubber, built-up roofs, cedar shakes and shingles, clay tiles, natural slate and metal roofing.

Roofing is generally calculated and measured as per squares and a square of roofing is the amount of roofing material that is needed to cover 100 square feet. But the thing is not easy as there are different kinds of roof pitches and dormers and the measures are not same for all. So it is a good idea to make an estimate with the help of supplier or roofing contractor.

There are some roofing calculator can be found in the market that will help to calculate the exact roofing cost for a new home or a renovating home, it is usually supply a rough estimate that can be compared with the roofing contractors.

Cost: The prices are generally depends on the average roof placement costs in different countries. The price of different materials highs or lows as per their quality and the price of the labor depend on the quality of roofing materials. To make the ultimate pricing details, calculate with the chimneys or floors or levels where the flooring needs to be done.

Pitch: The increasing pitch of the floor highs the labor of installing roofs and it affects replacement roof costs and new home costs than any other area. Roof pitch generally implied through a number over a number and the higher number is the sharper pitch. The roofing contractors take price as per the weight of shingle and the roof pitch as the sharper pitch and heavier shingle make their job difficult though in case of look the sharper pitch and heavier shingle make the roof structure beautiful.

Warranties: Shingles have their own warranties varies as per their building material, such as the asphalt and fiberglass shingles have the warranties as per their weight. The warranty of the shingles also depend on their weight and price like the minimal expensive and lighter weighted shingles normally comes with a 15 year of warranty but the heavier yet more costly one have the warranty for up to 25 years.

Building tip: It is mandatory to finish the building of the chimney before shingling the area around it as it will help to place the sheet metal flashing around the areas as a waterproof and reduce the damage to the shingles. Before working on the roofing areas, consult with the roofing contractor as they will be responsible for any kind of fault or damage.

Dormers: A house needs various kinds of windows, skylights, port holes, attic and similar kind of things to nourish the beauty of the house. But it is true that they bear costly charges and a high pitched roof is needed to cover them, so it is important to talk with the roofing contractors about the estimated cost of those.

A Roofing Cost Estimator

Recommend professionals: It is a very tough job indeed need risky, the work needs right planning, materials, right knowledge of costing etc, so it is better to hire a professional and consult with him for better result.
Source: Www.Byoh.Com

Published By
Rajib Dey

Tuesday, December 5, 2017

AmQuake – A powerful software for masonry building analysis

Cervenka Consulting Ltd has developed AmQuake, the useful software for earthquake engineering.

With the use of this program, the engineers will be able to create the design of safe masonry buildings in the seismic regions of Europe. This formation was supported with the introduction of Eurocode 6 and 8 in Europe. These standards become compulsory in the European Union that commences from March 2010, and they employ strong rules for masonry buildings in seismic regions. By applying pushover analysis and the corresponding frame method to examine the seismic safety of masonry buildings in a graphical user-friendly environment.

Demo version is automatically incorporated in the program. The unregistered / unpaid version of the program automatically functions in the demo mode.

The demo mode is restricted to 10 frame elements. This limitation does not include the examples provided in the installation.

The software contains the following features :-

  • Brick choice - Choose your masonry unit out of the catalogue of Wienerberger products
  • CAD building floor plan is directly imported through DXF
  • Seismic assessment is done with pushover analysis
  • It adheres to Eurocode 2, 6, and 8
  • It is compatible with 11 European versions and translated into 14 languages
  • To download the software, click on the following link Www.Cesdb.Com

AmQuake – A powerful software for masonry building analysis

Published By
Rajib Dey

Monday, December 4, 2017

Some useful tips to work out the size of the steps & the angle of the staircase

At the time of computing weight-bearing capacity, the components of the staircase are classified on the basis of cantilever or supported, each containing its individual formula for the computation.

Due to the impact of dynamic forces on the staircase, the load-bearing elements should be strongly inflexible: they should not bend surpassing 1/400 of the distance among the supporters.

The forces on a staircase originate partially from the weight of its parts (steps or platforms) and partially from temporary loads – which should be kept under 300 kg/sq.m; these forces should have been integrated. When anybody goes upward, exhausted energy becomes double as compared to proceed horizontally. It is found that a staircase is well-situated and secured if the sum of twice the risers’ height and the width of the steps are similar to an average person’s footstep. Since this average footstep is 600-640 mm, the formula for step and riser should be applied as 2a + b = 600..640 mm.

There is also another formula : a + b = 450 ± 20 mm, where a denotes the height of the step riser and b denotes the depth of the step.

Adequate depth should be maintained for the step to fit the entire foot i.e. not under 200 mm but not over 320 mm. Optimal measurements should be 150 mm for the risers and 300 mm for the steps.

A depth surpassing 320 mm will create problems to go up or down the stairs, whereas a depth under 200 mm will create problem to go down. The narrow end of turning steps should not remain under 100 mm, and the step projections (beyond the risers) should not surpass 50 mm.

If there are no other alternatives, this projection is applied to raise a step’s depth.

The most suitable angle of incline for a staircase varies from 23 to 37 degrees. Less room is required for a steeper staircase whereas more room is required for the staircase with less steep. If the angle remains under 23 degrees, then the staircase will be substituted with a ramp; if the angle is over 45 degrees, then the staircase starts to look like a ladder. The most favorable angle for a spiral staircase remains between 25-35 degrees. The main issue with a staircase steeper than 40 degrees is descending, and if it is over 45 degrees, one should descend backwards.

The number of steps is based on the distance from floor to floor and on the angle of the staircase. If the position of the staircase on the plan and the height of the room is known, it becomes easier to count the number of steps with graph paper. Then, the width of the steps is computed with the safety formulas.

If the staircase is designed with graph paper, it is essential to draw it to scale on the basis of the height of the room.

To get more details, click on the following link

Some useful tips to work out the size of the steps & the angle of the staircase

Published By
Rajib Dey

Saturday, December 2, 2017

Civil Engineering GATE 2018 – An exclusive e-book for civil engineering students

Prasant Dixit has written an exclusive construction book alias Civil Engineering GATE 2018. The book is available in paperback version.

The current GATE tutor for GATE Civil Engineering is segregated into three main sections which are known as General Aptitude, Engineering Mathematics and Civil Engineering.

These sections are again segmented into various chapters. The General Aptitude section comprises of Verbal Ability, Critical Reasoning and Numerical Ability. The Engineering Mathematics section is segregated into Differential Equations, Complex Variables, Probability and Statistics, Numerical Methods and Transform Theory. The Civil Engineering section is again segregated with twelve chapters alias Mechanics, Structure Analysis, Concrete Structure, Steel Structure, Geotechnical Engineering, Fluid Mechanics, Hydraulics, Engineering Hydrology, Water Resource Engineering, Environmental Engineering, Transportation Engineering and Surveying.
All the chapters are supported with nit wise and topic wise collection of theory and question answers. The entire coverage of the syllabi in the book remains equivalent to the format of the exam along with appropriate study material and different types of questions having their complete solutions. All the chapters in the book include adequate number of solved problems which are prepared based on the lines of questions appeared in previous years' GATE Civil Engineering.
Under the Unit Exercise sections, there are unresolved practice questions. All the questions in the exercises are prepared on the basis of the GATE pattern that means. 1 mark questions, 2 marks questions and common data and linked answer questions. The book includes Unit wise Numerical Answer Type Questions and newly inserted topics in questions. There are also last six years' (2012-2017) solved papers of original online GATE Civil Engineering to facilitate the candidates to have clear conceptions on the trends of questions solicited in GATE Examination.
This book also involves focused study material for General Aptitude and Engineering Mathematics. In the last chapters, the newly inserted topics in GATE syllabus are also given together with five Mock Tests to allow candidates to prepare themselves and self analyze their level of preparation for the forthcoming GATE Civil Engineering 2017. The book contains a free CD with Online Mock Tests for GATE Civil Engineering.

Published By
Rajib Dey

Friday, December 1, 2017

How to calculate mason, labor for brick masonry construction with help of thumb rule

In this construction video tutorial, you will learn how to compute the mason as well as labor toward a 1st class brick masonry construction with the help of thumb rule.

A thumb rule refers to a principle having extensive application that is not projected to be exactly perfect or authentic for each situation. This method can be easily applied for making approx calculation or recollecting some value, or for making some determination.

It should be noted that the quantity of required labor will be gradually increased from ground floor to first floor to second floor etc.
Thumb rule is a constant value that is taken from the earlier construction work i.e. how much volume is covered by the labors employed in earlier projects. All the volumes are summed up to find out the average volume.
In ground floor, first floor and second floor, the volume of total area is taken as 150 m3
Ground floor :-
Mason = Volume x thumb rule (for mason) = 150 x 0.71 = 107 numbers
Now, suppose the charge for one mason = 1100 rupees
So, the cost for mason will be 107 x 1100 = 117, 700 rupees
Labor = 150 x 1.18 (thumb rule for labor) = 177 numbers
Suppose, one labor charge 800 rupees
Therefore, cost of labor = 177 x 800 = 141,600 rupees
Similar process should be followed for 1st floor and 2nd floor. Here, the value of thumb rule will be increased as the steps are increase.
To learn the calculation for 1st and 2nd floor, watch the following construction video tutorial.

How to calculate mason, labor for brick masonry construction with help of thumb rule

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Published By
Rajib Dey