HOW TO CALCULATE THE CEMENT & AGGREGATE QTY FOR CONCRETE

take the ratio 1:1.5:3
cement =1
sand =1.5
metal =3
So what is the ratio we want to mixing 1+1.5+3=5.5
Volum of wet cement concret is 1.54 to 1.57
unit weight of cement bag is 1440 kg/cum
one bag of cement = 50/1440 = 0.034722 cum

SOLUTION : CEMENT = 1.54/5.5 =0.28
=0.28/0.0347 = 8.069 ( 8 bags)
one bag of cement =50 kg X 8.069 = 403.45 kgs.

SAND solution =0.28 X 1.5 = 0.42 Cum
1.5 is the mixing proportion
METAL SOLUTION = 0.28 x 3 = 0.84 cUM.
3 is the mixing proportion
1 Cum cement concrete is 1:1.5:3 ratio

cement = 403.45 kgs.
sand = 0.42 Cum.
metal = 0.84 Cum.

HOW TO CALCULATE CEMENT & SAND QTY FOR PLASTERING

10 feet= 3.05m

area of plaster = 3.05 x 3.05 = 9.3 m2
(convert thickness of plaster into m divide by 1000)
volume of plaster = 9.3 x (10/1000) = 0.09 m3
quantity of cement = 0.09/1+5 =0.09/6 = 0.02 m3
as cement comes in bags of 50 kg therefore volume of one
bag cement = o.0347 m3 (exact)
(or it may be taken 0.034 or 0.035 m3)

no. of cement bags = 0.02/0.0347 = 0.58 bags (almost 1 bag
of cement required for plaster )

quantity of sand = 0.02 x 5 = 0.10 m3

this is exact calculation
you can add 30% extra for wastage etc.

HOW TO CALCULATE CEMENT, SAND & BRICKS FOR BRICK MASONRY

Consider Brick Masonry for 1 cum with 1:5 ratio mix

1). Brick calculation
take brick size =200mmx100mmx100mm
convert in meter =0.2mx.1mx.1m
total volume of brick= .2x.1x.1=0.002 cum

calculate the numbers of brick for 1cum = 1cum/0.002cum= 500 numbers of bricks.

2). cement calculation
the ratio of cement mortar =1:5
sum =1+5=6
total dry mortar requried for 1 cum brick masonary=.30cum
so,
cement = (.30x1)/6= 0.05 cum
convert in KG=.05x1440=72KG
convert in cement bag= 72/50=1.44bag.

sand calculation
sand =(.30x5)/6=.25cum
convert in kg =.25x1440=360Kg.
to convert in cum
sand = .3*quantity of sand(5)/total of ratio
= .255 for one cum 

My green building project during my college days (2010)

ELEVATIONS DESIGNS By Mr. Siva Subbiah

Fig 1 : Kerala architecture type individual villa

Fig 2 : Indian latest trend individual villa

Fig 3: Individual villa suitable for panchayat approval

Fig 4 : G + 2 rental type homes

Fig 5 : Individual small size villa front elevation

 

REBAR NOTES TO SITE ENGINEERS

Following are the general points to remember for civil site engineers to make the construction work easier while monitoring quality of construction related to reinforcement work,

• Lapping is allowed for the bars having diameters more than 36 mm.
• Chair rod maximum spacing is 1.00m (or) 1 no per 1m2
• For dowels rod minimum of 12mm diameter should be used.
• Chairs minimum of 12mm diameter should be used. 
• Longitudinal reinforcement not less than 0.8% and more than 6% of Cross C/S 
• Minimum bars for square column is 4 no’s and 6 no’s for circular column. 
• Main bars in the slab shall not be less than 8mm (HYSD) or 10mm (main bars) and the distributors not less than 8mm and note more than 1/8 of slab thickness.

• Minimum thickness of slab is 125mm ()

• Dimension tolerance for cubes + 2 mm

• Free fall of concrete is allowed maximum to 1.50m.

• Lap slices not be used for bar larger than 36mm.

• Water absorption of bricks should not be more than 15%

• PH value of the water should not be less than 6

• Compressive strength of bricks is 3.5 N/mm2

• In steel reinforcement binding wire required is 8 kg per MT

 

PROJECT METHODOLOGY

PROJECT METHODOLOGY

 what is project? What are its scope? What is the role & responsibility  for successful completion of a project ? Let me discuss in detail in a flow of methodology.

1. ESTIMATION (Quantity Survey) 

When a project is approved by a client for direct execution or any opening of a tender, estimation & quantity survey is the first procedure to calculate the boq, scope, spec, budget, material, margin, brand & other resources. The Estimation finalize the cost of a project. For good estimation to avoid the loss of cost after completion of a project, following methodology should be considered during estimation,

1. 5% to 10% qty should be considered extra along with actual. Example if total concrete qty is 100 cum + 10% = 110 cum should be finalized. During execution it is best to control it within actual qty.
2. 10% to 20% of rate should considered with present market material rate based on the completion of schedule. Example if the present cement bag rate is Rs. 400 + 20% = Rs. 480. Based on the past market study & experienced professionals it can be fixed.
3. Over head costs like temporary site office building cost, fuel cost, transportation cost, site engineers or project employees salary should considered which is excluding the margin value.
4. While preparing the estimation it is good to divide the estimation value stage wise for better budgeting of project.

Estimation is the base line for a project for fixing  the budget, spec, quality, stages of payment. It is best to do the estimation with a micro level stages. It is time consuming & little tedious, but it much helpful to calculate even a rate of small nail to forecast the project budgeting immediate during execution of any stages.

2. SCHEDULING

A Project without schedule is like a ship sailing without knowing its direction and destination. Scheduling of a project with start & end date of activities with its predecessors helps to plan the required resources, budget cash flow for the project, organization budgeting.

There are many scheduling software Primavera, MS Project available for advanced way of planning & scheduling the activity. But a good, systematic scheduling can be done by using MS Excel in a simple way as follows.

 

In the above image, a scheduling contains the description of works or work break down structure (WBS) , no of days for completion of an activity, start date & end date, in gantt chart view all the columns shows the calendar with month. In the graphical view of gantt chart , black color shows the planned schedule, green color shows the actual executed schedule, while vertical ash color shows the non-working days or Sunday’s. 

[ For format of scheduling to receive the soft copy of it, please feel free to email to subbiahinfrastructure@gmail.com ]

For better understanding about bar chart scheduling system one more illustration given above with few more details. As it is black horizontal line shows the planned schedule, green line shows the actual schedule, red line shows the no progress, while yellow line shows the delay or advance of completion of activity. Based on our idea & creativity, schedule reporting can be done any of our style.

3. PROCUREMENT  SCHEDULE

Other than the execution schedule, procurement schedule helps to remind to purchase the required resources on time as per the activity schedule, since material plays the major role for completion of project on time.

A procurement schedule can be made as follows

 

Based on the above fig for procurement bar chart, example shown for aggregates with activity qty wise & stage wise with delivery date of material 7 days before of the activity start date. It can be altered in any manner based on the planning engineer requirement. 

3. PROJECT MONITORING & CONTROL

After completion of estimation & scheduling, next is the major part of the project management is the execution of the project. The proper monitoring & controlling while executing the project because it should done within the estimated qty & planned schedule. The Project monitoring & controlling system can be made by implementing DPR (Daily Progress Report) system. The DPR should covers the follows :

• Day progress measurement in LBD and total qty execution of day
• Consumption of materials like cement, electrical,plumbing materials.
• Manpower or Manday along with their workman ship (Example : if Brick work done, how many masons & helpers involved in the work qty of brick work done in how many hours of time.

Is it the work progress is as per the schedule, the future plans to complete the task and constraints or disturbances to complete the task as scheduled.

 

CONCLUSION

The motto of this article  is to guide fresher's and professionals in practical approach to understand site & project management.