DND Construction Civil Knowledge

Important points to remember for Civil Site Engineer

Every engineer must know to avoid error on-site while working as Explained below

1. Clear Cover to the main reinforcement            Footing : 50 mm            Raft Foundation Top : 50 mm, Bottom/Sides: 75 mm            Beam : 25 mm            Slab : 20 mm            Column : 40 mm            Staircase:15 mm2. The standard weight of 1m steel bars
Formula: the weight of bar per meter length = d²/162 kg/m , d-diameter of bar in mm      8 mm 0.39 kg/m      10mm – 0.62 Kg/m      12mm – 0.88 Kg/m      16mm- 1.58 Kg/m      20mm – 2.47 Kg/m      25mm – 3.85 kg/m      32mm – 6.32Kg/m

3. One Way Slab      The ratio of longer span (l) to shorter span (b) is equal or greater than 2      The main reinforcement is provided in shorter span & distri. Reinf. in the longer span.

4. Two Way SlabRatio of longer span (l) to shorter span (b) is less than 2load will be carried in both directions. So, the main reinforcement is provided in both direction for two-way slabs.

5. Main bars in reinforcementMain bars in the slabs shall not be less than 8 mm (HYSD) or 10 mm (Plain bars)

6. Distribution bars      Distribution bars are not less than 8 mm and not more than 1/8 of the slab thickness.

7. Minimum thickness of slab is 125 mm

8. Compressive strength of Bricks is 3.5 N / mm2 and                Water absorption should not be more than 15 %

9. The freefall of concrete is allowed a maximum to 1.50m.

10.  Excavation work for basement above 3m should be stepped form

11.  Electrical conducting shall not run through the column

12.  Dimension tolerance for cubes + or – 2 mm

13.  The pH value of the water should not be less than 6.

14.  In soil filling as per IS code for every 100 sqm, 3 samples for core cutting tests should be taken.

15.   Lapping is not allowed for the bars having diameters more than 36 mm.

16.  Longitudinal reinforcement not less than 0.8% and more than 6% of gross c/s.

17.  Minimum bars for the square column is 4 no’s and 6 no’s for the circular column.

18.  Samples from fresh concrete shall be taken and at least a set of 6 cubes of 150mm shall be prepared and cured. 3 Cubes each at 7 days and 28 days shall be tested for compressive strength. The test results should be submitted to the engineer for approval. If results are unsatisfactory necessary action/rectification/remedial measures have to be exercised.

19.  Slum of concrete as per IS codeLightly reinforce structure is 25mm-75mmHeavily reinforce structure is 75mm-100mm

20.  Curing time of RCC Members for different types of cementSuper Sulphate cement                      :  7 daysOrdinary Portland cement OPC         : 10 daysMinerals & Admixture added cement: 14 days

Watch full video on this link https://www.youtube.com/watch?v=8kC9KPEq9Wk

DND Construction

The construction process of RCC Column of building and checklist of RCC Column

The construction process of RCC Column of building and checklist of RCC Column and the checklist of column concreting work follow on site

Watch the full video on Youtube

https://www.youtube.com/watch?v=rQiXSzsitr0

The construction process of RCC Column of building and checklist of RCC Column as explain in this 4 steps

What is Column?
-Verticle member of the building
-Transfer the load from the slab, Beam to footing
-The building stands on columns

The basic Construction process of column activity is divided into 4 steps as follows

Step I Layout work of column
-In this, with the help of drawings, we do grid linework on-site as x-axis and y-axis and find the location of the columns with surveying instrument like auto level, theodolite, etc
-After determining the position of columns, we do marking of columns on-field practically

Step II Column Reinforcement work
-After marking the column locations, we then start to place verticle bars of steel as per the structural consultant column schedule drawing.
– we place vertical bars, stirrups, and covering work as per column schedule drg.

Step III Column formwork
-Column formwork is a temporary arrangement for the pouring of concrete.
-we do first starter work then we start the shuttering process.
-we are the support of the column shuttering by props and turnbuckle as per site condition.

Step IV Pouring concrete into the column.
-After shuttering checking and taking permission from the client we start concreting work of column
-For concreting, walking arrangements should be done with laborers.
-Pouring is done in 2 ways
1. By manually
– the small quantity of concrete volume we normally mix on-site by a mixer and pouring done by wheelbarrow or Ghamela tub.
 2.By pumps or concrete pouring machines
-the large quantity of concrete volume, we use ready mix concrete (RMC) and transportation done by pumps or machines

Column checklist for the construction process of column

-We follow the checklist process on-site as describe the DND Construction format
-Date, location of the column, the grade of Concrete, the grade of steel, drawing details, etc should be filled on a checklist during checking of the column.
-After filling all observations we take the client sign-on checklist and taking permission.
– the checklist is a document that can be used for future use and for the record.

Watch video on below link

https://www.youtube.com/watch?v=rQiXSzsitr0

The construction process of Building/Housewatch full video on below linkhttps://www.youtube.com/watch?v=Q0m0EQoDmkkThe Construction Process of building or House in Step by Step of each activity is as follows in 9 steps explain
Step 1 Study of the drawings
-we study all the Architect, RCC drawings finishing drawings of the building before starting the building construction work, after study of drawings we next do site preparation workStep 2 Site Preparation Work
-As per the drawing, plot area is marked on the field Construction process of building/House
-The Building construction site needs to do cleaning work before the excavation work is executed.
-The removal of debris, cutting of trees, other unwanted materials removed from the site.
-After Cleaning nee to do leveling work of the groundStep 3 Excavation Work
-As per building foundation drawings, starts excavation of the ground.
-Excavation work is done with the help of excavating machines such as JCB, Poclain,etc DND Construction and manually with the help of labors by Hoe or shovels,etc.
-Excavation work done till hard strata is visible.Step-4 PCC (Plain Cement Concrete) work
-We remove all excavated materials from the site and cleaning is done properly.
-Concrete low grades like M10, M12.5, or M15 is used for PCC work.Step 5 Foundation Work
-A foundation is a lowermost part of a building structure that transfers all building load to the earth.
Foundation work of activity includes
-Reinforcement work of footings
-Shuttering work of footing
-Concrete Pouring work of footings
As per the above steps we complete all footing work as per RCC drawingsStep-6 Backfilling work
-Backfilling is the process of filling the excavated Plinth or trenches after the construction of footing.
-Plinth filling is done to fill the area within the Plinth.
-Soil well compacted before starting the plinth workStep 7 Plinth beam and slab work
-Plinth beam and slab make the structured composite
-Plinth beam is a reinforced concrete beam constructed between the wall and its foundation.
-The plinth beam is provided to prevent the extension or propagation of cracks from the foundation into the wall above when the foundation suffers from the settlement.
-Plinth beams distribute the load of the wall over the foundation evenly.Step 8 Column Construction Work
-Column is a vertical structural member of building that carry loads mainly in compression.
 construction activity of column as follows
-Reinforcement work of column
-Shuttering work of column
-Concrete Pouring work of columnStep 9 Slab Construction work
-A slab is a structural element, made of concrete, that is used to create flat horizontal surfaces such as floors, roof decks, and ceilings.
-Reinforcement work of slab
-Shuttering work of slab
-Concrete Pouring work of slabThis is how Residential building Construction activities of step by step going on-site. this step varies as per site conditions, these are the basic sequence of activities
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