I am opening the thread to showcase different method of duplexes construction in Nigeria.

So many of our job underway in different part of the country will be showcased here.

First stop: Benin, in this old city of former bendel state capital and now capital city of Edo state, we will be supervising the construction of a semi detached five bedroom flat with a two unit two bedroom flat

Front seat taken!

Setting out: which involves transferring of the information on the architectural, structural and services drawings on to the ground to help marked out the foundation excavation.

Materials used include the following :
Pegs
Profile ( 2 x 2)
Builders square
Hammer
Line or builder rope
Meter tape
Nails etc.

Following. I would like you to showcase ways to reduce excess load on One-story duplexes. I am of the opinion that Nigerian builders strain the foundation by packing too much weight on the upper floor.

Do we really need all that Iron rods for a residential duplex. The Pillars and columns are meant to hold the upper floor. Throw some more light on this.

abdulwastecx:
I am opening the thread to showcase different method of duplexes construction in Nigeria.

So many of our job underway in different part of the country will be showcased here.

following

koning:
Following. I would like you to showcase ways to reduce excess load on One-story duplexes. I am of the opinion that Nigerian builders strain the foundation by packing too much weight on the upper floor.

Do we really need all that Iron rods for a residential duplex. The Pillars and columns are meant to hold the upper floor. Throw some more light on this.

I am on the same page with you on how to reduce weight of suspended slab but the misconception here is that the majority weight of slab is that of the conconcrete. In most cases, reinforcement bar contribute less than 10% to the weight of any structural members be it slab, column, beams or footing.

Another major contributor of load to suspended floor is partition walls. 225mm partition walls contribute as much as 3.6kN/m 2 when built on slab without bottom beam.

Best way to reduce load on suspended floor is reduce quantity of concrete and portion loads by using thinner section for upper wall, light weight materials for upper walls etc

Stage 2: excavation work
Before we go into excavation, I will like to explain our foundation type for this building. We are going to be using pad footings to carry all the structural columns what strip footings carrying the foundation wall and ground floor walls.

The size of the footings are as follows
Pad type one = 1200mm x 1200mm
Pad type two = 1500 x 1500mm
Pad type three = 1800 x 1200mm
Thickness of pad = 350mm

Pad reinforcement : using Y12 mm bar spaced @200mm center to center

Preparation of foundation basket and foundation column/short pillars.
We have 38 columns and 35basket
32 of these basket are isolated pad base while 3 are combined pad base.

The foundation column/pillar is made up of Y16mm and 8mm ring spaced @200mm c/c

Foundation footings concreting work:
The foundation foot was casted with the following aggregates :
19.5mm coarse aggregates (ganite/gravel)
River sharp sand and ordinary Portland cement.

Mix ratio was 1:2:4 by weight

Foundation block work
Foundation block is 9 inch or 225mm thick (450 x 225 x 225).

Height of block work up to dpc level = five courses of block work.
Mix ratio of mortar 1:6

More foundation block work updates

Foundation pillars formwork and casting

More block work updates

More foundation block updates

Introducing a plint beam of 225mm x 225mm beam, reinforced with 2Y12 up and 2 Y12 bottom.

More updates from plinth beam construction

Plinth beam is a beam that is used to connect all the foundation column at a level a little bit above ground level or immediately above grade.

It serves as a tie and also help to provide end restrain to the foundation column for a very high dpc above ground level.

It help to provide top restrain to reduce slenderness ratio of columns or pillars.

Also help to strengthen foundation block above ground to help it serve as a retaining wall when sand filled

Sand filling and compaction of foundation to dpc level

Ground floor plumbing layout for all waste pipe.

abdulwastecx:
Stage 2: excavation work
Before we go into excavation, I will like to explain our foundation type for this building. We are going to be using pad footings to carry all the structural columns what strip footings carrying the foundation wall and ground floor walls.

The size of the footings are as follows
Pad type one = 1200mm x 1200mm
Pad type two = 1500 x 1500mm
Pad type three = 1800 x 1200mm
Thickness of pad = 350mm

Pad reinforcement : using Y12 mm bar spaced @200mm center to center

Can you explain why you chose this type of foundation?

msogunro:


Can you explain why you chose this type of foundation?

That was the structural design specifications. It was in the structural drawing. We also cost checked all the design before starting the project.

For educational reason: width of foundation is mechanically gotten from the relationship between all the axial load acting on the building and the bearing capacity of the soil beneath the footings.

Assuming axial load acting on the footing through the column is N
Allowable soil bearing pressure at certain depth where the footing is to be located is P
Area of footings A
Width of footing B

Mathematically A = 1.1N/P
Where N is only the serviceability load acting the footing.

For square footing, B = square root(A) plus some allowance

The depth of the footings is assumed at first and check for shear later during shear calculation.

Diameter of bar, bar spacing are chosen based on the result of bending calculations

More plumbing work

Note: provisions were made for plumbing work without breaking structural wall for them. It is a very good way to do conduit plumbing work

Formwork to the dpc, placement of DPM and casting of dpc

Preparation of our starter bar for stair case. This building has three stairs with the following information.
Width of stair = 900mm

More updates

Ground floor block work

More updates

following....
abdulwastecx I'm signing in fully. I hope say form never finish...

emmadejust:

following....

abdulwastecx I'm signing in fully.
I hope say form never finish...

For my oga like you... Form go always dey ground. Welcome

Silent Lurker.

Hajji M.