akobo construction field report-draft.doc pdf
Post on 05-Apr-2018
223 Views
Preview:
TRANSCRIPT
-
7/31/2019 Akobo Construction Field Report-draft.doc PDF
1/19
2012
Akobo field construction Report Page 1
ProjectCompound Improvement
For
Akobo Field Office
Undertaken by
Contractor: GASCO Limited
Compiled by: Ladu George Lambu
Construction Supervisor, SCI AKOBO.
Checked by: Stephane K,
Construction Consultant, SCI JUBA
Date: 6th
May 2012
-
7/31/2019 Akobo Construction Field Report-draft.doc PDF
2/19
2012
Akobo field construction Report Page 2
SCOPE OF WORKS
The Contractor was awarded the contract, number PB/135/11/UN on the first dayof February2012 to construct an office block, two separate latrines each with four
stances and the Chain link fence, to be completed within 90 calendar days upon
the date of the contract signature.
IMPLEMENTATION
From 8th
march 2012 the contractor arrived and took over the site. From the 9th
Between 10
of March the SCI logistics manager was requested about the local material
sources, whereby he had to assist in the local mobilization of sand and aggregatebut he was busy and could not make it for that day.
thand 16
th
From 17
of March (a duration of 6 days), there was no major activity
going on for the reason being that land Boundaries for SCI compound had not yet
been decided between the SCI and the local authority and the local materials had
not yet been fully mobilized.
th
Foundation works had to go on for three consecutive days till 20
of March, the foundation works started by setting out and excavation as
per the drawings within the defined boundaries as it had been agreed by the local
authorities and SCI management.
th
The foundation works proceeded immediately after the bulk materials had been
secured and delivered on site.
of March when
it was stopped after a decision taken by the contractor through the foreman to
switch to the mobilization of materials which had to do with the collection of sand
from River Meer area and local aggregates from the same area.
From the foreman, Tony, we were able to get information that all the rest of
materials apart from sand and local aggregates, were to come from Juba
-
7/31/2019 Akobo Construction Field Report-draft.doc PDF
3/19
2012
Akobo field construction Report Page 3
including; marrum / gravel , harder aggregates and the rest of the material to
complete the works . This was to take only 3 days for all the materials to be
delivered.
We found out that all the walling was done by use of cement/sand blocks made in
situ on site. Some of the blocks indicated that they were very weak and
crumbling. Well, the foreman had to explain as to why as such was happening for
the first batch of blocks before they were even used and he said that it was the
first trial test that was done by a 1:4 ratio (cement bag: wheelbarrow of sand)
instead of 1:3 mix ratio that is commonly used.
On the same note, the wall thickness done on site for the foundation walls (plinth
walls) for all the construction is 150mm compared to that in the drawing which is
specified as 400mm for the Office block as per the drawing and 200mm thickness
for the toilet walls.
The foreman had defended himself that it was all about the mould that was
delivered on site that gave him no option. The mould could make block sizes of
150x200x400mm compared to the expected 200x200x400mm solid blocks.
Basically the walls were built on edge instead of building on bed to achieve the
200mm desired thickness.
There was enough evidence that curing was not done effectively otherwise it
could have been the ratio that was poor on top of the clay impurities in the sand
that led to the poor quality of the first lot of the blocks that were made.
THE PROJECT WAS DELAYED
We looked at the time frame and got worried about the time left compared to the
works left to be done. The contract was signed on the 1st
of February 2012 and
the project duration is for only 90 days. This means that the contractor has only
the month of May to cover everything to turn key and handover.
-
7/31/2019 Akobo Construction Field Report-draft.doc PDF
4/19
2012
Akobo field construction Report Page 4
When we tried to track backwards, it was found out that work started onthe 8
th
The project commencement was earmarked when a team of 5 Masons(skilled laborers) and 6(unskilled laborers) Helpers and their foreman
arrived in Akobo.
of May 2012, which was one month and a week late ever since the
project was signed and we could not get any reason as to why this
happened that way.
On the other hand, the foreman explained that they had to wait foranother 6 days before the new SCI boundaries had to be negotiated
between the SCI admin and the local authorities.
That, rain had interrupted twice ever since the project started. This was inthe mid march when rain started at around 11:00 am and work came to a
standstill until the next day. The other occasion was in the first week of
April when it started raining at around 2:30pm and work couldnt proceed
until the next day.
The last delay was from the time when cement got finished and the workshad to come to a stand still waiting for the materials from Kampala. Our
estimation was for about a week when these materials had to reach Juba
and three days for the materials to reach Akobo from Juba. Fortunately,
the consignment was sent on Wednesday 1st
of May from juba and it
reached on the 4th
day of May 2012 to Akobo, the day after our arrival in
Akobo.
-
7/31/2019 Akobo Construction Field Report-draft.doc PDF
5/19
2012
Akobo field construction Report Page 5
TECHNICAL FINDINGS
HOW IT WAS DONE ON SITE FROM THE CONTRACT DOCUMENT
OFFICE BLOCK:
The plinth wall thickness is150mm,
The plinth wall thickness is400mm,
The Stud columns are 150mmx200mm,
The Stud columns are 400mmx400mm,
The RCC ground beam is150mmx200mm,
The RCC ground beam is300mmx300mm,
The marrum / Gravel layerthickness is 65mm,
The murrum / Gravel layerthicknesss is not indicated.
The DPM Ga 1000 PVC membranewas not provided,
The DPM Ga 1000 PVCmembrane was not
documented,
The BRC reinforcement Bars to theslab are R8 tied @ 370mm spacing,
The BRC reinforcement Bars areindicated as Y10 to be tied @
300mm spacing, The stirrups used are R6@300mm
spacing
The stirrups specified areR8@200mm spacing.
FENCE
The spacing of the angle line pits is3000mm c/c @ the depth of
600mm with diameter of 250mmon average.
121 pieces of 50x50x6mm AngleDelivered on site
The spacing of the angle line pitswas not indicated and the depth
of 400mm/ 500mm with a topcross section area of 300X300mm
was specified in the BOQ.
Required is 174 pieces of50x50x6mm Angle as per the
-
7/31/2019 Akobo Construction Field Report-draft.doc PDF
6/19
2012
Akobo field construction Report Page 6
BOQ to cater for struts and
Strainers for the fence
VIP LATRINE, 2No @ 4-stance
The deepest end of the pitexcavated is 4000mm from the
ground level.
The depth of the pit could not beread from the document i.e the
section detailed drawing for the
pit was missing from the
document.
The top section of the built pit is1500x4700mm internally and
1600mm depth from the ground
level. And the bottom section of
just mere excavated pit separated
by a 65mm thick slab is
790mmx4000mm and 2600mm
deep.
Ditto but the drawing planspecifies 900x4000mm top areaof the pit which differs from the
1300x2100x5000mm as per the
BOQ ,
The total excavated volume wascomputed to be 20m
The total volume to beexcavated was 28m
3
3per 4stance
pit as per the BOQ
The slab thickness to one of thetoilets near the office block was
made to be 65mm thick with Y12
rebar @ 300mm spacing and
covered by the welded wire mesh
on top.
The slab was specified to be100mm thickness for all the
toilets as per the BOQ.
-
7/31/2019 Akobo Construction Field Report-draft.doc PDF
7/19
2012
Akobo field construction Report Page 7
MATERIALS DELIVERED TO THE SITE
The last batch of the materials for the completion of the work arrived yesterday4
thMay 5, 2012 at around 3:00 pm, it took 3 days to reach AKOBO from Juba.
These included:-
Item Details Quantity Unit Remarks
1 Portland Cement, Rhino
Brand
250 Bags Non was damaged
2 Y12, Reinforcement bars 38 No
3 Iron sheets, Ga 28 pre-
painted maroon in color
145 Pcs
4 Welded Wire
mesh,120x240mm
3 Pcs
5 Wooded Door frames 8 Pcs
6 Softboards,122x244cm,10mm
thick
65 Pcs
7 Sadolin paints, Emulsion,
under coat
Jkans
8 Sadolin paints, Emulsion,
Final coat , cream
Jkans
9 Sadolin paints, Gloss
paint
Jkans
10 Sadolin paints weather 4 tins of Tin
-
7/31/2019 Akobo Construction Field Report-draft.doc PDF
8/19
2012
Akobo field construction Report Page 8
guard 20Ltr @
11 Metallic doors for VIPLatrines, 80cmx210cm
8 pcs
12 Flash Timber doors 4 pcs
13 Barbed wires,25kg Roll 3 Rolls
14 Main Gate
Metallic,4000x2100
1 No The small pedestrian gate
was not provided
15 Binding wire 10 Kg
16 Putty for glasses 2 Tins
17 50x50x6mm Angle bars 121 Pcs
17 Wood preservative 3 Jkans
18 Burnt clay Vent
bricks,220x112x75mm,Z
design
20 Pcs
19 Hand crashed Aggregate 10 Ton
20 Chain link 20 Rolls
21 Tension wire for the chain
link
3 Rolls
22 Ridge caps 25 Pcs
23 Valleys @ 2m long 5 pcs
24 2x6 common timbers 45 pcs
-
7/31/2019 Akobo Construction Field Report-draft.doc PDF
9/19
2012
Akobo field construction Report Page 9
25 2x4 common timbers 315 pcs
26 2x3 common timbers 90 pcs
27 1x9 Fascia boards 32 pcs One was damaged during
delivery
28 Metallic doors for the
latrine 750x2100mm sizes
8 pcs
29 1200x2200mm Double
door
1 pcs
30 Casement Windows
,1mx1.2m
22 No 9 windows were damaged
and need welding ,panel
beating repairs & painting
31 Assorted Wire Nails
6 25 Kgs
5 6 Kgs
4 7 Kgs
3 35 Kgs
2 5 Kgs
Roofing Nails 20 Kgs
Rubber washers Are missing, not brought
Hoop Iron 5 Rolls
DPC 5 Rolls
-
7/31/2019 Akobo Construction Field Report-draft.doc PDF
10/19
2012
Akobo field construction Report Page 10
Recommendations
Latrines:
We would recommend that the intended detailed section as part of the drawing
to be delivered for comparison or, to give us the precedence and guidelines in
controlling the already existing part. This would help us to make quick adjustment
as soon as possible. For example its quick not clear about the specific guide
concerning the pit depth and its top area. For the BOQ, it specifies1300x2100x5000mm and the drawing indicates 900x4000mm. The contractor
decided to excavate 4000mm as the pit depth from the ground level but in steps
as indicated in the table of observations above. Please find the attached sketches
of the as built sections of the toilets.
Office Block:
The recommended BRC from the drawing was y10 bars @300mm spacing c/c
fixed with binding wire contrary to what was done by the contractor where R8
bars spaced @370mm c/c was used. This is the point dragging us to another level
until we get a go ahead from the construction manager; the condition has already
been raised to his attention.
We had taken a quick decision of improvising by just reducing the spacing through
addition of more bars but the foreman had to confirm from his boss first.
And concerning the stirrups for the beams and columns, we were suggesting that
the use of R6 bars instead of the specified R8 would call for a reduction in their
spacing from the original 300mm to 150-200mm if only approved by the designer.
-
7/31/2019 Akobo Construction Field Report-draft.doc PDF
11/19
2012
Akobo field construction Report Page 11
On the other hand, for the wall, we had suggested to use the hoop iron
reinforcement @ every two courses to counter cracking.
DPM
The DPM, Damp proof Membrane was ignored by the contractor simply because
it was not part of the drawing and in the BOQ. We thought that the DPM is the
protective layer of the slab and the reinforcement against the raising moisture.
On the same note, it was not procured. If we could ask for precedence from the
designer, then we are safe.
FENCE
We would recommend that the fence needs more reinforcement in any way to
provide sufficient support to it laterally. This could be archived by improvising
more angle line bars for struts and the required strainers and terminal posts or
additional Timber poles @ not < 10m with deeper excavation depth.
WATER
More water will be needed for future use especially for concrete works andcuring. Curing is mandatory and requires relatively more water. The only nearest
water source point for clean water is the compound bore hole and it this calls for
a maximum storage and water reservation from the contractor.
-
7/31/2019 Akobo Construction Field Report-draft.doc PDF
12/19
2012
Akobo field construction Report Page 12
-
7/31/2019 Akobo Construction Field Report-draft.doc PDF
13/19
2012
Akobo field construction Report Page 13
akobo 1: This the Arial view of one of the toilets.
-
7/31/2019 Akobo Construction Field Report-draft.doc PDF
14/19
2012
Akobo field construction Report Page 14
akobo 2: This side show how the soils are terrible, even up to the 2m depth, foundation cannot be guaranteed.
So what the contractor did was to excavate below to a depth of 1500mm for the wall seated on a slab as seen in
the photo, below this is a simple slab of 65mm made of 1:2:4 plain concrete according to the F/man.
-
7/31/2019 Akobo Construction Field Report-draft.doc PDF
15/19
2012
Akobo field construction Report Page 15
akobo 3: The slab thickness is 65mm, reinforced as per the F/man. We thought maybe the strength is currently
based on the formwork which is still below it.
-
7/31/2019 Akobo Construction Field Report-draft.doc PDF
16/19
2012
Akobo field construction Report Page 16
akobo 4: This is the layout of the foundation and the interest was in the spacing of the Rebars, the raise of the
plinth wall from the ground floor level.
-
7/31/2019 Akobo Construction Field Report-draft.doc PDF
17/19
2012
Akobo field construction Report Page 17
akobo 5: These are some of the materials which were brought in the last consignment, of course some were
damaged during transit especially the paint, windows and angle bars,
-
7/31/2019 Akobo Construction Field Report-draft.doc PDF
18/19
2012
Akobo field construction Report Page 18
akobo 6: (Left) are the hand crashed aggregate fetched all the way from Juba. (Right) are the stones collected
from the river banks.
-
7/31/2019 Akobo Construction Field Report-draft.doc PDF
19/19
2012
Akobo field construction Report Page 19
akobo 7: This is one of the blocks that were molded on site. It shows that sand is impure with clay particles and
rubbish. The quality could partially be improved by sieving sand before use.
top related