Chöông I PHAÀN MÔÛ ÑAÀU Binh Duong Solid Waste Treatment Plant Page 3 of 5 Contents 2Chapter 1 PREAMBLE 2I Scope of the Project 2II Advantages and Disadvantages of the project 2Chapter 2 GENERAL REQUI[.]
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Contents
Chapter 1 - PREAMBLE 2
I Scope of the Project 2
II Advantages and Disadvantages of the project 2
Chapter 2 - GENERAL REQUIREMENTS 2
I Standards and codes applicable during the construction 2
II Site office 2
III Laboratory 2
IV Temporary Works 2
V Equipment to be furnished by the Contractor to the Engineer 2
VI Construction logbook 2
VII Equipment, machines and manpower from the Contractor 2
VII Equipment, machines and manpower from the Contractor
VIII Construction Organization Design
IX Supply and maintenance of materials, equipment
X Works to be done in the nighttime
XI Safety of traffic
XII Protection of underground utilities and services
XIII Safety for electric power wires and poles along the construction routes
XIV Water drainage system to be provided in the working area
XV Access roads to factories, plants and residents’ areas
XVI The additional works or variations
XVII Existing projects of the Employer XVIII Commencement Notice
XIX Health control
XX Joint meetings
XXI Construction inspection and management from the upper levels
XXII Documentation on the quality and quantities of works: XXIII Inspection Document and Report to the Engineer:
XXIV .Checking and inspection: XXV Completion drawings (as-built drawings)
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Binh Duong Solid Waste Treatment Plant
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XXVI .Remedy work for defects during Liquidated damages Period XXVII Treatment of breaches
Chapter 3 - SURVEYING WORK
Chapter 4 -CONSTRUCTION METHOD Chapter 5- CARE OF WATER Chapter 6 - EARTHWORKS – REINSTATEMENT OF ROADS
I Scope of work
II Trench excavation for pipe laying and fitting
III Soil improvement
IV Material for bedding
VI Reinstatement to the original status
VII Remedial work to the damages
Chapter7 - CONCRETE WORK - FORMWORK - REINFORCEMENT
I General requirements
II Requirements on the materials to be used for concrete
III Requirements on the execution
IV Quality Control
Chapter 8 - INSTALLATION OF PIPING, FITTING AND EQUIPMENT
I General requirement
II Receiving, storing pipes, materials and fittings
III Installation
Chapter 9 - LABOUR SAFETY, FIRE PROTECTION AND FIGHTING, ENVIRONMENTAL HYGIENE, TRAFFIC SAFETY AND FLOODING PREVENTION METHODS
A Labour safety
B Environmental hygiene
C Fire protection and fighting method
D Site security
E Plans of Environmental protection, Labour Safety, Safety in waterway and highway and flooding prevention
Chapter 10 - QUALITY CONTROL METHOD
I Introduction
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Binh Duong Solid Waste Treatment Plant
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II Bases for quality control of the project
III Detailed quality control measures
Chapter 11 - CONCLUSION
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Chapter 1 - PREAMBLE
I – Scope of the Project
The scope of work to be undertaken by the contractor consists
of the construction, manufacture, delivery, installation, testingand commissioning of a sewerage collection system andsewage treatment plant and the technical training for theoperation and maintenance of the constructed Works
The sewerage collection system consists of main trunk sewerpipelines having nominal diameters or indentified insidediameters of 400mm-1200mm, branch sewer pipelines havingdiameters of 200mm-315mm and tertiary (collection) sewerpipelines having diameters of 110mm-160mm, along withrequisite manholes, inspection chambers, diversion chambers,junction boxes and cleanout appurtenances Ten (10) pumpingstations will be required for lifting to the level of seweragegravity pipelines or pumping to the sewerage pumping mains.The sewage treatment plant shall have capacity of 17,650cubic metres per day (ADWF) for this Phase 1 works,expandable in the future to the ultimate Phase 4 capacity of70,600 cubic metres per day (ADWF) The contractor will berequired to provide plant in accordance with the drawings andspecifications, meeting design and performance criteria asspecified in the bidding documents
The Contract Scope of Works includes the following:
a) Sewerage Collection System Construction Works, which include:
Main trunk sewer pipelines (DN400-DN1200)
procurement and installation
Branch sewer pipelines (DN200-DN315) procurement and installation
Tertiary sewer pipelines (DN110-DN160) procurement and installation
Pre-cast reinforced concrete sewer manholes/ Inspection chambers (DN1000-DN1800) procurement and
installation
Pre-cast reinforced concrete sewer junction boxes
(DN300) / Diversion chamber (DN600) / Cleanouts (DN350) procurement and installation
Sewerage pumping stations installed in pre-cast
manholes (DN1800-DN2000), incl power supply and control system
Sewerage pumping stations installed in cast-in-situ
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concrete structures, incl power supply and control system.
Sewerage pumping mains (DN250-DN500)
Misc sewerage structures
b) Sewage Treatment Plant Construction Works, which
include:
Site preparation works including piling for structures;
Structural works for the sewage treatment plant;
Roads, drainage, final site leveling and landscaping;
Yard piping including main trunk inlet sewer,
inter-process piping and final effluent piping;
STP site buildings and structures including,
administration/laboratory building, service vehicle garage, workshop building, influent pumping station, inletworks, advanced sequencing batch reactor tanks (4), gravity thickener tanks (2) and thickened sludge pumpingstation, sludge dewatering building, UV disinfection
building, blower building, power generation building, odorcontrol system building, guardhouses and small
Advanced Sequencing Batch Reactor (ASBR) equipment;
Gravity thickeners and thickened sludge pumpingequipment;
Centrifuge sludge dewatering, sludge pumping andchemical feed equipment;
UV disinfection equipment;
Aeration blower equipment;
Emergency power generation equipment;
Odor control system equipment;
Power supply and distribution;
SCADA control system
II - Advantages and Disadvantages of the project
1 Advantages
- Working area has many small paths, therefore, the Contractorcan arrange the construction of many sections at the sametime So the Contractor can control the construction progress
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- Working in the nighttime, the Contractor can use the publiclighting system.
2 Disadvantages
- The execution of the project is carried out in the urban, so it isaffected by the traffic Traffic safety is paid attention to duringthe construction
- Working area passes through many existing public utilitiessuch as cabling, telephone cable, existing water supplypipeline, drainage, and local residents’ domestic waterpipelines along the route
- Working site is spacious, therefore it is difficult to makearrangement and protect the yard, the workshop andproperties on site
- The execution of the project will influence the lives of the localresidents and environmental hygiene during the project
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Chapter 2 - GENERAL REQUIREMENTS
I – Standards and codes applicable during the construction
1. AISC S326 Specifications for the Design, Fabrication
and Erection of Structural Steel forBuildings (referred to herein as AISCspecification)
2 ANSI A14.3 Ladders-Fixed-Safety Requirements
3 ASTM A36 Standard Specification for Structural Steel
4 ASTM A48 Standard Specification for Gray Iron
Castings
5 ASTM A53 Standard Specification for Pipe, Steel, Black
and Hot-Dipped, Zinc-Coated Welded andSeamless
6 ASTM A108 Standard Specification for Steel Bars,
Carbon, Cold-Finished, Standard Quality
7 ASTM A123 Standard Specification for Zinc (Hot-Dip
Galvanized) Coatings on Iron and SteelProducts
8 ASTM A496 Standard Specification for Steel Wire,
Deformed, for Concrete Reinforcement
9 ASTM A500 Standard Specification for Cold-Formed
Welded and Seamless Carbon SteelStructural Tubing in Rounds and Shapes
10 ASTM A525 Standard Specification for
General Requirements for Steel Sheet, Coated (Galvanized) by the Hot-Dip Process
Zinc-11 ASTM A536 Standard Specification for
Ductile Iron Castings
12 ASTM A563 Standard Specification for
Carbon and Alloy Steel Nuts
13 ASTM A582 Standard Specification for
Free-Machining Stainless and Resisting Steel Bars, Hot-Rolled or Cold-Finished
Heat-14 ASTM A666 Standard Specification for
Austenitic Stainless Steel, Sheet, Strip,Plate, and Flat Bar
15 ASTM A668 Standard Specification for
Steel Forgings, Carbon and Alloy, forGeneral Industrial use
16 ASTM A780 Standard Practice for Repair
of Damaged Hot-Dipped GalvanizedCoatings
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17 ASTM A786 Standard Specification for
Rolled Steel Floor Plate
18 ASTM B26 Standard Specification for
Aluminium-Alloy Sand Castings
19 ASTM B36 Standard Specification for
Brass Plate, Sheet, Strip, and Rolled Bar
20 ASTM B221 Standard Specification for
Aluminium and Aluminium-Alloy ExtrudedBars, Rods, Wire, Shapes, and Tubes
21 ASTM B308 Standard Specification for
Aluminium-Alloy 6061-T6 StandardStructural Shapes
22 ASTM B632 Standard Specification for
Aluminium-Alloy Rolled Tread Plate
23 ASTM F467 Standard Specification for
Non-Ferrous Nuts for General use
24 ASTM F468 Standard Specification for
Non-Ferrous Bolts, Hex Cap Screws, andStuds for General Use
25 ASTM F593 Standard Specification for
Stainless Steel Bolts, Hex Cap Screws, andStuds
Aluminium Association (AA):
1 30-86, Specifications for AluminiumStructures
2 Standard Specifications for Highway Bridges.Standards on Wires and Cables
26 BS 6004 IEC 227 PVC insulated cables
(non-armoured) for Electrical Power
27 BS 6346 PVC insulated cables for
Electrical Supply
28 BS 6749 PVC Insulation and Sheaths
29 BS 5467 IEC 502 Armoured Cables with
XLPE and HEPR thermosetting Insulation,600/1000V and 1900/3000V
30 BS 6622 IEC 502 Extruded cross-linked
polyethylene Insulation, 3800/6000V up to19000/30000V
31 BS 6500 IEC 227 Insulated Flexible Cords
32 BS 6207 IEC 245 Part 1 - Mineral
Insulated Cables
33 BS 6360 Copper Conductors for Cables
34 BS 6234 Polythene Insulation and
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Sheath for Cables.
35 BS 2897 Aluminium Strip Armour for
and Compression Joints for Cables
40 BS 6081 Termination of MICC Cables
41 BS 6121 Mechanical Cable Glands for
Elastomer and Plastic Insulated Cables
42 ISO 11801 Principle Design Standard for
Structured Cabling Systems
48 TCVN 4560-87 Water for concrete and
mortar – Technical requirements
49 TCVN 4085-1985 Bricks– Execution and
Inpection
50 TCVN 4453-1985 Concrete structrure and
erection– Execution and inspection
51 TCVN 4447-1987 Earthwork - Execution
and inspection
52 20 TCN 211 – 93 Design of roads, streets
and plaza and urbans
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asphalt concrete pavement
61 Decision Ref 166/CÑG issued by Ministry of
Transport regarding inspection of bridges and culverts Projects
62 For dutctile iron pipes with the diameters
equivalent to the standard ISO –2531.K9, test pressure of 50kg/cm2
63 Valves in accordance with ISO 9001 or
equivalent, for valves with diameters less than DN 400, gate valves to be used comply with B.S 5163
64 22TCN –33.85 Design of external water
supply pipepline made by Ministry ofConstruction
65 Technical Regulations on Labour Safety in
the construction work TCVN – 5308-91 inaccordance with Decision 156/BXD/KHKTdated 31st December 1990
II Site office
- All site activities and construction equipment and machines forthe construction of the pipeline will be arranged on thepermitted areas along the pipeline routto from the watertreatment plant to the end of the project
- The Contractor is responsible for safe preservation of facilitiesand structures such as roads, entrance gate, transmision lines,trenches, walls, box culverts, bridges, poles, supports, signs,fence, bench marks, statue and so in the areas adjacent to theproject site
- The Contractor himself will find the reasonable location to buildhis site office, storage yard and warehouse
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- The Contractor will build the site office equipped withnecessary furniture and equipment such telephone, faxmachine, computer (Pentium III), printer, Internet line.
- The site office will be arranged with two working rooms andone meeting of 15 to 20 persons with sufficient chairs, desksand tables
+ Moulds for sampling
+ Other testing equipment for slump test, moisture checking,plastic index, soil yield strength, etc
+ The other equipment is as mentioned in the designdocuments
The other equipment and tools for testing are arranged in the centerlaboratory may be rent or available from any joint venture (thedocumentations are given to the Consultant and the Employer as anevident)
IV Temporary Works
Some facilitates and equipment to be used for constructionsuch as diversion road, temporary road, and temporary facilitates,workshop, storage yards, etc are carried out before commencement
of the permanent works in the contract The Contractor can onlycarry out these works when the design documents for constructionorganization prepared by the Contractor is approved by theEngineer
V Equipment to be furnished by the Contractor to the
Engineer
The Contractor will provide the Engineer with the necessaryequipment as specified in Tender document and the Decree No.16/2005 by the Vietnamese Government and related others Allcosts for this supply are born by the Contractor as specified in theContract Conditions These costs are balanced in the tender unitprice
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VI Construction logbook
Prior to the commencement of the Works, the Contractor willprepare the construction log-book in the agreed form for the wholeWorks This book is available at all times for the Employer and theEngineer’s checking and before inspection of the work
VII Equipment, machines and manpower from the
Contractor
Construction machines and equipment and furniture for thesite office are checked in quantity and type, function and technicalaspects and approved by the Engineer in writing before thecommencement of the Works The Contractor will not mobilize theequipment, which are not certified for operation work to site
The Contractor’s manpower is provided on site as required inthe tender documents and confirmed in writing by the Engineer TheContractor will assign the staffs as mentioned in the tendersubmission If any change is made by the Contractor, the Contractwill inform it to the Engineer and the Employer in writing forapproval At least 3 days prior to the commencement of Works, theContractor will submit the Employer and the Engineer the list ofstaffs in the Project Management Unit with the necessaryinformation These staffs on site are authorized to make decisionsrelated to the site works with the Employer and the Engineer
VII Equipment, machines and manpower from the
Contractor
Construction machines and equipment and furniture for thesite office are checked in quantity and type, function and technicalaspects and approved by the Engineer in writing before thecommencement of the Works The Contractor will not mobilize theequipment, which are not certified for operation work to site
The Contractor’s manpower is provided on site as required inthe tender documents and confirmed in writing by the Engineer TheContractor will assign the staffs as mentioned in the tendersubmission If any change is made by the Contractor, the Contractwill inform it to the Engineer and the Employer in writing forapproval At least 3 days prior to the commencement of Works, theContractor will submit the Employer and the Engineer the list ofstaffs in the Project Management Unit with the necessaryinformation These staffs on site are authorized to make decisionsrelated to the site works with the Employer and the Engineer
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VIII Construction Organization Design
Before the works start, the Contractor will prepare and submitthe construction organization design to the Engineer for approval.When it is approved, the contractor will begin the works on site Thisdesign is made into 6 sets of documents (including drawings and thestatements) with the signature of the Contractor and the approval ofthe Engineer; one copy to the Employer
The Contractor will make the construction schedule for eachsection of pipeline to ensure the overall construction schedule forthe Package and the entire Project The detailed constructionschedule is based on the fixed dates in the Contract signed by theContractor and the Employer
The design for construction organization consists of thearrangement of the construction machines and equipment andmanpower for each stage of construction
The Contractor will make the construction methods to meetthe requirements on the construction schedule and quality asrequired The construction methods must comply with thespecification and procedures and approved by the Engineer
The Contractor will monitor and record the details relatedconstruction schedule, update the construction progress duringconstruction in order to complete the Works as approved If anychange happens to the agreed construction program, the Contractorwill inform the Engineer accordingly immediately
The Completion date of the Works is extended with theconsent of the Employer if any delay to this date is caused by theothers not the Contractor
IX Supply and maintenance of materials, equipment
1 Construction materials to be supplied by the Contractor
Materials before delivered to the site must be tested asspecified
Materials will be mobilized to the site when the Engineer issuesthe letter of acceptance
The sampling records, measurement sheets and testingcertificates must be signed for confirmation by the Engineer
The materials in non-compliance with the quality requirementswill be removed from the site at the Contractor’s expense
2 Materials to be supplied by the Contractor
- All materials, appurtenances, fittings to be manufactured andincorporated into the permanent Works are new in accordance
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with the quality requirements as specified in the tenderdocuments and attached with the certificates issued by theauthorized agents.
- Before delivering the materials to site, the contractor willsubmit the samples, drawings, catalogues, chart or other data
of the materials to the Employer to prove that they meet therequirements for the project The submission of samples issubject to the Engineer
- Submission of materials indicates the origin, the supplier, thecontractual item number, the manufacturer’s certificates andother details as required in the technical specification
- The Contract obeys the Engineer’s request to carry outcalibration and checking quality The improper materials will
be removed out of the site at the expense of the Contractor
- Materials are transported and handled so as to avoid anydamages, and delivered in the dry condition without anydamage in unimpaired containers or packages of themaufacturers
- Materials are maintained in the recommendations of themanufacturers Some materials, which can be affected by theweather will be stored in the covered place with thetemperature and moisture as recommended by themanufacturer
- The materials stored outdoor are placed on the sloped platformover the ground and in the dry condition
X Works to be done in the nighttime
Some following works should be restricted to be carried out inthe nighttime
+ Placement of concrete to the important structures such asthrust blocks, erected and assembled members, etc
+ Soil improvement to weak soil
+ Pressure testing
The above- mentioned works could only be done in thenighttime with the prior consent of the Employer and the Engineer inwriting
The Contractor must pay the addional costs for the night-timeworks such as overtime cost and other amounts to the Engineer andthe Employer’s representatives
Working in the nighttime will comply with the regulations ofBinh Duong Province Construction Department
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XI Safety of traffic
For the pipeline to be constructed on the public roads, thecrowded resident area, the contractor will contact and getpermission from the concerned authorities before commencement.During the construction process, the contractor will take necessarymeasures to ensure the traffic safety such as supply of barrier,warning sign, signaling lamp
During the construction time, the Contractor will implementthe content of the Decision from Binh Duong Province People’sCommittee on the regulations for excavation and roadreinstatement
The road excavation activities on site are in such manner as toensure the safety of the works and workers If the trenches areexcavated with vertical sides, the contractor will take appropriatemeasures for soil consolidation such as driving concrete piles, steelsheet piles with the prior consent of the Engineer
The contractor will also pay attention to the care of water tomaintain the construction activities in the dry condition by thenecessary methods such as water drainage system for trench andexcavations in order to prevent any damage to the existing roadsand from the soil collapse
The road excavation must be done in such a manner as tomaintain the safety for vehicles and human such as erection ofoverpass bridge to avoid traffic jams
For pipe laying, the open trench is excavated partly in theperiod as specified in the design and tender documents Themaximum length of trench section to be constructed at the sametime does not exceed 300m in length The next section is onlycarried out after completion of pipe laying, installation ofaccessories, sand filling, and road reinstatement, pavement works.The final step is to contact with the traffic works management unitfor handing over the working areas
The excavated material is removed out of the working site andstored in the place approved by the Engineer and the concernedauthorities The excavated material is removed immediately in theperiod of a day from the working site and not scattered on the roadsurface
For the trench section through the road junction or cross, theroad surface with the minimum width of 2.5m is left for humantraveling or the temporary overpass bridge with the width of at least2.5m is erected using the steel structures for 2.5 ton trucks
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Temporary fence is installed during construction for safety andsecurity of the Works The temporary fence structure must be rigidand firm enough for the entire duration of the Works and incompliance with the State applicable regulations.
The contractor installs the signs at both ends of the Worksshowing the sufficient and clear information in accordance with theVietnamese Road Department’s regulation These signs andsignaling lamps are located with the sufficient numbers on siteaccording to the regulations for the day and nigh-time works Thepositions under settlement caused by the contractor must berecovered and repaired to prevent everybody from the trafficaccidents The signs and lamps are dismantled and removed uponthe completion of the Works The Contractor is fully responsible foraccidents happening on site during the construction
The contract must obtain the excavation and constructionlicenses from the concerned authorities prior to the commencement.The Contractor has to comply with the requirements onenvironmental sanitary and traffic safety regulations and ensure thedaily living activities for the residents around the Works
XII Protection of underground utilities and services
The contractor contacts with the concerned authorities related
to public works (electric power cable, water supply system, sewer,etc.) and coordinates with them to carry out removal of them orchecking the safety during the construction Beside that, thecontractor will assist to remove the storm water drainage andwastewater systems of the households around the Works if thesesystems affect the construction activities
The locations of the existing public facilities and servicesdetermined in the drawings are relative and only for reference Theinformation from these drawings does not release the Contractorfrom the contractual responsibilities and the contractor by himselfmake investigation and sure about the exact locations of theexisting works before the commencement The contractor makestrial excavations in the presence of the Engineer to determine theexact locations of the existing utilities prior to the excavation
XIII Safety for electric power wires and poles along the
construction routes
The Employer will carry out removing the electric power andtelephone system, the remaining facilities and systems near theextent of the Works that affect the construction activities must betaken care of by the contractor
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XIV Water drainage system to be provided in the working area
If the pipelines are constructed through the existing waterdrainage and sewerage systems, the contractor can not be allowed
to fill the sewers by himself but needs to construct the temporarywater drainage system to drain water of all kinds from thedownstream and takes necessary actions not to influence the life ofthe local residents around the working areas, especially in the rainyseason and to avoid water accumulation and pools in working areas
If required, the contractor can use the water pumps for the abovepurposes After pipe laying, the contractor will reinstate the existingwater drainage and sewage systems to the original state For theconcrete structures, the pipe laying is done in the dry condition
The Contractor will pump water or make temporary waterdrainage from the trenches for pipe laying or from the chambers forinstallation of blow-off valves in the dry condition The location anddesign of temporary water drainage trench are submitted andapproved by the Engineer
The temporary water drainage trench may be connected withthe existing drainage system Then, the contractor carries outbackfilling and compaction for temporary trenches with thesatisfactory of the Engineer
XV Access roads to factories, plants and residents’ areas
During pipe laying, the contractor does not make anyobstruction to the access roads and entrances to the factories, plant,the residents’ areas In case that the contractor uses the roads forconstruction activities, the contractor will construct the temporarydiversion road or bridge for traffic
XVI The additional works or variations
The additional work means the increased quantity of workscompared with the quantity in the tender documents due toobjective causes and design changes
During construction, any additional work or variation occurring onsite are recorded and treated in the specified procedure
While waiting for the completion of documents and approvalfrom the authorities, to ensure the overall construction schedule, thecontractor will follow the Engineer’s instruction to carry out theadditional works and variations immediately
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The additional works and variations are inspected and measured forpayment to the contractor The unit price is applied to thecontractual unit price or the rated price.
XVII Existing projects of the Employer
1 General:
- At present, there are many construction packages of thewater supply projects in Binh Duong Province The locations ofconnections are shown in the design documents and theContractor needs to check them before commencement of theWorks
- To ensure connection to comply with the technicalrequirements, the contractor must carry out pressure test forcompleted sections of pipeline in accordance with thetechnical requirements and then obtain the confirmation fromthe Engineer before undertaking the connection
- Before connection with the existing networks, the Contractorwill inform the Engineer and the Consultant and the Employer
to make general coordination with the other contractors toensure the overall construction schedule of the project
2 Connection with the existing system:
- Before connection with the other section, the section of thepipeline, which is constructed by the Contractor, must bechecked and inspected to confirm the quality requirements
- The Contractor must prepare and submit the detailedmethods for connection to the Engineer Upon receiving thewriting approval from the Engineer, the Contractor can carryout the work
3 Method and planning for connection:
- The Contractor must prepare the detailed connectionmethods and plan in order to prevent any damages or risks tothe operation of the existing pipelines
- The Contractor needs to describe his work and to submit theconstruction method, which he intends to execute to theEngineer for discussion and approval before hiscommencement of the work
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- His construction method must consist of all illustrative charts
as necessary and his clear statement Such his constructionmethod helps him to organize his construction activities wellwithout any misunderstanding and delay
XVIII Commencement Notice
The Contractor will give notice on the commencement dateand time to:
+ the local governments + the local residents and related parties in working areas.This notice indicates the natural of the project, some affectsduring the construction and name and address of the contractor forcontact in the emergency cases
XIX Health control
The Contractor provides workers with the safety workingconditions and health controls in accordance with the currentregulations The Contractor ensures to provide his staffs andworkers and the Engineer and the Employer with first-aid services onsite The standards on first aid and safety are in accordance with theregulations of Ministry of Health
XX Joint meetings
A weekly meeting between the key personnel of the Employer,Engineer and Contractor is held In case there is any problem, theEmployer or the Engineer can hold a sudden meeting with theattention of the authorized staffs from the Contractor at any time
XXI Construction inspection and management from the
upper levels (The Employer, Main Contractor)
During the execution of the project, the contractor isfrequently under the monitor and quality controls of the authorizedcompanies and parties as specified in the Decree Ref.52/1999/ND-
CP and 12/2000/ND-CP and their modifications The contractor givesthe good conditions and supplies the equipment and means to theparties to fulfill their duties This cost is included in the contractualunit price
Also, the Contractor are checked and controlled by the authoritiesregarding to the traffic safety and environmental management
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XXII Documentation on the quality and quantities of works:
Right after completion of each section or each work of theproject as required, the Contractor will complete and submit thequality or quantity documents with the reports of constructionresults to the Engineer, the Consultant and the Employer forinspection, confirmation
- Quantity Document (for inspection and payment): consists ofall records to check the geometric dimensions, levels and thebreakdown of quantities from the these measurement results
- Quality Document: consists of the quantity documents withthe surveying sheets and testing certificates in three stages
of construction (before, during and after the construction).The testing certificates are recognized by the lab inaccordance with the legal documents
XXIII Inspection Document and Report to the Engineer:
Based the above documents, the Contractor proposes theEngineer and Consultant to check his work and send the report tothe Employer for inspection:
- The Consultant/the Engineer checks the quantity breakdownfrom the Contractor and makes his report to the Employer toconduct the inspection
- The Consultant/the Engineer checks the quality certificates andmakes report to the Employer for inspection
XXIV Checking and inspection:
Based on the reports and proposal on inspection from theContractor, the Employer will hold the site inspection as follows:
- Inspection on the quantities of Works done in the monthlyprogress
- Inspection on the quality of works done before carrying out
next work: When the Contractor completes the pipe laying,before filling, he must carry out pressure testing
- All parties coordinate to inspect on site and make records forunderground works, soil improvement, concrete works, pipelaying in the day and night time, pressure test, roadreinstatement, etc These records are part of qualitydocuments
- For the other works, after completion, the Contractor and the
Engineer make site inspection and make records on site
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XXV Completion drawings (as-built drawings)
When completion of the Works, the contractor makes as-builtdrawings and documents This document includes all certificates onquality and quantity and approved drawings with the full explanation
in the time order as mentioned in the approved design documents.The cost for this submission is born by the contractor and is included
in the contractual unit rates Within thirty days after the receipt ofthe Taking over Certificates, the contractor will submit the EmployerA1 size as-built drawings, one set of diskettes containing completiondrawings in AutoCAD 2000 format, five bound sets of reduced size,clearly photocopied drawings with hard cover (A3 size) and fifebound sets of clearly photocopied, well complied documents withhard cover (A4 size)
The Employer makes the final payment to the Contractor whenthe contractor has completed as-built drawings and documents andreleases the retention money to the contractor at the expiry ofLiquidated Damages Period
XXVI Remedy work for defects during Liquidated damages Period
Liquidated Damages Period complies with the currentregulations, starting from the date of handing over the Works foroperation to the end of the period
The Contractor will carry out the remedy works for any defects,errors, and damages under the contractor’s responsibility within theliquidated damages period In case of more than 30 days after thenotice on the remedy work from the Employer, the contractor doesnot carry out repairing the defects as requested, the Employer hasthe right to assign the other party to do it and then deducts therepairing cost from the Contractor’s amount
XXVII Treatment of breaches
Any breach to this construction method is treated inaccordance with the laws, contractual conditions, maybe such asremoval, dismantle, rejection for inspection and payment, stopworking, removal out of the site
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Chapter 3 - SURVEYING & SETTING OUT
The following documents must be used for surveying and settingout
- General layout drawings;
- Design data
The following equipment and instruments must be redeay forsurveying and setting out: Theodolites, Automatic level, woodenbench marks (1.5m length), color paints, ropes, tapes, hammer,cutters, plades etc
a) Site work surveying
Firmly place and position the Theodolite at the bench markscontrolled and handed over by Employer, called as Mark A LetNorth seeing direction catch 0o angle to match with focusorientation Turn its focusing lenze with angle of 540o toward thework which need to be set out Set Mark B with steel tapefollowing the focus turned by 40m
b) Site work set point
Using tape to check its diagonals If its diagonals are equal, theset site work are true rectangle or square If its diagonals are notequal, it indicates that the set site works are in correct, whichneed to be corrected
After confirming the standard center points and its center lines,they are refered to some intermediate bench marks outside theworks where it shall be safely secured and protected Some otherpoint shall be specified upon the standard center line by singsteel tape and angle meters
c) Foundation setting out
Upon the standard set point, the surveyors erect the site marksboth side of the standard set line Ropes shall be used to set thelines The crossed points shall be used to set the work foundation.Site marks must be erected minimum 5 meters away fromfoundation limits Plastic ropes shall be used to create lines
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between the site site marks in order to specify the excavationlimits The excavation limits are marked on the ground by limepowder To protect site marks, it must be referred to anotherstandard marks outside the excavation area, which should bemark at elevation of +0.000 in RED Paints Ater excavation,center point and elevation of all foundation shall be final checkedand reconfirmed.
Basing upon standard points handed over by Employer, Totalsolutions Instrument shall be used to set-out coordinates andelevation, work center lines
Instruments used shall be modern and advanced equipment withhigh accuracy These instruments must be tested and certified byappropriate government authorities for use
Work elevation and center line shall be checked frequently byContractor’s surveyors during construction period
II Setting out the alignment and elevation of drainage
system
Based on the bench marks handed over by the Employer, theContractor will carry out surveying and setting out the works todeterminate the centerline and levels and coordinates of pipelines
The centerline of the pipeline is determined by the marksplaced in every 20m and at both ends of the pipe section, and thenecessary levels to the bottom level of the pipeline are provided inthe 20m intervals To ensure the accuracy along the route, themarks are fixed firmly on the stable structures along the route inorder to facilitate the installation and inspection during theconstruction process (These marks may be arranged on the walls orthe electric power poles along the pipeline route)
Equipment and tools to be used for the surveying work aremodern with the high accuracy and are checked and adjusted by theconcerned authorities and issued with the calibration certificatesbefore usage in the project
The positions of pipe centers and levels are frequently checked
by the site supervisors in order to minimise any damages orproblems, or mistakes during the construction
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Chapter 3 - Surveying work Page 24/89
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Chapter 4 - CONSTRUCTION METHOD
In-situ cast chambers
Final excavation (trimming)
Temporary structures, incl construction shaft, etc
Disposal/hauling of excavated materials
Backfilling
- Site preparation for the Sewerage TreatmentPlant include excavation of soft soil, disposal of excavated materials and filling by sand
- Earth works for construction of fence surrounding the Sewerage TreatmentPlant
- Earth works for temporary soil channels, reinforced concrete culverts and drainageoutlet
- All the earth works shall follow the approved Safety Plan and Environmental Management
- Sandy soil fill material shall be clean well graded sand, free of organic or other deleterious matter
- Filling the existing drain with sand or crushed stone
Natural areas is a network of small drainage ditch and a number of larger channels
All drainage ditches and larger channels were leveled with sand or crushed stone
to the elevation after topsoil removal
- Leveling the entire area with sand
After leveling the channels, filling the entire area is a thick layer of sand 0.50 m
- The other adjustments in the process of doing
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Ground surface is scratched continuously to ensure adequate contact with leveling material.
- If soil is too dry, water the soil needs.
If soil is too wet, it should be drained and dry soil.
The percentage, by weight in total material passed through the 0.075 mm sieve shall be less than ????
- Weighted uniform, D60/D10 not less than 4
- Option method: because the work site near the river therefore choose method of sand pumping from barge
- Execution of trial compaction
- Before Commencement of large scale embankment/filling, the Contractor shall undertake compacting trials on site The objective of the trials is to simulate the embankment/filling work in a small scale as a basis for determine the most
appropriate working methods to be used in large scale This means that the
Contractor shall use the same filling material, the same construction method and the same compacting equipment in the trials that will be used in the large scale filling
- The size of the trial area shall comprise 15 m2 (3x5m) as a minimum and the thickness of the spreading layers shall be 0.3 m
- The tests shall be executed in compliance with the following table:
Type of test Frequency of test
Laboratory tests
For every 0, 1, 2,
3, 5, 10, 15compactor passes
Specific gravity test
Grain size analyses
Moisture content test
Atterbergs’s limit test
Standard compaction test
Density test
- The results of the tests shall be submitted to the Engineer and the Contractors proposal of compaction method, based on the trials, shall be approved by the Engineer
- The approved method shall hereafter be applied for all Earth Works on site
- SPREADING OF BACKFILLING MATERIAL
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- Plain areas
- Before spreading a new layer of backfilling the Contractor shall adjust the last laid layer
- If the foundation is too dry, the foundation has to be sprayed by water
- If the foundation is too wet, the foundation has to be drained and dried
- The surface of the last laid layer shall be disturbed to ensure sufficient contact between the last laid layer and the new layer
- Add up ground on the top layer of soil
- To prepare for the future settlement, to an additional 15% elevation of the total height of land leveling on the top layer
- Compaction
- The number of compactor passes shall be carefully recorded by the Contractor
- If the compactor passes exceed 5 without having reached 90% Proctor, then a compaction test has to by undertaken The results of the test should be compared with results from the compacting trials
- DRAINAGE CHANNEL INSIDE THE PERIMETER WALL
- The Contractor shall excavate and form soil channels
- QUALITY CONTROL
- Stockpile Test
- The Contractor shall performed a test of material and submit to the Engineer for review and approval The test shall be following this table:
Type of test Frequency of test
Laboratory tests For every 500 m3 of
excavated soil and anychange of source of
Specific gravity test
Grain size analyses
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Moisture content test
Atterbergs’s limit test
Standard compaction test
3 test locations for every
500 m2 The tests shall beexecuted during one day
Minimum one test forevery activity
- The standard compaction shall be more than 90% Proctor Test
- If the test result complies with the requirements, the next layer can be placed
- If the test results do not satisfy the requirements, further compaction shall be madeuntil the standard compaction requirement is reached
- If the standard compaction requirements fail to meet the Requirements, the
Contractor shall change the compaction method (spreading thickness, compaction return times etc.)
Excavation works
Excavation work is done by backhoe excavator or front shovel have capacityconsistent with the volume of construction in each case, the land was dug upimmediately poured onto trucks and transported immediately from the constructionsite, the land transport vehicle will be promoted to the land not covered sand and othermaterials strewn along the the hauling route Digging ditches in size as designed, ifneed be expanded to ensure conformity with the soil compaction equipment availablefor the Contractor will not be additional cost
- Excavation materials will be transported from the site and brought to a placeprepared by the contractor with the approval of Engineer and other concernedagencies Excavated soil will be transported by truck to go as soon asexcavators, was not filled to spill into the street
+ Ensure safety for workers excavation operations
+ Measuring geometrical dimensions
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+ Load capacity of the ground (if the design documents required)
Compaction works:
- Compaction of soil, sand fill to ensure stability and limit the later settlement.The compactor will choose to pay attention to the characteristics and designrelative to a tube load of pipes or other structures beneath the land that achievethe best density requirements, before compacting equipment to site when getapproved by Engineer
- Landfill pass the test to satisfy the requirements to switch tofill the next layer
- Before and during compaction, compacted layer of material must havemoisture close to the optimum level for maximum compression withcompacted soil at least according to experimental results obtained at the site orthe prescribed standards will be filling and compaction up to 30 cm thick layers
to achieve the required density, density will be tested with number150m2/sample layer
- Select Excavator:
4./ FABRICATE AND FIXING OF FORMWORK
- Construction and installation of sheet metal formwork hinge joint Uand L
- Conducting plates mounted formwork is in the form of structuralfoundations, at the corner position for the corner of the plate
- Conducting the strut assembly and the transverse ring
- To facilitate the assembly process, form the foundation can be appliedfor before large panels as required size and then put down thefoundation pit
- Using crane combine with manually to bring formwork to the position of eachframework
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- When mounted crane lifting concrete slabs attention gently, to avoid collisionstrength for formwork disfiguring.
- Deficiencies in the position to insert wooden planks with a minimumthickness of 3cm
- Based on fix point on the ground, strung to take centerline and circumference of eachframework
- Fixing panels together with designed position by the guy wire anchors, anchor and standpile
- Before concreting formwork must be treated in a layer of anti-stick oil
- Using plane-table micrometer theodolite, steel ruler, plumb lines to examine thesize, position of frameworks
- Fixed formwork must be ensure stability, ensure the accuracy of size
5./ REINFORCING STEEL BARS FOR FOUNDATION
Specifications
a Fabrication
- Reinforced steel bars before processing and before concreting should ensure:surface clean, no sticky mud, no iron scales
- Reinforcement should be pulling, bending and straightening
- Reinforcement to be worked by hand at the reinforced workshop of the work,using extractor for bending iron, use scissors to cut iron, steel bars after cutting isfinished tied into bundles of the same type have a number of steel to effect avoidmistaken Reinforcement after processing completely will be transported to thesite by cart
- Steel bars were crushed, section reduced by the cleaning or by other causesexceed the limits do not allow the diameter is 2%, if it exceeds this limit, the type
of steel that is used by rest section
- Cutting and bar bending shall be made only by mechanical methods, the errorcurve for the cut according to norms
b Splices & tie reinforced steel bars
- Splices & tie reinforced steel bars: do not splice at great internal force positions
- On a cross section not exceeding 25% of the total area of reinforcement force isspliced (with plain round bars) and not more than 50% for deformed bars
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- Length of splices not less than 250 mm with tensile reinforcement and not lessthan 200 mm and compression reinforcement is taken under the norms.
- Splices in tension reinforcement should be bent hooks (plain round bars) and donot bend hooks with deformed bars
c Construction
- Parts previous erection does not hinder the erection of the following parts, shouldtake measures to stabilize the position so as not to cause reinforcementdeformation during concreting
- By design we sprayed layer reinforced lower down first and then spread theabove layer of reinforcing steel and tie at the intersections of two layers of steel.Request button is definitely not required to be reinforced design dislodged, notforce quit button
- Reinforcement are chocked up on chock 100 # of concrete to ensure thickness ofprotection layer, the chocks size 50x50x20 is located at the corner of thefoundation and center so that the distance of not greater than 1m, displacement ofeach bar when finished installation that does not exceed 1/5 of biggest diameterbars and 1/4 the diameter of that bar was, tolerance of not more than 50mm forreinforced foundation
- Steel bars waiting to be installed in the columns shall be installed first and thelength of waiting steel bars > 30d
d Inspection of test
- Before proceeding with construction of concrete, reinforcement must be takeninspection of test includes:
+ Reinforcement diameter, shape, size, location, quality of each splice, the number
of reinforcement, spacing of reinforcement design
+ Protective layer thickness, grade of concrete …
- Must specify the date and time of testing, acceptance documents must be filed forconsideration during the construction process later
6 CONCRETE WORKS
a Select construction equipment
- After complete install formwork of foundation we process concreting foundation,with large volumes of concrete, so we used commercial concrete
Selection of vehicles carrying commercial concrete
SB-92B CODE NAME HAS FOLLOWING SPECIFICATIONS
Tank
capacit Automoti Water tank Engine mixing tank rotation waste concrete pumping
Trang 32y (m3) ve facility capacity(m3) Power(KW) speed (r/m)
dump height
- Weight ( with concrete ) : 21,859(T)
- Speed (asphalt road) 70km/h
Calculate the number of vehicles needed to concreting
SELECT CONCRETE PUMP Putzmeister M43 WITH FOLLOWING
SPECIFICATIONS
Height(m)
width(m)
Depth(m)
Length (fold)(m)
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Cylinder length (mm)
Cylinder diameter (mm)
- The advantage of using the pump in construction is large volume, fastconstruction time, ensuring the technical quality, reduce beaded joint, ensuringquality of concrete
Selection of concrete vibrator
- Select spud vibrator: Type U 21-75 with following spectifications:
+ Compaction period: 30 sec
Trang 34- Concrete foundation work is divided into two phases:
+ Concreting foundation framework: after placing blinding concrete, we redefine
center axis, framework level, installation of reinforcement, formwork and conduct
concreting
+ Concreting braced foundation: after completion of foundation framework
construction work we proceed to the landfill pit up to bottom elevation braced
foundation (braced foundation elevation at 0.9m compared with cos + 0000) conduct concreting braced foundation, installing reinforced steel, formwork and proceed to
place concrete bracing
a Preparatory works
- Acceptance of formwork, reinforcement before concreting
- Clean foundations
- Coat oil for anti stick between concrete and formwork
- Check the slump of concrete, cast in the field samples to test
b Placing and compactation of foundation concrete
- Commercial concrete is conveying by specialized vehicles, via a funnel intopump equipment
Water tank capacity
(m3)
Engine Power
(KW)
mixing tank rotation speed (r/m)
waste dump height
(m)
concrete pumping time (min)
For ready-mixed concrete, concrete time allowed by the factory from time to
concreting does not exceed 2 hours
- Slump of the concrete pump machines from 12 to 16cm Is determined as
follows; use frame truncated cone bottom diameter 20 cm large, small bottom 10 cm,
30 cm high, placed on board a large flat bottom and upside down
- Concrete transferred to the site must be stir, then take out into the Abraham’s cones, prod used to make concrete compactive, then withdrawal of vertical truncated cone Part of concrete that will flow, the height will decrease, stop waiting for
concrete to reduce height, a measure used to determine concrete will fall down to how many cm
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- Check against back-shore, power, equipment last time before concreting.
- Concrete foundations were placed by pumping methods, workers have arranged at positions on the floor and under the pit, we pour into each layer thoroughly compactedand then pour the next, workers should be combined with the concrete pump to the performance is good
III./ CONSTRUCTION OF CONCRETE UNITS
1./ CONSTRUCTION METHOD:
a Purpose:
One very important criterion in construction is process of works Constructionprocess showing the level of technology and the level of modern ofconstruction organization
Construction process depends on many factors, such as modern constructionequipment such as: The cranes can reach great heights and can be applied in thenarrow terrain, the high level of mechanization, the high strength material Advanced formwork construction technology, other additives and fast settinghigh strength
Trang 36vertical bracing in two ways.
c Concrete construction technology:
Due to using high grade concrete so using concrete mixing and placing in-situ isnot an economy way, otherwise quality of this concrete is unstable, it is verydifficult to achieve high grade Choose the method of construction incommercial concrete
3./ SELECTION OF CONSTRUCTION EQUIPMENT:
a Selection of formwork, back-shore:
* Selection of formwork:
Using metal formwork manufactured by Japanese steel company NITTETSU (the technical characteristics of the metal form was present in the foundation
construction work)
* Selection of back-shore for formwork of bottom beam:
Using single metal back-shore
* Selection of braced member for support formwork:
b Vehicle of transport up:
4./ SPECIFICATIONS:
a Specification for formwork, scraffold, back-shore:
- Installation:
Ensure proper shape, designed size of structures
Formwork, scraffold must be designed and constructed to ensure hardness, stability,easy to remove without causing difficulties to the reinforcement, concrete placing and compacting
Formwork must be installed closely tightly so as not to lose water cement
Formwork contact with concrete needs to be coated with oil to preventadhension
Formwork edge of the texture of the walls, floor, beam, column shall beinstalled to match the early removal without affecting the scraffold left for support.Stanchion of scraffold must be placed firmly on a hard surface without sliding,distortion and deflection when loaded in the construction process
During the installation process of formwork, needs the appropriate number ofholes at the bottom to the surface when cleaning dirty water and debris out Beforeconcreting the holes must be sealed
- Removal of formwork, scraffold:
Formwork, scraffold were removed only when the concrete reaches the strengthneeded to withstand the weight of the structure itself and other construction loads
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When remove formwork need to avoid sudden stress or strong collision damage to thestructure itself and the surrounding structures
The formwork, scraffold no longer bearing after concrete hardened and can beremoved when the concrete intensity reached 50daN/cm2
When remove formwork, scraffold in the floors of the monolithic many floorsshould do as follows:
Keep all scraffold and stanchions in the adjacent slab beneath the floor ready toplace concrete
- Remove by parts (removing 50%) of the stanchions, formwork in the bottom slabs again and keep safe stanchions spaced 3 m under the beam span> 4m
The partial loading on the structure after removal of formwork, scraffold should
be calculated according to concrete strength has reached, and the types of structuralcharacteristics of the load to avoid cracks and other damage to structures The highload on the entire structure was removed all the formwork, scraffold only done whenthe concrete reached design strength
b Specifications for reinforcement :
Before placing concrete have to make reinforcement test record includes:
- Technicians of the unit directly managing the project management and
technical staff of the constractor
* The basic content of the work should be accepted:
* Steel grade, diameter, shape, size, location and quality of each splice, the number and spacing of reinforcement as designed, the junctions, splices details available buried, waiting holes or structural requirements and other special details
* Thickness of protect concrete cover
- Specify the date and time of test, then all the test participants must sign the record If changes must have the consent of the engineer
c Specifications for concrete mortar:
Concrete mortar should be mixed thoroughly to ensure uniformity ofcomposition Shall to be achieved designed grade
Mixing time and transportation, placing and compacting shall ensure quality,avoid concrete setting
d Specifications for concrete pumping works:
Pumping must to be operating continuously When need to stop for whateverreason, then every 10 minutes to pump concrete to avoid clogging pipes
If the pumps have to stop over 2 hours they must through the tube with water
Do not stop for too long When finish pumping, water used to clean pipes
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e Specifications for concreting:
Not to displacement the position of reinforcement, and positions formwork andthickness of reinforced protection
Concrete must be placed continuously until completion of a certain structure inaccordance with the design
To avoid segregation, the height of free fall of concrete to place the should notexceed 1.5 m
When concreting is in free fall from height> 1.5 m shall use chute feeder ortube If the height > 10 m had to use tube with vibro equipment
When placing concrete shall pour from far to near place from the receivingposition Place from the top to down
Concreting columns should be placed continuously
Do not use needle vibrator to move compacted concrete
Horizontal construction joint should be placed in position by height offormwork Before placing new concrete to make rough, moisten the surface of oldconcrete must then step on how to firmly attach the new concrete layer to ensure theold concrete piece of the structure
Concrete:
- Must be mixed thoroughly to ensure uniformity of composition.
- To achieve the designed strength.
- Make sure mixing time processing, transportation and casting concrete within specified limits, the time that the process lasts, the quality of mortar and
Trang 39concrete are reduce that unusable.
- Mortar mix must meet certain requirements of construction such as to have a certain level of mobility to be able to quickly pour off the mortar mix, from transportation, to be poured into molds faster, be filled all interstices between the reinforcing bar.
+ Curing and removal of formwork:
Trang 40formwork Watering time depending the weather and type of cement, usually in about 7 14 days.
- After casting concrete do not step on and put formwork on, install scraffold and make strong impact on the concrete before it reached strength 25(kg/cm2) (in winter after 34 days, in summer after 1 2 days).
- In general, order of remove formwork is: install later, remove first and install first, remove later.
+ Repair of concrete defects:
* Porosity:
+ Honeycomb: only are small holes on surface but not into the reinforcement
+ Deep poros hole: Deep porosity was until reinforcement.
+ Penitrant poros : through from the side to the other side
- Due to compact not carefully, not steadily or are using vibrating
compactor is too weak.
- Due to using aggregate not meet specifications, dry concrete mix does not steadily, means of transport not in closed make loss cement water.
* Repair:
- If it is honeycomb we use a type wire brush the old coat, wipe and clean by water, waiting for a dry then using higher grade cement grout to coat.