J-1-1_TECH_SPECIFICATIONS.pdf

TECHNICAL SPECIFICATIONS

E-00319 - MAG MONITORING

CENTER

February 2019 i

Content

C1. GENERAL DESCRIPTION

C2. SPECIFIC TASK

Preliminary work

Building Retrofit

Electrical system

Drinking water systems

Waste and storm water systems

Fire detection system

Telecommunications system

Air Conditioning & Ventilation

C3. GENERAL SPECIFICATIONS

Quantities

Trials and Tests

Work Execution

Cost of the Project

C4. TASK SPECIFICATIONS

Preliminary Work

C4.1.1 Land clearing

C4.1.2 Leveling and plotting

C4.1.3 Warning Signs

C4.1.4 Temporary Structures

Earthwork, Excavation and Backfilling

C4.2.1 Leveling and land clearing

C4.2.2 Excavation

C4.2.3 Over-excavation

C4.2.4 Conglomerate and rock removal

C4.2.5 Excavation with water presence

C4.2.6 Removal of water and/or excavated Material

C4.2.7 Backfilling ii

C4.2.8 Compacted backfilling with natural soil

C4.2.9 Compacted backfilling with granular material

C5. CONCRETE

General

Properties and characteristics of concrete

C5.2.1 Applicable publications

C5.2.2 Cement

C5.2.3 Sand (fine aggregate)

C5.2.4 Gravel (coarse aggregate)

C5.2.5 Water

C5.2.6 Additives

C5.2.7 Hand mixing

C5.2.8 Mechanical concrete mixer

C5.2.9 Mixing while in transit

C5.2.10 Sleeves in concrete

C5.2.11 Anchors and fittings

C5.2.12 Construction Joints

C5.2.13 Concrete casting and vibration

C5.2.14 Concrete strength

C5.2.15 Strength testing

C5.2.16 Test approval

C5.2.17 Concrete curing

C5.2.18 Concrete defects reparation

Formwork

C5.3.1 General

C5.3.2 Wood Formwork

C5.3.3 Plywood formwork

C5.3.4 Metal formwork

C5.3.5 Other materials

C5.3.6 Formwork construction

C5.3.7 Non-exposed concrete formwork

C5.3.8 Formwork erection

C5.3.9 Formwork removal iii

C5.3.10 Formwork reuse

Reinforcement Steel

C5.4.1 General

C5.4.2 Reinforcement Steel bars

C5.4.3 Welded Steel mesh

C5.4.4 Annealed wire (tie wire)

C5.4.5 Reinforcement fabrication

C5.4.6 Fabrication tolerances

C5.4.7 Placement tolerances

C5.4.8 Samples and testing

C5.4.9 Storage

C5.4.10 Hooks and bends

C5.4.11 Reinforcement cleaning

C5.4.12 Rebar placement

C5.4.13 Supports

C5.4.14 Inspection

C6. MASONRY

Applicable publications

General

C6.2.1 Handling and storage

Materials

C6.3.1 Concrete Masonry Units

C6.3.2 CMU mortar

C6.3.3 Sand

C6.3.4 Water

C6.3.5 Concrete fill

CMU walls

C6.4.1 General

Mortar preparation and CMU cell filling

C6.5.1 General

C6.5.2 Dosage

C6.5.3 Mortar

C6.5.4 Mixing iv

C6.5.5 Masonry erection

C7. METALS

Applicable publications

General

C7.2.1 Approval requests

C7.2.2 Structuration

Metal fabrication

C7.3.1 Material handling

C7.3.2 Resistance and specifications

C7.3.3 Materials

C7.3.4 Fabrication and labor

Construction and assembly

C7.4.1 Fabrication and mounting

C7.4.2 Reference standards and materials

C7.4.3 Joints

Welding

C7.5.1 General

C7.5.2 Welding procedures

Metal surface finish

C7.6.1 General

C7.6.2 Work that must be done in shop

C7.6.3 Work that must be done on-site

Erection and assembly

C8. WALL FINISH

General

Surface preparation for plastering

C8.2.1 General

Fine plaster

C8.3.1 General

Tiling

C8.4.1 General

Paint and Coating for Walls

C9. SEALANTS AND WATERPROOFING

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Sealants and water repellants

C10. FLOORS

Broom Finished Concrete

Sidewalk floors

Tiling

C10.3.1 General

C11. PAINTING

General

Storage

Labour

Surface preparation

Samples

Materials

Cleaning

C12. MECHANICAL INSTALLATIONS

Applicable publications

General

C12.2.1 Approval requests

C12.2.2 Samples

C12.2.3 Drawings and specifications

C12.2.4 Scope

C12.2.5 Approval

C12.2.6 Brands and models

C12.2.7 As Built drawings

Construction

C12.3.1 Equipment and material management

C12.3.2 Materials

C12.3.3 Supports

C12.3.4 Installation considerations

C12.3.5 Tests

C12.3.6 Work reception

C12.3.7 System performance guarantee

Protection vi

Potable Water System

C12.5.1 Potable Water Connection

C12.5.2 Water Interior Network

C12.5.3 Pipes and Accessories

Stormwater and wastewater

C12.6.1 General

C12.6.2 Approvals

C12.6.3 Pipe installation for external work

C12.6.4 Pipe installation for interior work

C12.6.5 Accessories

C12.6.6 Tests

Sanitary Devices

C12.7.1 Installing Sanitary Devices

C12.7.2 Washbasins

C12.7.3 Toilets

C13. ELECTRIC SYSTEM

Electric Distribution Boards

Illumination

Power Outlets

Ground Net

Conduit System

Pipes

Boxes

Conductor

C14. TELECOMMUNICATIONS

GENERAL

C14.1.1 SECTION SCOPE

C14.1.2 DOCUMENTATION TO BE PREPARED

C14.1.3 SYSTEM DESCRIPTION

PRODUCT

C14.2.1 OPTICAL FIBER

C14.2.2 UTP CATEGORY 6 CABLE

C14.2.3 CONNECTORS (JACK) RJ45 CATEGORY

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C14.2.4 PLATES FOR TELECOMMUNICATIONS OUTLETS

C14.2.5 COPPER PATCH CORDS

C14.2.6 CONNECTION RACKS

C14.2.7 PATCH PANELS

C14.2.8 NETWORK SWITCH

C14.2.9 WIRELESS ACCESS POINTS

C14.2.10 BASKET TRAYS

C14.2.11 PDU’S

EXECUTION

C14.3.1 INSTALLATION

C14.3.2 GROUINDING AND ELECTRICAL BONDING

C14.3.3 IDENTIFICATION AND MANAGEMENT

C14.3.4 WIRING TESTS AND CERTIFICATION

C14.3.5 QUALITY CONTROL

C15. FIRE DETECTION SYSTEM

GENERAL

C15.1.1 SECTION SCOPE

C15.1.2 REQUIREMENTS AND REGULATIONS

C15.1.3 DOCUMENTS TO BE PREPARED

C15.1.4 SYSTEM DESCRIPTION

PRODUCT

C15.2.1 INITIATION DEVICES

C15.2.2 NOTIFICATION DEVICES

EXECUTION

C15.3.1 INSTALLATION

C15.3.2 QUALITY CONTROL

C16. MINI-SPLIT TYPE A/C EQUIPMENT

GENERAL

C16.1.1 SUMMARY

C16.1.2 REFERENCES

C16.1.3 SUBMITTALS

C16.1.4 CLOSURE SUBMITTALS

C16.1.5 QUALITY ASSURANCE

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C16.1.6 STORAGE AND MANIPULATION

C16.1.7 WARRANTY

PRODUCT

C16.2.1 GENERAL

C16.2.2 UNIDADES TIPO MINI‐SPLIT

C16.2.3 THERMOSTATE

C16.2.4 PERFORMANCE / DESIGN CRITERIA

C16.2.5 REGRIGERANTS

C16.2.6 REFRIGERANT PIPES

C16.2.7 CONDENSATE DRAINAGE PIPES

C16.2.8 PIPE INSULATION

EXECUTION

C16.3.1 INSTALLATION

C16.3.2 EXISTING CONDITIONS

C16.3.3 SUPPORT

C16.3.4 TEST, CLEANING AND DEHYDRATION (REFRIGERANT LINES - LR)

C16.3.5 CONTROL SYSTEM

C16.3.6 CLOSURE ACTIVITIES

C17. OTHERS

Doors

C17.1.1 General

C17.1.2 Fittings

C17.1.3 Wood doors

C17.1.4 Metal doors

Window system

Roof cover

C1. GENERAL DESCRIPTION

The Embassy of the United States of America, in cooperation with the Costa

Rican “Ministerio de Agricultura y Ganadería” is heading an infrastructure project consisting in the retrofit of a building to be used as a monitoring center.

The overall intent of the contractual effort for this project is to make improvements to the existing infrastructure as follows:

1- Preliminary Work

2- Building Retrofit

3- Electrical system

4- Drinking water systems

5- Waste and storm water systems

6- Fire detection system

7- Telecommunications system

8- Air Conditioning & Ventilation

The project will be built using Estruconsult’s design, presented in drawings. The existing facilities are located in Santa Rosa district, Santo Domingo canton, Heredia province, Costa Rica.

The project shall be conducted in accordance with the plans and specifications detailed in this document.

C2. SPECIFIC TASK

Preliminary work

Preliminary work includes the implementation of temporary facilities for the workers according to the specifications detailed in C4.1.4.

The preliminary work shall also include a technical review of the designs technical specifications in order to comply with all the established requirements.

The Contractor will also be in charge of obtaining construction permits from the appropriate local authority (Santo Domingo municipality). The Contractor shall therefore provide all the qualified technical staff in charge of the project’s development in accordance to local regulation, based on provided designs, drawings and this document’s specifications.

Building Retrofit

The building to be retrofitted is located in the south side of the general plan, as shown in drawing C1.1, which is currently used as an office. The scope of work to be performed by contractor includes, but is not limited to: roof structure and cover replacement, replacing ceiling, placing new floor tiles, demolishing certain walls and building new concrete walls, plastering and repainting existing walls and new walls, replacing existing doors, replacing certain windows and building protections, etc… All of this, as indicated in drawings:

D-A1.1 to D-A1.2

D-S1.1.

AR-1.1 to AR-3.5.

SR-1.1 to SR-6.2.

The furniture to be provided by the contractor is specified in sheet AR-1.3. The contractor must not consider furniture and equipment to be supplied by INL, as indicated in the same sheet.

Electrical system

The contractor shall build the electric system to meet the complete requirements identified in drawings ER-1.1 to ER-1.7 and according to the Local Electric Code.

This work must be performed under the supervision of a certified professional

(Electric Engineer).

The internal and external electric system of the buildings shall be totally reconstructed; therefore, the contractor shall build it according the complete requirements identified in the drawings cited above.

The electric supply for the building shall be from one of the electric transformers located in front of the property. The supply will travel underground, using the detail shown in sheet ER-1.1. For this, the Contractor must take into account the work required to uninstall all existing electrical connections in the electric transformers and installing new wiring and canalization. Contractor must acquire a new power meter for the building(through the National Power Company, CNFL) and build the appropriate concrete column for placing the meter and the main interruptor, as shown in sheet ER-1.1.

Contractor must also consider the uninstalling and installation of new wire and canalization, as well as acquiring the power meter, for the existing DFSE laboratory building, located in the property’s south-east corner (as shown in sheet C1.1.)

The final connection from the electric supply to the main electric boards shall be as specified in sheet ER-1.8, using wiring 2#4/0 AWG THW, 1#3/0 AWG THW for neutral and 1#2 AWG THW for grounding.

The electrical system will also include a 75 kW, 120/240V emergency power generator with automatic startup, as well as a 3P2T, 120/240V, 225A automatic transfer switch, a backup 20kva UPS and a 3P2T, 120/240V, 100 A manual transfer switch for the UPS’s maintenance, as shown in sheet ER-1.8.

The contractor must consider any permits, and their associated costs, required for the completion of the electrical connection to the power supply.

Drinking water systems

The contractor shall build the drinking water system necessary for function of the building, in accordance with mechanical drawing MR-1.2. PVC piping and associated connections, must comply with this specification and follow each manufacturer’s manual indications.

The Contractor shall provide, place, connect, fix and test all the pipes, accessories and special items, as well as the required valves, which together will serve to conduct potable water. The potable water will come from the public service, thorough the existing connections.

Waste and storm water systems

The contractor shall retrofit and build all the necessary mechanical systems necessary for the complete function of the building, including the rainwater system, a greywater system and a wastewater system. All of these according to mechanical drawings MR-1.1 and MR-1.3. PVC, aluminum, and any other type of piping and associated connections, must comply with this specification and follow each manufacturer’s manual indications.

The Contractor shall build the sewage system, for the bathrooms located in the building, as well as for the kitchen lavatory, and shall provide, place, connect and satisfactorily test the pipes, revision points, and other devices of the entire sewer system. Requirements include the connection of the new pipes to the existing septic tank (see drawing C1.1).

Contractor must also build a new storm-water system, which will include a pump system, so that flooding does not occur in the monitoring center or adjacent buildings. The storm water system will evacuate to the street, as shown in sheet

MR-1.1, by means of two pumps which will work either simultaneously or alternating, depending on the amount of storm water and the water level inside the retention tank. The pumps will be equal or superior to LEH200 Series of the

Liberty Pumps brand.

Fire detection system

The fire protection system includes ABC type extinguishers and a fire alarm system with smoke and heat detectors, strobe lights and manual stations, which will be built and installed in accordance to drawings AR-1.7 and AR-1.8.

Evacuation routes and signage are also indicated in these drawings.

The contractor shall build this system according to the mentioned drawings and shall include the equipment, cabling and canalization for the Fire Protection system according to the specifications, so that at the end of the required work a fully functioning fire protection system is delivered.

Smoke detectors will be NP-100 (A), heat detectors NH-100R, manual alarm stations NOT-BG12LX, strobe lights SpectrAlert Advance P2RA, and control panel

Firewarden-50 (E) of the NOTIFIER series by Honeywell or superior brand. All systems must be from the same manufacturing house and fully compatible. The system will include a 12V back up battery and a transient voltage suppressor for the main panel.

The fire alarm system will comply with the Manual De Disposiciones Técnicas

Generales Sobre Seguridad Humana y Protección Contra Incendios 2013, as well as the applicable NFPA standards as indicated by the manual.

Telecommunications system

The contractor shall build the telecommunications system to meet the complete requirements identified in drawings E1.6, and E1.8 and according to the specifications provided in this document. This work must be performed under the supervision of a certified professional.

The installation of the fiber optic up to the project’s IT room will be the responsibility of MAG (Ministerio de Agricultura y Ganadería, owner of the property). The final connection from the fiber optic to the telecommunication´s equipment will be the responsibility of the Contractor.

Air Conditioning & Ventilation

The A/C system will be built based on these specifications and drawing ER-1.4, in building areas 100, 101, 102 and 400, as shown on the specified sheet. The

Contractor shall consider a mini-split system, comprising evaporator and condensing units, which will be completely new.

C3. GENERAL SPECIFICATIONS

All work shall be carried out in strict compliance with all contract clauses and these technical specifications. In the event that the Contractor discovers discrepancies contained in the various design/technical documents, Contractor must immediately notify the Contracting Officer Representative (COR) before taking any other action.

Quantities

This contract is based on a lump sum priced solicitation. Any quantities indicated in the specifications and drawings are for reference only and the Contractor is responsible for providing quantities needed to complete the work, without any price adjustment after award.

Trials and Tests

Materials, permanent equipment, its accessories and other elements used in the project, shall be subject to tests necessary to verify their compliance with specifications, properties and characteristics, in accordance with the specified requirements and tolerances, in line with the use for which they have been intended.

Materials, equipment, accessories or elements that have not been accepted by the COR (Contracting Officer Representative), shall be withdrawn from the work site or replaced, at Contractor’s cost.

Laboratory tests can be carried out, according to the specific case, at the work site or in laboratories previously authorized by the COR. Materials that bear quality certificates issued by ISO or its equivalent, do not need to be routinely tested. Costs of laboratory trials and tests shall be for the account of Contractor.

The COR shall be able to carry out special trials and tests at any time if it is needed to clarify the quality of any item.

Work Execution

The different items in the construction schedule shall be carried out in a gradual and progressive manner, without starting any work that could later be affected by other items that have not been concluded or that lack an adequate support or safety measures, taking care that work that has been finished is not affected by weather or other elements.

The Contractor shall be responsible for maintaining quality of work by following proper operation procedures in construction.

Throughout the different stages of construction work, Contractor shall obtain approval, from the COR, in order to continue with subsequent stages of construction. Before receiving approval to continue through the various stages, samples of completed work shall be tested to verify the quality of the work.

The Contractor shall provide a construction schedule in which all the works shall be detailed with the date of performance and delivery.

Cost of the Project

The Contractor shall include all the costs of the materials, labor, transportation, and materials testing that will be needed to complete the project and comply with all the specifications stated in this document.

C4. TASK SPECIFICATIONS

Preliminary Work

C4.1.1 Land clearing

This clause includes tree trimming work (any required permissions apply) and any shrub, trunk, root, grass and topsoil layer removal. The aim of this is to clear the area on and around the building’s footprint that is deemed unsuitable for foundation work or terrain leveling works.

The Contractor shall perform any land clearing, root, tree and vegetation removal, and topsoil and organic silt elimination when present. Any elements that interfere with the construction work, such as old foundations, rocks, etc., must be removed by the Contractor. All of the materials removed from the project’s site, such as topsoil and debris, must be transported by the Contractor and disposed of in an appropriate place outside the property, which selection, along with any implicit technical and environmental repercussions, is the

Contractor’s responsibility

C4.1.2 Leveling and plotting

Before construction start, the Contractor shall define the project’s components layout and, if necessary, construction levels in accordance to the provided drawings. During this same phase the Contractor must verify all of the drawings information, and correct them if any discrepancy exists between real, on-site, dimensions and those provided in drawings by the designer.

To comply with these requirements, the Contractor shall provide an expert topographer supported by precision equipment such as: total stations, levels, measuring tape, and any other required equipment for layout, alignment and terrain leveling. The use of this equipment will be performed so that machinery works will not interfere. Any additional alignment or leveling job cost will be the

Contractor’s responsibility.

C4.1.3 Warning Signs

The Contractor shall provide all the necessary signs and announcements to prevent accidents according to the safety plan, which shall have the approval of the COR. Signs shall be made of acrylic or galvanized sheets painted with a yellow background and with red or black letters.

C4.1.4 Temporary Structures

Temporary structures, for the Contractor’s personnel use, will be implemented for use during the project’s duration. It is the Contractor’s responsibility to implement offices, warehouses, provisional bathrooms and the guardhouses required for their own use, with a temporary connection to a potable water and sewage system prior to commencing construction. One sanitary facility shall be implemented for every ten workers, with an additional one for the technical staff.

The Contractor will be responsible for cleaning and maintaining these structures.

The materials used for these provisional facilities can be metal, concrete, or wood, as long as they are secure and provide a private area. The COR can demand changes or improvements of the provisional facilities at any time if he determines that the Contractor is not providing a clean area with sufficient privacy and safety.

Earthwork, Excavation and Backfilling

The work described in this chapter includes excavation and backfilling, as well as carrying, piling up and removing excavation material necessary for the construction of the building, piping, and all elements indicated in the project drawings.

C4.2.1 Leveling and land clearing

To determine final levels, theodolites or precision instruments will be used. If there are considerable differences with the specifications in the drawings, the

COR shall be notified and only through a report of mutual agreement will the new levels be determined.

The residual material must be removed and placed outside the construction site in places approved by the local authority.

C4.2.2 Excavation

Generally, excavation is understood as the removal of volumes of land or other materials for the purpose of forming spaces for construction, foundations, structures, buildings, roads, etc. Excavation shall be done according to the heights, limits, elevations, gradients and sections set forth in the structural, architectural, and sanitary drawings, save for different or real conditions of the project.

During excavation, material satisfactory for backfilling shall be stockpiled in an orderly manner at a distance from banks of the trench equal to ½ the depth of the excavation, but in no instance closer than 60 cm. Excavated material not required or not satisfactory for backfill shall be removed from the site, without affecting the adjacent properties. The material produced from excavation will be temporarily disposed of on the sides of excavations, so that it will not impede the execution of other work.

The final excavation that will be performed in the places where specific exterior works made out of concrete will be built, shall be carried out as close to the pouring of concrete to avoid any alterations due to bad weather.

In no case shall excavation be performed to a depth in which the soil is loose. If this happens, it will be considered as an “over excavation” that will be corrected by the contractor according to the project’s specifications.

If, in the Contractor’s or COR’s opinion, the bottom of the ditch is not strong or is unstable, over-excavation will be carried out until solid ground is reached, otherwise another solution shall be jointly agreed upon by the Contractor and the COR.

It is the Contractor’s duty to protect the stability of the adjacent properties while excavation is carried out. This should be done in a way that guarantees the stability of those buildings without causing any damage.

Excavation shall be protected against rain, landslides and other excavations.

The Contractor will protect the personnel excavating in ditches and, if for safety reasons it is deemed necessary, the contractor shall provide timbering and shoring.

This shoring shall be reviewed and approved by the COR, and the Contractor will protect the shoring and will be removed after the excavation has been performed.

For piping placement in excavation, the filling will be laid as a first step to cover a height of at least 20 cm above the highest part of piping and shall be compressed in accordance with the article of this section. Excavation will be done from the ditch in accordance with the gradient slope and required transversal lines for placement of piping as indicated on working drawings.

C4.2.3 Over-excavation

The term over-excavation, for the purposes of the job to be carried out, is understood as excavation outside the lines and levels set forth in the drawings, the specifications and/or the COR’s instructions.

If over-excavation is done, removal should go up to the required level and filling with soil, granular material or concrete or any other material approved by the

COR; compressing will be done with adequate water content, in layers that will not exceed a thickness of 15 cm, using an appropriate mechanical compactor.

The compaction process shall be done according to the regulations established by the standards of the American Association of State Highway and

Transportation Officials (AASHTO T-130). The material to be used shall be selected granular material according AASHTO 145.

The Contractor agrees not to receive any additional payment for over-excavation that may result from the conditions of the land, the action of natural agents, operations that are executed to facilitate the construction, and mistakes made by the Contractor.

C4.2.4 Conglomerate and rock removal

The process of excavation when hard materials are found which cannot be loosened through ordinary methods is understood as conglomerate and rock excavation where the use of shovels, pickaxes, backhoes, or excavators is not sufficient and explosives, mechanical hammers, wedges, or sledge hammers or other similar are absolutely necessary.

If a rock is found in pieces, only fragments greater than 200 cubic decimeters will be considered as rock.

When removing rock or masonry fragments from a ditch is necessary, and if they form clusters that do not have to be totally extracted in order to erect structures, those pieces excavated within the presumed boundaries will be considered as rock, although their volume could be smaller than the one indicated in the above paragraph.

If the bottom of the trench (made to install pipelines) is made up of conglomerate or rock, excavation will be carried out up to 0.15 m below the seat of the pipe and it will be filled later with sand and fine gravel.

When excavation is carried out on fixed rocks, the use of explosives will be allowed, provided that they do not alter the land adjacent to the excavation works and with a prior written authorization from the COR.

C4.2.5 Excavation with water presence

The excavation with presence of water may be caused by water coming from the underground, rainwater, floods, operation of the construction, sewage and others.

Excavation cannot be executed in the presence of water, whatever its origin, and therefore due precautions and protections must be taken, as construction techniques advise in these cases. The presence of water makes work more difficult and the safety of the people and the projects themselves decreases.

Therefore, the Contractor is required to take due precautions to eliminate water in excavation sites by using stake boards, cofferdams, pumping, drainage, curbs, etc.

When placing stone masonries, concrete structures, or any structure, the

Contractor will insure that water is not present in excavations, and that it will remain so until mortar and concrete have set.

None of the excavations should have water present before placing the pipes, and under no circumstance will they be placed under water. The trenches shall remain dry until the pipes have been totally coupled and the welded junctions are completely dry.

C4.2.6 Removal of water and/or excavated Material

Waste removal is defined as the method of transportation of the materials produced by excavation, which should have a specifically determined place for disposal approved by the local authority.

When there is an excess material, the Contractor shall remove it and place it outside the area of construction where such material will not obstruct watercourses or cause detriment to the neighboring areas.

Excess or waste material should not be located in properties adjacent to the construction site unless the Contractor receives written authorization from the owners of such properties.

The material produced by excavation that will not be used for the construction of the project shall be removed from the site using heavy mechanical equipment in good condition, without causing vehicle transit interruption or neighbors’ annoyance.

C4.2.7 Backfilling

Backfilling is defined at the sections indicated by the project, the existing gaps between structures and excavations, or between the structures and the natural soil in such a way that any point of the finished section will remain at a distance greater than 10 centimeters from the corresponding section of the project. The backfilling process will be carried out using earth, gravel, sand or rock with approval from the COR.

Prior to backfilling, the land shall be free of debris, trunks, branches, etc., and in general of all organic material and all the material that is not appropriate for backfilling. The COR will approve the material that will be used for backfilling in advance and the material will come from the excavation itself or other extraction sites.

The backfilling will be done according to the project specifications and according to the lines, levels and gradients described in the architectonic and structural drawings. The Contractor is required to obtain, transport and maintain the necessary material for backfilling, either from the excavation site or from qualified quarries.

Special care will be given by not using the mechanical compactor in areas close to buildings or existing construction inside or outside of the property. If any damage occurs, this shall be repaired and costs assumed by the Contractor.

The refill and/or cover of any excavation that contains lines or pipes installations and other services will not proceed until they have been placed and tested as well as approved and accepted by the COR.

The backfilling for subflooring will be placed and mechanically compacted in beds of 0.20m thick according to the D698-64T specifications of the American Society for testing and Materials (ASTM).

Backfilling with gravel, sand or ground stone for formation of drains or filters shall be consistent with the grain grading specified in the working drawings;

materials will be sieved and washed if required. For filter formation, the materials will be placed in such a way that the higher grade particles remain in contact with the structure and the ones with lesser diameters in contact with the natural terrain, unless otherwise indicated.

C4.2.8 Compacted backfilling with natural soil

Compacted backfilling with natural soil is defined as placing horizontal layers of the existing soil, with a thickness of 20 cm, with the humidity that the material requires to get a mechanical compression to 95% minimum of the density of the

Proctor Standard measure. Each layer shall be evenly compacted on the entire surface by pneumatic rammers or other construction equipment until obtaining the maximum compression possible with the use of these tools. The material to be used in this backfilling shall be free of organic residues and waste. Prior to backfilling, the land shall be free of debris. The COR will approve in advance the material that will be used in the backfilling process. The compaction process shall be done according to the standards of the American Association of State

Highway and Transportation Officials (AASHTO T-130).

If the approved material for this backfilling is not enough to reach the levels specified in the project design, the Contractor shall complete the volume needed, with granular material according to the specification for “Compacted backfilling with granular material.”

The Contractor shall carry out laboratory tests to guarantee the compliance with the aforementioned specifications and the cost of these tests will be assumed by the Contractor.

C4.2.9 Compacted backfilling with granular material

Compacted backfilling with granular material is defined as placing horizontal layers of sub-base to a maximum thickness of 20 cm. Each layer will be compacted evenly on its entire surface by pneumatic rammers or heavy construction equipment until obtaining the maximum compression possible with the use of these tools. Compaction shall be carried out using sheep foot rollers, pneumatic-tried rollers, steel-wheeled rollers, vibratory compactors, or other approved equipment. The thickness of the backfilling shall be in accordance with the structural and architectonic detailed drawings. Prior to backfilling, the land shall be free of debris. The COR will approve in advance the material that will be used in the backfilling process. The compaction process shall be done according to the standards of the American Association of State Highway and

Transportation Officials (AASHTO). Compacting shall be have a 95% of the maximum density (Proctor Test). The material to be used shall be granular selected material according AASHTO 145 (A1, A2, and A3).

C5. CONCRETE

General

The production, transportation and placing of concrete used to build the project must comply with the recommendations of the American Concrete Institute

(ACI), which are found in the “Specifications for Structural Concrete For Building”

ACI 301 Committee report, last revision. For all of the other processes involved with reinforced concrete, all of the recommendations of the ACI 318 “Building

Code Requirements for Reinforced Concrete”, last revision, must be followed.

Compliance with the standards and specifications of the American Society for

Testing and Materials (ASTM), mentioned in this document and related to reinforced concrete, is mandatory.

Properties and characteristics of concrete

C5.2.1 Applicable publications

Concrete building, be it onsite or ready mix, must follow the technical and constructive standards presented in the following publications, in its current versions:

● ACI

● CRSI

● Applicable ASTM standards

C5.2.2 Cement

Cement used in any work execution, must be Portland Type 71-Normal cement, compliant with the ASTM C-150 standard. It must arrive the project´s warehouse in its original packing, without any sign of tears or material hardening. If the COR detects any anomalies, he will be able to request a partial or complete product lot substitution.

Cement must be kept in a fresh place and covered in a way that it isn’t exposed to rain or affected by humidity. The product is allowed to be stowed in 10 cm tall wooden pallets in ten bag stows as maximum.

C5.2.3 Sand (fine aggregate)

The sand used for concrete producing must be river sand, except in special cases. To verify its quality, samples must be approved by the COR, especially when using quarry sand. In any case, sand must have a siliceous-calcareous origin, free from any deleterious substance such as, clay, silt, lignite or alkali. It must be free of any dirt, and kept dry so that its humidity levels are according to the mix design and therefore the volumetric or by weight dose used to make concrete. Sand used for concrete elements shall comply with the ASTM C33 standard, in its current version.

The used sand must have grain sizes within the following limits:

3/8” Sieve --------------------------- Percentage passing: 100.

# 4 Sieve --------------------------- Percentage passing: 95 a 100.

# 8 Sieve --------------------------- Percentage passing: 80 a 100.

#16 Sieve ---------------------------- Percentage passing: 80 a 100.

# 30 Sieve --------------------------- Percentage passing: 25 a 60.

# 50 Sieve --------------------------- Percentage passing: 10 a 30.

# 100 Sieve -------------------------- Percentage passing: 2 a 10.

C5.2.4 Gravel (coarse aggregate)

Coarse aggregate consist of materials which main content is gravel or broken stone. These materials must be clean and free of any substances such as soil, clay, silt and other organic materials which could produce fake adherence in the concrete mix.

The required measures for coarse aggregates used for concrete, are:

● For thin, reinforced concrete elements, less than a fifth of the mold’s lesser dimension and less than three fourths of the space between rebar.

● For elements having, approximately, a 6 cm thickness, the use of aggregates bigger than 25 mm is prohibited.

● For elements such as beams, columns and any reinforced concrete element, aggregate with a diameter less than 38 mm must be used.

● For non-reinforced concrete elements, aggregate with a diameter between

38 mm and 50 mm can be used.

● For massive concrete elements, aggregate with a diameter up to 150 mm can be used, prior to the COR approval.

● Coarse aggregate storage must be done in a way that different sized products don’t mix, for which wooden board enclosures, forming quadrants, with enough height for stocking more material. Each enclosure must have a sign that indicates the diameter of the aggregate. Cone shaped piles are forbidden, and a flat surface must be maintained while in storage, so that any debris can be easily removed and won’t easily mix with the clean aggregate.

C5.2.5 Water

All of the water used in the mixing, curing and mortar production, must be clean, potable water. The water quantity to be used in each concrete pouring, must be according to the specific dosage presented in the following table:

WATER/CEMENT RATIO BY

WEIGHT

PROBABLE COMPRESSIVE STRENGTH

AT 28 DAYS

0.45 350 Kg/cm2

0.53 280 Kg/ cm2

0.62 225 Kg/ cm2

0.71 175 Kg/ cm2

C5.2.6 Additives

The use of any concrete additives, i.e. setting accelerants, retardants, or hardeners, must be done after the COR request or approval. In case that the requested additives aren’t commercially available, any similar products must be submitted for approval with its respective manufacturer’s technical manual. Any approved additive must arrive to the construction site in its original package.

C5.2.7 Hand mixing

Concrete production using any manual methods is not allowed. In especial cases in which, for example, small volumes are required, excessive travel distances or difficult access circumstances are present, the COR can eventually allow, without any responsibility, the use of hand mixed concrete.

C5.2.8 Mechanical concrete mixer

The mechanical mixing of concrete is the only type of process allowed. The COR has the authority to inspect and approve all of the equipment used for mixing concrete. The requisites that need to be met, are:

All of the equipment employed must be in good mechanical and operation conditions. A water weight or water level controller for the mixer is desirable.

The mixer´s barrel size must be according to the concrete volume to be poured.

Concrete mixers with a capacity of less than a cement bag are not allowed to be used on-site.

All of the necessary equipment for any given pouring job to be continuous, free of any interruptions, must be available in the project. The COR can request, according to the volume of any pouring job, the addition of mixers and other equipment.

When placing any concrete, the concrete mixer and any other equipment used during the process must be clean. When the job is finished, or a pause larger than two hours happens, the mixers and any equipment involved must be washed.

All materials must be introduced at the same time in the mixer, so that the mix can be as homogenous as possible

The mixing duration cannot be less than two minutes after pouring all the materials inside the drum.

The time for the concrete to be cast in place, after pouring all the materials in the mixer, cannot be higher than thirty minutes.

C5.2.9 Mixing while in transit

Dry, on-plant dosed, concrete and mixed in transit to the Project can be used.

The truck used must be a drum mixer. Each concrete shipment must complete at least fifty revolutions. The mixing speed will be higher than four drum revolutions per minute and no larger than 225 ft. of drum circumference per minute. The revolutions must be continuous once all of the materials are introduced. The maximum time between concrete deliveries shall not be longer than twenty minutes.

C5.2.10 Sleeves in concrete

The use of sleeves inside reinforced concrete is considered as a non-desired practice. Only special cases, authorized by the COR and indicated in redline drawings, will be allowed with previous presentation of workshop drawings and diagrams. In the case that sleeves are allowed, they shall be located in the central third of the beam’s longitude and the central third of its height. When using pipes smaller than 25 mm in diameter, the separation between each sleeve must be of 25 cm. If the sleeve uses pipe with a diameter between 64 mm to

100 mm, their separation must be at least 50 cm. Additionally, two #3 bars, 50 cm long, frames will be placed, or what the COR indicates.

If the sleeves are placed with one or both of its ends in contact with the ground, plastic covers must be placed at the ends. If the pipes go through a tank’s walls, instead of sleeves a pipe with the same characteristics as the rest of the piping will be placed, with a flange in the walls mid-section.

C5.2.11 Anchors and fittings

Any anchors and fittings necessary to join concrete elements to metal or wood elements are shown in the project’s drawings. The plates or steel sections used to produce them must meet the established criteria in the chapter “Steel

Structure” of this document. Rebar must comply with the requirements established in the steel chapter of this document, having a yield strength equal to fy = 2800 kg/cm2, unless otherwise specified. In any other case, experimental and documental evidence of the element’s weldability must be provided.

The joining element’s size and shape will be indicated in the corresponding drawing, but alternative designs, that facilitates the element’s placement while retaining its structural integrity, can be accepted by the COR. The placement must be done so that formwork removal doesn’t become complicated. During this procedure, the specified opening tolerances must be observed.

C5.2.12 Construction Joints

All construction, vertical or horizontal, joints must be approved by the COR, who will determine where and how it will be built, using the necessary elements (key joints, butt-dowel joint, butt-tie bar joint, etc…). Before the concrete casting, any joint must be moistened and the concrete surface covered with a thick concrete grout.

Contact or isolation joints must be built every time a slab comes in contact with columns, concrete walls, CMU walls or reinforced concrete rigid frames. Isolation joints must be built using expanded polystyrene foam with a 13 mm thickness, or a similar material, adhered with special glue or nails, and the same width of the concrete slab.

C5.2.13 Concrete casting and vibration

The COR shall approve the formwork, molds, temporary structures, and the placement and cover of rebar. He must be notified, five business days in advance, the date and time at which any concrete element will be casted.

All of the necessary equipment for any given pouring job to be continuous, free of any interruptions, must be available in the project. The COR can request, according to the volume of any pouring job, the addition of mixers and other equipment.

Next to the concrete casting place, at least two vibrators in good conditions, with a 65 mm maximum diameter head, will be present. Another smaller vibrator with a 25 mm diameter head, will be available in the project, in the case that thin or densely reinforced concrete elements are needed to be casted.

Casting shall proceed in a continuous manner between the previously approved construction joints, and is only allowed to be interrupted in case that rain can wash the concrete’s surface.

Concrete more than forty-five minutes old is not allowed to be used, nor remixed with water or more cement.

Concrete casting shall be performed with the utmost care, avoiding any separation of the mixed materials, cold joints formation or the creation of layers.

Casting height cannot exceed 2 m from the concrete’s final level.

C5.2.14 Concrete strength

All structural concrete must have the minimum compressive strength, 28 days after being casted, that the drawings specify. For filled CMU (concrete blocks) the minimum compressive strength will be 175 kg/cm2.

C5.2.15 Strength testing

Concrete’s compressive strength will be determined according to ASTM C-39 standard, last revision, in test cylinders with 150 mm Ø x 300 mm dimensions.

The cylinders will be prepared under the COR’s supervision. When taking fresh concrete samples the ASTM C-31 standard, latest revision, will be followed.

Six steel molds will be available on site, taking at least one sample per 20m3 of casted concrete. Each sample will consist, at least, of four test cylinders having the dimensions specified above.

The casting date, casted elements, number and designation of the cylinders, and obtained strength values will be indicated in the project’s logbook.

C5.2.16 Test approval

If compressive strength tests results are not approved, written permission shall be obtained from the COR to procure samples of the rejected concrete section or element and subsequently test them, according to the ASTM C-42 standard.

C5.2.17 Concrete curing

All built reinforced concrete elements shall be appropriately cured. This process must begin once the element’s surface has acquired enough hardness so that its integrity isn’t affected by the force of the water jet. The curing must start four hours after the concrete casting, at the latest.

In extensive concrete elements, with large surface areas, such as walls or slabs, prone to damage caused by the sun or wind, the COR shall indicate the appropriate curing procedure, without this justifying the contractor for charging any additional costs.

All curing process will have a 7 day minimum duration, even if the formwork has not yet been removed.

C5.2.18 Concrete defects reparation

After every concrete casting, any defects indicated by the COR will be repaired.

The defective section will be scarified or cut, forming clean tooth, removing any loose material by using compressed air in the produced cavities. The sections being repaired will be filled with epoxy mortar, following the manufacturer’s instructions. The specific product to be used shall be indicated by the COR. The sand used to help in the reparation will be dried in an oven, so that any moisture is removed.

Formwork

C5.3.1 General

The reinforced concrete casting process must be performed using any COR approved formwork, using the specified measures for every element according to the drawings.

Formwork must be rigid and its reinforcing temporary structures must be designed and built with enough strength to resist: its own weight, the formwork’s weight, the concrete’s weight and any imposed load during the construction process, so that the formwork and temporary structures won’t suffer any distortions which could affect the final product. The materials used must be in good conditions, and the surfaces that will be in contact with the concrete must be free of any leftover concrete from previous castings, nails, or any other object not part of the specified concrete mix, such as hooks, black steel wire, staples, etc….

To compensate any deformations and distortions in elements with excessive weight, a precamber can be given to the formwork or temporary structures, given the COR’s approval.

To facilitate formwork removal, a release agent can be used after being approved by the COR. The aim of any formwork job is to obtain the final finish once it is released, except when the drawings indicate other finish type. Before any casting job, the formworks must be submitted for the COR’s approval, who will accept, reject or request changes to the formwork.

C5.3.2 Wood Formwork

Formwork built using wood need special care due to its short lifespan. Because of this reason, this type of formwork shall be used a maximum of three times.

In special cases reuses can be allowed, but only if the following conditions are met:

● Wood used in formwork will be sufficiently dry and of top quality, so that no excessive deformations will occur during the casting and curing process.

● Wooden plank thickness shall not be less than 25 mm.

● Planks must be reinforced with wooden beams having dimensions of 2.5 cm x 7.5 cm at 60 cm, to avoid deformations.

● The formwork’s surface in contact with the concrete shall present a smooth, brushed, crack and defect-free surface, so that it won interfere with the concrete casting process.

● Any rectangular shaped wood element used for formwork reinforcing must have a minimum thickness of 5 cm in any side, and it must be clear of any deformation or twists that may compromise the formwork.

● Wood employed as formwork can be treated with a COR approved formwork releasing agent.

● A wide variety of wood types can be used as formwork, such as: Pilón, Gallinazo, Amarillón, Lagarto and others.

C5.3.3 Plywood formwork

Formwork built using plywood must be used when excessive surface areas are encountered in a casting job, and in those cases that, due to design requirements, they must remain exposed or the COR has requested so. Plywood used as formwork must be at least of second hand quality, which shall be indicated with an appropriate manufacturer’s certified seal.

The formwork side which faces concrete, while working with plywood, will be in good conditions, which means that no deformations, splintering or any other defect that can compromise the final product shall be allowed.

The minimum allowed thickness for plywood used as formwork shall be of 12 mm, with 40 cm x 40 cm traverse wooden beams, with a minimum 5 cm x 5 cm section.

C5.3.4 Metal formwork

Formwork built using metal are considered as a desirable system for use in reinforced concrete casting (especially those systems which are widely recognized), as long as all materials are in good shape.

Molds used in the mentioned system shall be free of any deformations, rust, holes or welding burr. Additionally, any temporary structure used to support formwork can be metal or wooden, or a combination of both. The number of allowed uses are dictated by the formwork condition and quality prior to each use, with the COR’s approval.

C5.3.5 Other materials

The COR shall indicate or authorize the use of special materials for formwork in those cases that design and constructive drawings require it, or when reinforced concrete is built in places where formwork removal is too complicated and/or expensive. Particle boards will not be accepted for use as formwork or support.

C5.3.6 Formwork construction

All constructed formwork must follow a process such that the next phases are completed:

Formwork design and shop drawings elaboration.

Shop drawings approval by the COR.

Material selection.

Built up, assembly and reinforcement.

Constructed formwork COR approval.

Formwork releasing after COR approval.

Work area cleaning, formwork cleaning and equipment storage.

The COR shall approve or request partial or total substitution of formwork which he considers that don’t meet the required criteria for work execution. The COR will be able to request, at any time, the detailed formwork drawings and calculation report.

C5.3.7 Non-exposed concrete formwork

Formwork used for…