J-1-1_Statement_of_Work_(A0001)_(CLEAN).pdf

ATTACHMENT J-1-1

SECTION C – STATEMENT OF WORK

REMODELING AND EXTENSION OF THE INSPECTION

SITE FOR THE CANNINE UNIT OF THE OIJ

COSTA RICA

GENERAL DESCRIPTION

The Embassy of the United States of America, through the International Narcotics and Law Enforcement (INL) Affairs Office, in cooperation with the Organization of the Judicial Investigation of Costa Rican (OIJ) is heading an infrastructure improvement project for the Canine Unit of the OIJ.

The overall intent of the contractual effort for this project is to make a renovation of an existing building, which consist in remodel and extend the area in order to convert the building in an Inspection Site. The project shall be performed according to the basic designs that had been performed by the INL technical advisor. The existing building is located at Ciudad Judicial San Joaquin, Flores district, Heredia province, Costa Rica (from San Joaquin’s cemetery 400m to the north east ).

The project shall be conducted in accordance with the plans and specifications detailed in this document. The Contractor shall perform the following work:

C.1 Specific Task

C.1.1 Preliminary Work

Preliminary work includes the implementation of temporary facilities for the workers according to the specifications detailed in C.3.1.

Also preliminary work includes the dismounting of the existing roof and the dismounting of the existing metallic wall panels that are no longer needed in order to accomplish with the new architectural distribution.

These materials shall be delivered to the OIJ’s Canine Unit in writing and with a detailed inventory. The actual conditions of the building is shown at drawing AA-01; nevertheless the Contractor is responsible of verifying the existing conditions of the building and considers it in the renovation of the building.

Regarding the metallic structure of the roof, the contractor shall also dismount it, and the materials can be reused for the new design. Before using it the contractor shall clean and repair any damage due of the corrosion as it is described at C.1.2.

The preliminary work shall also include a technical revision of the designs and the technical advice in order to nationalize the designs and accomplish with all the local requirements that the host country demands for construction approvals. Therefore the contractor shall provide all the qualified technical staff that will be responsible of all the designs, and will develop all the drawings according the local regulations based on the designs, drawings and specifications stated in this document. The Contractor shall ensure that the designs are in accordance with the relevant specifications and requirements:

Design of the Main Structure and Roof (see Section C.1.2) Design of the Walls and Fascia (see Section C.1.3) Design of the Hydraulic and Sanitary Systems (see Section C1.7) Design of the Electrical System (see Section C.1.8) Design of Special Systems (see Section C.1.9)

C.1.2 Design and Build of the Main Structure and Roof

In order to implement the Inspection Site, the contractor shall design and build a main structure that shall be based on the architectural drawings AD-01, AD-02, AD-03, AD-04 and AD-05. This main structure has two areas; the first one is the existing area in which the contractor has to remodel the structure of the roof according to the architectural design. The second area is an extension in which the Contractor shall perform a new construction including the respective concrete foundations. The structural designs shall be performed by the Contractor and shall include the respective soil survey in order to guaranty the stability of the building.

The main structure shall also include the respective retaining walls for which the contractor shall design and build reinforced concrete walls that shall be in accordance to the respective soil survey recommendations. The structure shall be designed and build with metallic shapes that will be painted minimum with two layers of anti-rust paint and two layers of enamel. Also the metallic shapes of the existing building can be reused; in this case the contractor shall clean and repair any damage due of the corrosion previous the use of it. It is needed to clarify that the Contractor is allowed to design metallic or concrete columns for the extension, but any structure system shall meet all the local regulations of the College of Engineers and Architects of Costa Rica (CFIA) and the following codes and regulations. In case of conflict, the criteria that will be safer for the users will prevail.

Concrete Elements: CFIA Regulations, American Concrete Institute (ACI), Portland Cement Association Pre-stressed Concrete Institute.

Metallic Elements: CFIA Regulations, American Institute of Steel Construction, American Iron and Steel Institute, Steel Joist Institute, American Welding Society (AWS).

The roof for this building shall be constructed with a new thermal and acoustic metallic panels according to the specification detailed in this document. The roof shall be supported over metallic beams that are part of the main structure.

C.1.3 Construction of Walls and Fascia

In order to accomplish with the architectural design (AD-01), the contractor shall build the walls using concrete masonry units (CMU) and metallic fascia boards that shall meet the respective specifications. The walls finishing shall be according to the schedule detailed in drawings AD-04 and to the facades detailed in drawings AD-02 and AD-03. Also the contractor shall design and build metallic flashings and sealed systems in order to cover any type of hole to guarantee that the natural light does not enter to the inspection area 101.

C.1.4 Floors, Windows, Doors and Finishing

The floor for the extension area shall be built by the contractor with reinforced concrete in accordance with floor detail #1 (see drawing AD-04), while at the remodeling area the floor shall be repaired and a new concrete layer of 5cm (210kg/cm2) shall be constructed over it by using concrete additives for an appropriate joint with the old concrete. The finishing shall be according to the schedule detailed in drawing AD-04.

The contractor shall provide and install all the doors and windows required for the building according to the respective specifications and to the architectural drawings AD-01, AD-02, AD-03, AD-04 and AD-05.

For areas 102, 103, 104, 105, 107 and 108 the contractor shall provide and install a ceiling Armstrong type which shall be according to the specification detailed in this document.

Timber mop boards shall be provided and installed by the contractor for areas 104, 105, 106, 107, 112 and 113 and shall meet the respective specification.

For the laboratory (108) and for the monitoring room (107) the Contractor shall build countertops constructed with natural granite according to the respective specifications.

C.1.5 Construction of Pedestrian Access

As it is shown in drawing AD-01 the contractor shall design and build a pedestrian access that includes a ramp and sidewalks constructed with reinforced concrete according to specifications and the construction details of the architectural drawings. All the backfilling required for the ramp shall be done with granular compacted material according to the respective specification. Also the pedestrian access includes stainless steel hand rails for the ramp according to drawings AD-01 and AD-02.

C.1.6 Construction of Vehicular Platform and Ramp

In order to have a vehicular access to the inspection site, the Contractor shall build a concrete platform and a ramp according to drawing AD-01. The platform and ramp shall be constructed with 210kg/cm2 concrete and reinforcement according to the floor detail #2 shown in drawing AD-05. The finishing of these floors shall be smooth, and shall have constructive expansion joints and according to the respective specification.

The vehicular access shall include a sliding metallic door (SD01) manufactured with galvanized mesh according to the respective specification.

C.1.7 Hydraulic and Sanitary Systems

The contractor shall design and build the hydraulic and Sanitary system that includes the potable water system, the sewer system and the sanitary devices which includes one toilet, two wash basins, two electric showers, one safety shower with eye wash and one stainless steel sink for the laboratory.

Construction of a potable water system

The contractor shall design and build the water system in order to provide the service for the bathroom, showers, laboratory and for the fire hose cabinets, following the basic specifications stated in this document.

The showers at the dressing areas shall include a hot water system that includes an electric tankless water heater. The water system shall meet the basic requirements detailed in drawings WS-01 and SS-02. 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 comes from the public service that provides water to the existing facilities. The contractor shall connect the new water pipe lines to any existing water line inside the facilities of the canine unit, if the work implies to demolish, damage, dismount any type of facilities, the contractor at the end of this work shall repair and fix the existing facilities leaving it as it was before the intervention.

The system shall follow the local regulations and the regulations of the American Water Works Association (AWWA), and the National Standard Plumbing Code (NSPC).

Construction of the Sewer System

Also the Contractor shall design and build the sewage system for the bathroom, showers, laboratory, gutters and for the drainage of the air-conditioning system and shall provide, place, connect and satisfactorily test the pipes, revision points, and other devices of the entire sewer system. Requirements include a connection to the public sewage system to provide appropriate drainage of wastewater. The sewer system shall meet the basic requirements detailed in drawings SS-01, SS-02 and SS-03.

C.1.8 Construction of the Electric System

The contractor shall design and build the electric system to meet the basic requirements identified in drawings ES-1 and ES-2 and according to the Local Electric Code. This must be developed and certified by an accredited Electric Engineer.

Also the Contractor shall include the electric connections required to install the fire protection system, security system, water heater and the air conditioning and ventilation system.

The electric supply for the building shall be from the electric line that is located in front of the existing building.

The final connection from the electric supply to the main electric boards shall be designed and build by the Contractor in order to have the electric service for the basic requirements.

The electric requirements include a master switch in order to turn on and off all the lights that are in or around the inspection area (101) due that the technical investigation process requires a complete darkness to develop it.

C.1.9 Construction of Special Systems

Construction of the Fire Protection System:

The fire protection system includes a fire alarm system with smoke detectors, and fire hose cabinets that should be according to drawing ES-2. Due that the inspection area needs special treatment for the investigation process, the emergency lights located at the inspection area (101) shall be installed no more than 2.00m in high and shall have a control switch that can easily be disconnected in order that it does not work during the investigation process. Also the alarm shall have movement detectors to control the access of areas 101, 104, 107, 108, 110, 112 and 113.

The contractor shall design and build this system according to the mentioned drawings and specifications.

Air Conditioning and Ventilation System:

The Contractor shall design and build the air conditioning and ventilation system according to the basic requirements detailed in drawing ES-2. The equipment for these systems shall be provided and installed by the contractor. All the equipment shall be from well-known brand from United States that can be easily obtained in Costa Rica for maintenance purposes. The contractor shall follow all the recommendations from the manufacturers.

The air-conditioning will be provided for the office areas # 104, 107 and 108. The design and build will be done with split systems that will have the cabinets located according to the basic drawing S-1, while the condenser units will be located according to drawing ES-02 in the new walls of the extension area. Regarding the ventilation system, the contractor shall design an appropriate system in order to extract the odors from the bathroom (102). For areas 109, 111, 112 and 113 the contractor shall provide and install one ceiling fan for each area, while for the inspection area (101) the contractor shall install 6 industrial fans.

Security System:

The Contractor shall design a CCTV system that shall include one server with two 40” monitors located at area 107, 4 cameras located at area 101, 2 cameras located at area 104 and 4 cameras located at the exterior.

According to the design prepared by the Contractor INL will provide and connect the equipment, while the Contractor shall provide and build the conduit system and the electric points in order to connect the CCTV system. The connection constructed by the Contractor shall be with cable cat.10, which shall be hidden in walls, ceilings, and floors using PVC conduit pipes

Data and Telephone System:

The watching room 104, the monitoring room 107 and the laboratory 108 shall have outlets for telephone, this system will be designed and build by the contractor in order to connect the new outlets to existing telephone system that is located at the existing building. It is needed to clarify that all the equipment for this systems are not part of the contract, these equipment are: telephones, computers, servers, and telephone central system. The Contractor has to provide and install all the cables, conduit system and outlets so the Canine unit can connect their equipment to the new infrastructure.

C.2 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.

C.2.1 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.

C.2.2 TRIALS AND TESTS

Materials, permanent equipment, its accessories and other elements destined to the work, shall be subject to trials and tests necessary to verify their compliance with specifications, properties and characteristics, in accordance with permitted 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, 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.

C.2.3 WORK EXECUTION

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

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, either from the COR, in order to continue with subsequent stages of construction. Before receiving approval to continue through various stages of work, 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. For this purpose the contractor shall consider that INL will require at least 3 months in order to provide the equipment that INL is being committed to deliver. This period is considered from the date that Contractor provides the respective designs (drawings and specifications). If for some reason INL does not deliver these equipment at the programed date and it will cause a project’s delay, the government will approve a performance extension, but it will not approve any cost adjustment.

C.2.4 COST OF THE PROJECT

The Contractor should 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.

C.3 Task Specifications

C.3.1 PRELIMINARY WORK

C.3.1.1 LAYING OUT AND LEVELING

Prior to initiating construction, the Contractor and COR will define the outline of the components of the project in accordance with the project drawings and, if necessary, the construction levels to be achieved will be appointed.

Additionally, signals (B. M.) shall be placed on the main points to confirm location and levels of work. The signals shall be with paint at strategic points at the existing walls.

Before beginning the remodeling, the Contractor shall verify all data, as shown in the drawings, and correct them in case there are any divergences between the real dimensions of the building and the data of the drawings, in accordance with the COR.

The construction axes and levels shall be marked in the building in a safe manner. The marks should be the most precise, clear, safe and stable for the most important axes and elements.

To comply with these requirements, the Contractor shall provide an expert topographer, supported by precision equipment such as: total station, levels, measuring tape, etc. as required for the placement of milestones and layouts of the remodeling project.

C.3.1.2 WARNING SIGNALS:

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.

C.3.1.3 TEMPORARY STRUCTURES: OFFICES, SANITARY FACILITIES & WAREHOUSES

Temporary structures will be implemented in the existing facilities for the Contractor’s personnel, the COR, the Government Technical Advisor (GTA) as well as for the ICD’s workers. It is the Contractor’s responsibility to implement offices, warehouses, provisional bathrooms and the guardhouses required for their own use. These areas can be implemented in the existing building that is going to be demolished.

The Contractor will implement provisional offices, sanitary facilities for the personnel, and a guardhouse with a temporary connection to a potable water and sewage system prior to commencing construction. One sanitary facility shall be implemented for every 10 workers, and one for the technical staff, the COR and the GTA. The Contractor will provide a 9 square meters office for the exclusive use of the COR, the GTA or his authorized assistants. The Contractor will be responsible for cleaning and maintaining these structures.

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

C.3.2 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, channels, piping, and all elements indicated in the project drawings.

C.3.2.1 LEVELING AND CLEARING OF LAND

This section refers to land modifications required for the execution of building construction in accordance with the project drawings.

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.

C.3.2.2 SLOPE CONFIGURATION

This portion of the contract will be carried out by hand. It consists of giving the slope a slant recommended by the soil analysis to avoid sliding of material or soil. The purpose is also to provide appropriate precipitation drainage, including very heavy rainfall.

Once excavation is finished and approved, resulting levels shall be verified to establish the need for complementary manual work for slope configuration. Location of final slants and levels shall be done to reach finished surfaces, in accordance with the final designs provided by the Contractor. Material which is wobbly, cracked, or in danger of sliding shall be removed by the Contractor.

The intersection area of the excavated slope and the natural land surface will be rounded off if required by the project. This activity, as well as material removal, is part of the slope configuration portion of the contract.

Disposal of excavation material will be done in places allowed by the beneficiary.

C.3.2.3 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 to be performed in the places where specific concrete, exterior works are to 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 so that the base soil is loosened or removed. If this happens, it will be considered as an “over excavation” that should be corrected by the contractor according to the project 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 such a way as to guarantee the stability of those buildings without causing any damage.

Excavation shall be protected against rain, landslides and other excavation. The Contractor shall protect the personnel executing the excavation 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.

The standards for the provisional shoring in excavations are the following:

a.- When assemblages and props are used, these are placed at intervals no greater than 2.50 meters, measuring the timber lengthwise, and should penetrate the land enough to withstand the push of the walls in the excavation.

b.- Metallic cribbing shall be used for excavations greater than 5.00 meters deep or when the lateral push on the excavation walls is great.

c.- Whenever the conditions of the land demand so or when the structural drawings states, the excavation walls will be protected with stakes or projected concrete. This will be subsequently refilled according to the requirements established for the filling process.

For piping placement in excavation, the filling will be laid as a first step to cover a height of at least 20 centimeters 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.

C.3.2.4 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 compressor. The compression 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 granular selected 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.

C.3.2.5 EXCAVATION IN CONGLOMERATE STRATUMS AND ROCK

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 a 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 pipes lines) 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.

C.3.2.6 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. Excavating during the rainy season shall be prohibited.

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.

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.

Excavation is forbidden during the rainy season. 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.

C.3.2.7 EXCAVATION FOR FOUNDATIONS

This section refers to the depth of the excavation needed for foundations that will be lower than that marked for cleaning and leveling, down to the depth established by the structural drawings or by recommendation of COR.

Excavation will be done in a fashion to satisfactorily build the structures. The excavation sides will be totally vertical and the bottom will be clean, free of waste, and correctly leveled.

In no case will machine excavation be performed to a depth so that the soil of the bottom is loosened or removed. The final material to be excavated must be removed by pickax and shovel to a depth of 50 centimeters, also known as “conforming the plinth or ditch bottom”.

If landslides or collapses due to the depth of excavations or inconsistency of soil happen, shoring shall be built to prevent further damages or accidents.

Ditches shall remain clean and no work will be executed in them if waste, loose dirt, water, etc. are found.

After casting the foundation and pouring the foundation, the gap caused by excavation shall be filled and compressed with the extracted soil until reaching the initial level. This work shall meet the specifications detailed for “compacted backfilling with natural soil”. Leftover material shall be removed or placed as filling if acceptable by COR.

The Contractor shall take all necessary precautions to prevent water from entering excavation sites awaiting concrete pours. However, if soil deterioration is caused by unforeseen circumstances, the Contractor will perform necessary studies and analyses of the soil to deepen excavation.

C.3.2.8 REMOVAL OF WASTE 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.

C.3.2. 9 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 D698-64Tspecifications 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.

The backfilling of rock placement shall be made with fragments of healthy, dense, and exposure-resistant rocks, with angle formation satisfactory to COR. The minimal size of the stones shall be 20 centimeters, and the maximum determined by the project, always protecting the structure.

C.3.2.9.1 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 compression 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.

C.3.2.9.2 COMPACTED BACKFILLING WITH GRANULAR MATERIAL

Compacted backfilling with granular material is defined as placing horizontal layers of sub-base to a 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 sheepsfoot 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 compression 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, A3).

C.3.3 CONCRETE STRUCTURES

C.3.3.1 MATERIALS FOR CONCRETE

C.3.3.1.1 CEMENT

Cement is any powder-like material that mixed with a liquid, forms a binding paste capable of hardening, in time, both under water as well as in free air and which serves to join solid bodies. It must comply with the ASTM standards, specification C 150.

The Contractor shall provide adequate facilities for the storage and protection of the cement against humidity.

Cement that for any reason is partially dried or has clods is unacceptable. The Contractor will not use rejected cement or previously used bags of cement.

Portland Standard cement of national production will be used and should comply with ASTM specifications and be accepted by the corresponding entities. The use of foreign cements is acceptable in case national cement is unavailable, as long as these foreign cements comply with the same basic requirements. All cement shall comply with the regulation RTCR 383:2004 (“Reglamento Técnico de Costa Rica”). The use of different brands of cements is not recommended at all when building one single structure or foundation.

The manufacturer might decide to add additives during the cement manufacturing process, which is acceptable if those materials, in the amounts to be used, meet the requirements of ASTM standards.

The cement must be stored in a completely dry and ventilated place, under cover, and placed on wood pallets.

No more than 14 bags of cement should be placed on top of each other and the cement should not be stored for long periods of time.

If Portland cement has been stored in bulk for over 6 months or has been stored in bags for over 3 months, the cement should be sampled, tested and must meet the appropriate requirements, before being used.

Cement shall meet the tests listed in the previous paragraph, and correspond to ASTM and AASHTO standards:

TYPE OF TEST

Chemical analysis Grain fineness Setting time Normal consistency Resistance to compression Resistance to flexion Resistance to pulling forces

If the test results do not fulfill specified requirements, the cement will be rejected.

If there are several types of cement, these should be stored separately and correctly identified so that they are not mixed.

C.3.3.1.2 GRAVEL STONE AGGREGATES

Gravel stone aggregates for concrete will be made up of gravel, crushed rocks, or a combination of these, and shall meet the requirements of the American Concrete Institute ACI, AASHTO and ASTM standards.

Concrete will use mechanically ground rocks, from andesitic sources, preferably made out of blue rocks.

Gravel stones used for the manufacturing of any type of concrete shall be the product of mechanical grinding;

the use of natural material extracted from a quarry is not allowed. This material shall preferably be blue stone and shall have passed through a 4 cm sieve, as specified in the ASTM standard.

The Contractor shall assure availability on the work site of the required quantity of gravel stone that will be used for mixing concrete, fills, filters, transition zones, drains, etc.

The Contractor shall use gravel without impurities, organic matter and other harmful elements. It shall be thoroughly washed before use. Tile-shaped or long- shaped gravel is not allowed.

The thick aggregate that shall be used for concrete elaboration will consist of hard rock fragments with a diameter not less than 5 millimeters, dense and long-lasting, free of objectionable quantities of dust, soil, slates, alkalis, organic material, vegetable soil, mica and other harmful substances.

Round-shaped gravel that has been manually crushed or gravel from natural quarries, as long as it has a cubic or pyramidal shape, may be used. Gravel with over 15% of flat or long-shaped rocks will not be used.

The production and storage of gravel shall be done by dividing the gravel into three separate groups according to the maximum nominal size of the gravel and the following requirements:

SIEVE PERCENTAGE OF MASS PASSING SAUARE MESH SIEVES

(square openings) No.4 to 3/4"(19 mm) 3/4" to 11/2"(38mm) 11/2 to 2" (76mm)

3" (76 mm) 90-100 2" (50 mm) 100 20- 55 11/2" (38 mm) 90-100 0- 10 1" (25 mm) 100 20- 45 0- 5 3/4(19mm) 90-100 0- 10 3/8(10mm) 30- 55 0- 5 No. 4(4.8mm) 0- 5

All components added to Portland cement concrete shall meet the requirements regarding particle size standards according to ASTM C136-06 and to the regulations of INTECO (Instituto de Normas Técnicas de Costa Rica).

The ASTM standard requires particle sizing tests to verify their sizes. This will also be confirmed by the Contractor.

The specific gravity of particles shall be determined according to the testing method specified by the ASTM standard.

The following are the maximum allowable percentages (expressed as percentages of the sample weight) of foreign substances and determining factors of added components.

COARSELY-GRAINED COMPONENTS % OF THE TOTAL WEIGHT

Firmness, sodium sulphate, losses after five cycles: 12.00 Abrasion – Los Angeles test (losses): 35.00 Material that passes through sieve number 200: 0.50 Clay: 0.25 Coal and lignite: 0.25 Soft or lightweight particles: 2.00 Other substances: 1.00

The amount of harmful substances in gravel stone shall not exceed the limits specified by the ASTM standard for this component.

The use of premixed concrete produced by companies that have certificates proving the use of high-quality materials is recommended. Specifically, the company must support its decision to use certain materials based on their resistance, which cannot be lower than the one specified in the structural design.

C.3.3.1.3 FINE-GRAINED SAND

Fine-grained sand for concrete should be comprised of natural sand, sand from grinding processes (gravel), or a combination of both.

The sand should be clean, siliceous (quartz or granite sand), from mines or from other inert materials with similar characteristics. The sand should be made up of hard, angular and rough grains, which should be strong and free from soft particles, organic material, shale or slate. Clayish, soft or disintegrating sands must not be used. Likewise, finely-grained sand with a humidity of over 8% must not be used.

The requirements regarding particle sizing should meet the INTECO and ASTM standard, i.e. arid elements for concrete. Requirements: The fineness module should be less than 2.4 and greater than 3.1. After the particle size has been established, the fineness of the sand module should remain stable, with variations of at most ± 0.2.

Otherwise, the COR may decide that other combinations must be produced. If there are no satisfactory results, this material must be rejected.

The material shall meet the following tests:

The ASTM C136-06 standard specifies the particle sizing tests to be undertaken to verify their sizes.

The specific gravity of sand particles will be determined according to the testing method specified by the ASTM standard.

The weight per unit of sand particles will be determined according to the testing method specified by the ASTM standards for concrete..

The fine-grained arid component must not contain harmful or organic matter. To verify this, the testing method specified by the ASTM standard shall be used. If it is darker than the standard, it must be rejected.

Fine-grained sand that was rejected due to organic impurities can still be used if the discoloring is mainly caused by small amounts of coal, lignite or similar discrete particles. It may also be accepted if, after running tests to determine the effect of organic impurities on the resistance of concrete, the relative resistance, after a seven-day period, according to the ASTM standard, is not lower than 95%.

Fine-grained sand to be used in concrete that will be exposed to water, to prolonged exposure to environmental humidity, or contact with soil humidity should not have materials that might react adversely to the alkali of cement and whose amounts are such that an excessive expansion of concrete might take place. If these materials are present in harmful amounts, fine-grain sand can be used, provided that the cement will have less than 0.6% alkali estimated based on the amount of sodium oxide.

Fine-grain sand submitted to 5 immersive and drying cycles for the test to measure the resistance to disintegration (the ASTM standard) must have a mass loss of less than 10% if sodium sulphate is used and less than 15% if magnesium sulphate is used. Finely-grained sand that does not meet these standards may be used provided that concrete with similar features, made from similar sand from the same source, has produced satisfactory results when exposed to similar weather conditions to the ones to which the concrete with those characteristics will be exposed.

All fine-grain sand used for tests shall meet the sampling requirements established by the ASTM standard. The amount of harmful substances in fine-grain sand shall not exceed the limits specified by the ASTM standard.

The following are the maximum allowable percentages (expressed as percentages of the sample weight) of foreign substances and determining factors of added components.

FINELY GRAINED SAND % OF THE TOTAL WEIGHT

Material that passes through sieve number 200 3.00 Clays and disintegrating particles 0.50 Coal and lignite 0.25 Other harmful substances 2.00 Maximum allowable total 4.00

The amount of harmful substances in fine-grained sand shall not exceed the limits specified by norms ASTM standard and INTECO (Instituto de Normas Técnicas de Costa Rica) for fine-grained sand.

C.3.3.1.4 LARGE STONES FOR CYCLOPEAN CONCRETE (RIP-RAP CONCRETE)

The large stone for cyclopean concrete shall come from quarries or collection banks that must be clean, granitoid or sandstone. Stones of between 10cm to 25cm in diameter shall be used for this type of concrete. The stone shall not exceed more than 50% of the concrete component. The stone will be solid, resistant and long-lasting, free of organic matter or clay residues. It will be homogeneous, with uniform color and will be free of cracking or crevices (clear sound to hammering), or other flaws that would reduce its strength.

Any weathered stone (affected by meteoric phenomena) must be rejected. It must have a density equal to or greater than 12% on durability assays.

The size of the stones shall not surpass 25% of the smallest dimension on the structure to be built. It is unacceptable to indicate that humidity reduces the strength, and for that reason porous stone assays shall be done by saturation and without localized efflorescences.

The COR has the right to demand from the Constructor the results of tests and assays used to verify the good condition and quality of the aggregate, taking into consideration the norms specified by ASTM and INTECO for this particular case:

Coarse arid materials for concrete. Determines the abrasion value of the coarse arid material for particles greater than 19 mm, using the angel’s machine.

Arid materials for concrete. Determines strength to disintegration.

Transportation will be in bulk and precautionary measures will be taken so that during loading and unloading deterioration is not caused by touching one against the other. Covered storage is not necessary, but the Contractor must insure that the material will not become saturated with dust and other material that can lower its strength.

C.3.3.1.5 TYPES OF CONCRETE

This section consists of all the necessary materials, equipment and labor to make plain concrete.

Concrete is the hardened product resulting from the mix of the Portland cement, water and stony aggregates in adequate proportions. It can contain additives to provide it with specific or special properties.

Cyclopean Concrete (Rip-rap):

Cyclopean concrete shall be constructed with a mixture of a 60% plain concrete and 40% large stones (variable size between 10 and 25 centimeters). The plain concrete to be used in this job shall have a minimum resistance of 180 kg/cm² on the 28th day and the materials should be saturated before creating the mixture. Stony materials will comply with the ASTM standard and dosage will be according to concrete design.

In the first step, the contractor shall apply a plain concrete layer of 15 centimeter depth and subsequently a layer of stone shall be placed manually on top. The spaces between the stones will not be less than 5 centimeters in any of the rows and from structure edges. The next step is to place another layer of plain concrete and the same procedure is followed until the desired height is reached.

The dosage varies in accordance with the structure needs described in the respective drawings.

Plain Concrete:

Plain concrete results from mixing coarse, arid materials of up to 5 cm. in diameter (nominal) and fine, arid materials joined by a paste of water and cement (see specification for “gravel stone aggregate” and “fine-grained sand”).

To obtain good, uniform, strong, long-lasting and cheap concrete, the following items should be closely monitored:

Material quality Dosage of components Management, placing and concrete setting

The proportion of water and cement must be tested for appropriate dosage and should include the following data points:

Degree of humidity of aggregates Climate of the work area Use of additives Conditions for concrete exposure; and Thickness and type of planking

The dosage of plain concrete varies in accordance with the type of work that it’s going to be used on:

DOSIFICACION STRENGHT USE

Kg/cm² 1 : 3 : 6 180 Concrete thick walls of larger thickness, pavements, first concrete layers, floors and anchors for pipes.

1 : 2 : 4 210 Non-voluminous walls and jobs of reinforced concrete in…