DRAFT Description of Requirement for a

Three-Bay High Performance Magazine (HPM)

REQUIREMENT: The U.S. Army Engineer Research and Development Center (ERDC), Geotechnical and Structures

Laboratory (GSL), has a need for the procurement of materials and the on-site fabrication and assembly of one (1) complete, three-bay, monolithic High-Performance Magazine (HPM) reinforced concrete test structure. All work shall be performed in strict accordance with the specifications listed below.

1.0 DESCRIPTION OF STRUCTURE

1.1 General Overview & Configuration

The project requires the on-site, cast-in-place construction of a monolithic, three-bay HPM structure. The final deliverable will be a single, continuous test structure composed of three identical, interconnected bays. The test structure is for experimental purposes only and in the course of testing the structure will be completely destroyed and the site will be retrograded. The vendor shall mirror and repeat the structural details, reinforcement configurations, wall cavities, and dimensions of the single-bay design detailed below to assemble the three bays.

Note that the structural descriptions provided herein are general descriptions for informational and market research purposes only; complete, detailed engineering drawings and specifications will be provided when the project is formally issued for solicitation and bid.

1.2 Overall Dimensions (Per Bay)

o Approximate Footprint: The primary structure of a single bay is approximately 48 feet long by 43 feet wide.

o Approximate Height: The structure stands approximately 15 feet from the finished grade to the top of the roof parapet.

o Layout: Each bay consists of internal "storage cells" and a "transport aisle," formed by a network of thick, reinforced concrete walls.

1.3 Structural Component Details

o Foundation and Floor Slab: The structure is built on a thick, reinforced concrete slab-on-grade foundation.

The slab is approximately 20 inches thick and is heavily reinforced with two mats (top and bottom) of #8 reinforcing bars at 6-inch spacing in both directions. The vertical layers of reinforcement are connected by #4 stirrups at 6-inch spacing. All flexural reinforcing bars must be continuous without splices o Walls and Reinforcement Congestion: The walls form a complex, cellular system creating interior voids that will be filled with structural sand.

o Thickness and Reinforcement: Most walls are approximately 22 inches thick. They are heavily reinforced with multiple layers of horizontal and vertical #8 bars, typically spaced at 12 inches on center.

o Paired (Doubled) Rebar: In many locations, the design specifies paired horizontal reinforcing bars, where two #8 bars are bundled together. This significantly increases steel density and congestion within the formwork. Reinforcement is also doubled around all door perimeters.

o Stirrups and Ties: The multiple layers of wall reinforcement are tied together with #4 stirrups at

6-inch spacing. Wall-to-wall and wall-to-slab intersections are further reinforced with #4 tie bars at 6-inch spacing.

o Continuous Bars: All primary reinforcement is required to be continuous, full-length bars without any mechanical or lap splices.

o Roof Slab and Parapet: The roof is a 30-inch-thick reinforced concrete slab.

o Reinforcement: The roof is heavily reinforced with two mats (top and bottom) of #8 reinforcing bars at 6-inch spacing in both directions. The mats are connected by #4 stirrups at 6-inch spacing.

All reinforcing bars must be continuous.

o Parapet: A concrete parapet, approximately 3 feet high and 0.5 feet thick, is integrated monolithically with the roof slab.

o Retaining Walls and Blast Doors: Concrete retaining walls are integrated into the foundation to support an exterior earth berm on one side. Three reinforced concrete blast doors (approx. 11 ft. wide x 8 ft. tall) must be fabricated and installed for each bay.

2.0 MATERIAL AND FABRICATION SPECIFICATIONS

2.1 Concrete:

o 2.1.1 Concrete shall be a Self-Consolidating Concrete (SCC) mix with a specified minimum compressive strength of 10,000 PSI at 28 days per ASTM C39.

o 2.1.2 A detailed concrete mix design must be submitted to the Government Technical Point of Contact

(TPOC) for review and approval prior to any concrete placement.

o 2.1.3 All ready-mixed concrete shall conform to the general requirements of ASTM C94.

2.2 Reinforcing Steel:

o 2.2.1 All reinforcing bars shall be deformed type conforming to ASTM A615, Grade 60.

o 2.2.2 Splicing of reinforcement is not permitted. All reinforcement must be provided as continuous bars.

Any deviation requires prior written approval from the TPOC.

o 2.2.3 All reinforcing bar bends shall be made mechanically.

2.3 Structural Sand Fill:

o 2.3.1 Dry sand shall be procured and installed into clean and verifiably dry hollow wall cavities. The vendor is responsible for protecting the sand from moisture during storage on-site.

o 2.3.2 The sand shall be installed to achieve a desired in-place density of 100 PCF.

3.0 ON-SITE ASSEMBLY & PROCESS REQUIREMENTS

3.1 Formwork:

o 3.1.1 The vendor is responsible for the design, fabrication, on-site erection, and subsequent removal of all temporary formwork systems. The formwork design must be engineered to withstand the high fluid pressure exerted by the 10,000 PSI SCC mix, which may exceed standard concrete pressures.

o 3.1.2 A formwork plan, including calculations for hydrostatic pressure and details of bracing, must be submitted to the TPOC for review prior to formwork erection.

3.2 Assembly Process: The HPM structure shall be fabricated in-situ (cast-in-place) at its final location. The vendor shall adhere to the following chronological fabrication sequence unless an alternative is approved in writing by the TPOC:

a. Phase 1 - Foundation: Erect formwork for the main foundation slab and the footings for the exterior retaining walls. Install all reinforcing steel and embedded items. After TPOC inspection, place, consolidate, and cure the concrete.

b. Phase 2 - Walls: Erect and brace the complete interior and exterior formwork systems for the main structural walls. Install reinforcing steel cages and any embedded items. After TPOC inspection, place, consolidate, and cure the wall concrete.

c. Phase 3 - Cavity Protection: Immediately after wall formwork is removed, provide and maintain temporary, weatherproof covers over all open wall cavities to prevent moisture and debris intrusion.

d. Phase 4 - Cavity & Retaining Wall Assembly:

i. Once cavities are inspected and verified as clean and dry by the TPOC, install structural sand fill to the specified density.

ii. Concurrently, form, reinforce, and place concrete for the vertical stems of the exterior retaining walls (wing walls).

Note: Immediately after sand is installed, provide and maintain temporary, weatherproof covers over all open wall cavities to prevent moisture and debris intrusion.

e. Phase 5 - Roof Slab & Parapets: Erect all elevated shoring and formwork for the roof slab and integrated parapets. Install all roof reinforcing steel mats. After TPOC inspection, place, consolidate, and cure the concrete for the roof slab and parapets monolithically.

f. Phase 6 - Door Assembly: After the main structure formwork is removed, erect formwork, install rebar, and place concrete for the three specialized blast doors. Subsequently, install the specified steel closure plates.

g. Phase 7 - Protective Cover: After the entire concrete structure has achieved its full 28-day design strength, place the specified sand/earth protective berm over the roof and against the exterior retaining walls.

3.3 Concrete Placement and Tolerances:

o 3.3.1 Concrete shall be placed from the bottom up in a continuous operation for each wall pour, with the placement rate controlled to manage formwork pressure. A detailed placement plan is required for TPOC review.

o 3.3.2 The final, assembled structure’s overall dimensions shall be within a tolerance of +/- 0.5 inches.

o 3.3.3 Wall and slab thicknesses must be within +/- 0.375 inches

4.0 QUALITY ASSURANCE & TESTING

• 4.1 Pre-Placement Inspections (Hold Points): The vendor shall not commence concrete placement for any structural element (foundation, walls, roof, doors) until a formal inspection is completed by the TPOC. The vendor must provide a minimum of 48 hours' written notice prior to requesting an inspection. The TPOC will verify:

o 4.1.1 Formwork dimensions, stability, and cleanliness.

o 4.1.2 Reinforcing steel size, spacing, continuous bar routing, and tying accuracy.

o 4.1.3 Correct clearance (concrete cover) between the reinforcing steel and the formwork.

o 4.1.4 Proper location and securement of all embedded items and sleeves.

4.2 Material Testing: For each distinct concrete placement event, the following testing protocols apply:

o 4.2.1 A minimum of six (6) 4x8-inch test cylinders shall be cast. Three (3) cylinders shall be tested at 7 days and three (3) at 28 days to verify compressive strength per ASTM C39. Certified break data must be provided to the TPOC.

o 4.2.2 An additional three (3) test cylinders must be cast, field-cured alongside the structure, and delivered to the ERDC designated lab for follow-on Government testing.

o 4.2.3 On-site plastic concrete properties must be verified for each batch. This shall include, at a minimum, tests for slump flow (ASTM C1611), T-50, and J-Ring (ASTM C1621) to ensure the SCC meets the approved mix design's flowability characteristics. Results must be documented and provided to the

TPOC.

4.3 Fill Inspection: The TPOC must inspect the hollow wall cavities prior to the installation of the structural sand fill. This inspection will verify the cavities are free of debris and are completely dry. The vendor shall remove any standing water and ensure surfaces are dry before the TPOC inspection.

4.4 Final Inspection: A final inspection of the completed structure will be performed by the TPOC to ensure overall dimensional tolerances are met, concrete surfaces are acceptable, and no structural cracking is present.

5.0 VENDOR RESPONSIBILITIES

• 5.1 Means and Methods: The vendor shall be responsible for all means and methods required for the on-site assembly, including but not limited to, equipment for formwork erection, rebar installation, and concrete placement (e.g., cranes, concrete pumps, vibrators).

• 5.2 Logistics and Coordination: The vendor is responsible for coordinating all material and equipment deliveries and managing all on-site logistics.

• 5.3 Company Eligibility: The contractor performing this work must be a United States (US) owned company.

6.0 PRICING

The contractor shall provide firm-fixed pricing for the complete procurement, fabrication, assembly, and finishing of one

(1) three-bay HPM structure as specified herein. Pricing must be inclusive of all materials, equipment, labor, and travel required to deliver the final, assembled structure.

7.0 DELIVERY & SCHEDULE DETAILS

• 7.1 All site activities must be completed, and the final structure ready for inspection, NLT 240 days after contract award.

• 7.2 The vendor must provide the TPOC a minimum notice of 14 calendar days prior to mobilizing equipment to the site.

• 7.3 The vendor shall coordinate all site access with the TPOC and adhere to all installation security and safety protocols.

• 7.4 Inspection Scheduling and Notification: The vendor is responsible for providing a written notification to the

TPOC to schedule all mandatory inspections specified in Section 4.0. The following minimum notification periods are required in advance of the requested inspection time:

o 7.4.1 Pre-Placement Concrete Inspections: A minimum of 48 hours' notice is required for all concrete placement hold points (foundation, walls, roof, doors).

o 7.4.2 Pre-Fill Cavity Inspection: A minimum of 48 hours' notice is required for the sand fill cavity inspection.

o 7.4.3 Final Inspection: A minimum of 5 business days' notice is required to schedule the final project acceptance inspection.

8.0 DELIVERY LOCATION

Range 19, Mill Creek Road

Fort Polk, Louisiana 71459