Concrete Pad For Nitrogen Tank Placement

Provide all materials, labor and technical support (approved Lab support) as necessary, to install a concrete pad for a WANCDF Nitrogen Storage Tank to be used to operate a Nitrocision system. The concrete pad shall be 20'-0" long x 20'-0" wide x 22" deep and shall be located and installed on WANCDF site, as shown on the attached drawings. Installation 1. The selected contractor shall cut through the surface slab down to the grade beneath and remove the excavated materials and if required replace with a select fill dirt. Add 8" maximum layers of backfill, as required, and compact to 2000 PSF, verify with Penetrometer reading. See "Testing" section. Notify QA/QC at time of test for Witness point. 2. The contractor shall install all concrete formwork (4" rise above existing concrete), rebar and pour concrete according to the attached civil drawing C-05 and respective notes. 3. The contractor shall collect and remove all demolished materials and waste generated during the construction period. Testing Requirements: 1. Contractor shall be responsible for contracting a LAB to test the specimens for the purpose of determining the characteristics of the concrete, at given points in time. Reference item # 5 under "General" in this document. 2. The contractor shall provide a calibrated Penetrometer and an authorized user for verification of the compacting as described in item #1 "Installation" in this document. 2000 PSF is the compaction requirement as tested in each of the four corners of the pad area and in the center of the pad area. QA/QC Witness Point 3. QA/QC shall verify proper reinforcement placement in accordance with drawing C-05. QA/QC Witness Point. 4. QA/QC shall verify concrete mix and delivery time. Notify QA/QC prior to delivery to inspect batch ticket. Per item #8 "General" this document. QA/QC Witness Point General: - 1. The contractor shall coordinate all activities with WANCDF operations. - 2. Contractor shall provide material cut sheets/specs for WA records. - 3. The contractor shall verify all existing field conditions, dimensions, and elevations before proceeding with construction. The contractor shall locate all existing underground utilities and protect from damage during excavating operations. Contractor shall provide a GPR survey which shall locate any underground interference. - 4. The contractor shall protect buildings, adjacent features, walkways, site improvements, exterior paintings, landscaping, etc., as required, from damage. The contractor shall correct damages resulting from construction activities. - 5. Where specific, detailed instructions are not addressed in the attached documents, applicable codes and standards apply, along with standard acceptable "skill of craft" practices and procedures. - 6. Concrete: 28 day ultimate compressive strength of 4000 PSI. WEBB mix # RM4020 or approved equal. Contractor shall provide 1 set of 2 specimens at 7days, 10 days and 28 days. Two additional specimens shall be provided, to be broken on demand. Provide QA./QC with test result once breaks are made. - 7. Comply with CRSI'S "Manual of Standard Practices" for fabricating, placing, and supporting reinforcement. WA QA/QC shall verify reinforcement placement in accordance with C-05 drawing. QA/QC Witness Point. - 8. Measure, batch, mix and deliver concrete according to ASTM C94/C94M and ASTM C1116. When air temperature is above 90 degrees F, reduce mixing and delivery time to 60 minutes. Upon delivery and prior to pouring QA/QC shall verify delivery time and mix using the batch ticket. If concrete is not delivered in allotted time but workability can be objectively verified (i.e. slump within 2" to 5" range) concrete shall be acceptable. QA/QC Witness Point. - 9. Protect concrete from physical damage, premature drying, and reduced strength during mixing, placing and curing due to hot weather conditions. Hot weather placement shall comply with ACI-301. - 10. Moisture-Retaining cover shall conform to ASTM C171 and be polyethylene film or white burlap-polyethylene sheet. - 11. Place concrete in a continuous operation and consolidate using mechanical vibrating equipment. - 12. Exterior horizontal concrete surface shall have a broom finish to provide a nonskid surface for personnel traffic. - 13. Begin curing concrete slab after finishing. Keep concrete continuously moist for at least seven days. Contractor shall provide soaker hoses to maintain the wetted condition for the full seven day period. WA maintenance shall monitor and ensure proper curing is maintained. QA/QC shall maintain surveillance to ensure proper curing. - 14. Do not add water to concrete during delivery, at project site, or during placement unless approved by engineer. - 15. Lap all reinforcing splices at least 48 bar diameters (24" minimum) unless otherwise noted. Splice locations shall be staggered for parallel bars. - 16. The contractor shall provide and install new compacted crushed stone on top of the exposed or compacted grade and provide a Polyethylene vapor barrier on top of the crushed stone. The Polyethylene shall be not less than 10 mils thick. - 17. The contractor shall chamfer exposed edges of concrete ", unless otherwise noted. - 18. All testing and inspections to ensure that the final installation performs as designed.