B6 - Questions and Answers - Dated 21 May 2025.pdf

QUESTIONS AND ANSWERS RELATED TO :

SOLICITATION W50S7L-25-B-A002

As of 21 May 2025

Q1. Concrete Mix Design Requirements

The concrete mix design requirements—including detailed proportioning studies and aggregate quality testing. This includes: - Aggregate testing conducted within one year of submittal (1.3.2.1), - 28-day ASR testing and petrographic analysis via ASTM C295 for coarse aggregates (2.3), - Three-point mix design curve (2.13.2). These requirements demand substantial time and financial investment from bidders during the proposal phase.

We respectfully request confirmation that no changes to these requirements will be made post-award.

A1. These specifications are to meet Airfield Concrete requirements, specification is pulled from most recent USGS. Please note first statement in Section 32 13 14.14 Pg 77, 2.1 on existing mix design availability.

Q2. Concrete Discharge Time Limits

This paragraph limits concrete placement to within 90 minutes of cement discharge into the mixer. However, modern hydration stabilizers effectively extend the workable life of concrete. Given that the project involves many small-volume placements, allowing an extended discharge time would: - Improve batching efficiency, - Enhance consistency across placements, - Reduce risk of cold joints. We request approval to extend the allowable discharge time to 150 minutes when hydration stabilizers are used.

A2. Allowable discharge time can be extended to 150 minutes when hydration stabilizers are used. Hydration stabilizers must be in the concrete design if used.

Q3. Clarification on Overcutting

Is overcutting allowed on the 42” x 42” x 9” cutout sections during demolition or replacement? Please clarify if there are dimensional tolerances or constraints on overcutting these concrete removal areas. If overcutting is permitted, are there restrictions on maximum allowable overage or backfill/repair procedures?

Q3. Overcutting is allowed on the cutout sections. Contractor to cut the minimal amount of overcutting to allow for the bottom intersection of concrete to be cleanly cut.

Q4. Existing PCC Pavement Testing Requirements

Are there any Government requirements for coring or testing the existing Portland Cement Concrete (PCC) pavement prior to or during demolition and replacement? Please clarify whether the following are required: - Compressive strength testing - Environmental (e.g., hazardous materials) testing - Thickness verification - Condition assessment (e.g., delamination, cracking, etc.) Additionally, if coring or in-situ testing is required, please specify: - Test frequency, - Acceptable testing methods (e.g., ASTM standards), - Whether government will provide historical test results (if available).

A4. No coring or testing of the existing PCC pavement is required. Testing frequency of new concrete will follow specifications in Section 32 13 14.14. Subsection 3.11

Q5. Joint Repair & Sealing

Please state the unit counts in LF of the joint repair and sealing, and advise if spalling repair is part of this task? If so, what SQ of spalling repair is to be completed?

A5. Joint seal, Detail C-201 #1 has approximately 5,400 linear feet. Spall repair is not a part of this task.

Q6. Barricades & Free Zone

Please advise if this project will have a free zone. If so, what are the operational constraints of the free zone (i.e. can equipment be left overnight).

Please also confirm which barricades are required, who supplies them, and if they are to encompass the entire work area or will be moved in phases (i.e. per parking space).

A6. Montana Air National Guard Free Zone will exist and there will be no operational constraints within freezone. Freezone does not extend into the controlled movement area, which is controlled by the FAA tower. Equipment can be left overnight, however, must be in a stored position and cleaned up to prevent FOD. Barricades are required at connections to the taxiway and operational apron. Additionally, barricades will be required when the taxiway is closed for work within the controlled movement area. Barricades are to be provided by the contractor.

Q7. Deployment Prerequisites

Has an FAA Obstruction Study been initiated? If not, will that be the government’s responsibility or contractors?

Has an airfield waiver been initiated? If not, will that be the government’s responsibility or contractors?

A7. FAA Obstruction Study not required, not constructing any new vertical structure. Airfield notice FAA 7460-1 filed by government.

Q8. Grounding Rods

For installation of the grounding rods, at what depth is the weathered sandstone encountered?

A8. Weathered sandstone at MTANG is approximately 4’ below grade. Historically, to provide adequate depth for the not less than 10 ft long rod, coring with a drill rig was used. Once grounding rod is installed, backfill cored hole with material that provides not more than 10,000 ohms of resistance.

Q9. Sheet C-201 Expansion Joints

Asphalt to concrete joints shows 1 ½” wide x ½” deep min with no backer rod / industry standard ¾” to 1” wide with backer rod .

NOTES : States a completely different joint seal calls for compression seal, this material is a rigid material not a pourable material. Compression seal is not compatible to an asphalt to concrete joint.

A9. The asphalt to PCC joint sealant isn’t designed to be a compression joint. Delete the last portion of C-201 Expansion Joint Note 4 – “ AS AN EQUAL TO RPREFORMED

COMMPRESSION SEALER”

Deleted Note 3.

See Drawing revisions dated May 21, 2025 for specifics.

The hot applied sealant doesn’t need to be fuel resistant. No backer rod is required. The sealant must meet ASTM D6690 Type III PER the detail. The basis of design sealant is Crafco

ROADSAVER 222

Q10. Joint Seal

What type of Joint seal for construction joints around the tie downs jet fuel resistance?

A10. DOWSIL 890-SL is currently being used around the existing tiedowns.

Q11. Expansion Joint Linier Footage

What is the linier footage for the expansion joint replacement area?

A11. Main Ramp = 2,034LF Spot 13/M8 & M9 = 258 LF Total = 2,292