RFI_Responses___Taxiway_B,H,J_-_2.pdf

RFI Questions / Responses ‐2

Project Title: Taxiway Bravo, Hotel, and Juliet – Paving / Lights Location: Selfridge ANGB, MI Solicitation Number: W912JB19B5000

RFI: Concrete Depth Removal – Old Taxiway @ Station 31+00 RFI Question: “Please provide as built / make up of concrete to be removed at Station 31+00 or Please provide depth of concrete to be removed. “

Answer: The last documents 127th Engineering can find: 2.5‐3.5” ACC over 12‐14” PCC (1968). It is unknown if Steel is within Concrete. None is anticipated, but should be planned for.

RFI: New Concrete Patch – MDOT Detail‐7

RFI Question: We would like the 127th Engineering to consider using a MDOT Detail‐7, to replace the current Concrete Patch method. Please consider. If formally agreed to, please provide a specification for this mix to be used.

Answer: This solution is acceptable to the Government. i. Approximately 30,000LF of joint/slab repair. Repairs to be identified with, and agreed upon, between the contractor and Government inspectors.

RFI: Concrete Patch’s – Specification:

RFI Question: The two concrete specifications provided in the original bid package are SECTION 033000 – CAST IN PLACE CONCRETE which covers footings, light pole bases, manholes and control, expansion & contraction joint devices and SECTION 32 16 19 which covers concrete curbs, gutters and sidewalks.

Please provide or direct us to what specification shall be used for this concrete.

Answer: Concrete not used on taxiway repairs (see above RFI answer).

RFI: Elevations:

RFI Question: Plan drawings only provide detail proposed grades for top of pavement in intersection areas. The remaining 90% of the project does not have proposed grades for top of pavement on the plans.

Specifications state final paving tolerance of 1/4" ‐/+ from 0. This surely can be achieved by a paver with 3D machine control technology in the few intersection areas where proposed pavement grades are provided. To meet the very tight specification on tolerances for ride, slope and grade the entire project has to be paved with 3D machine control technology. Since 90% of the job is to be profile milled (Only Mill to Concrete) this will achieve cross slope but any longitudinal bumps along profile will remain. This will result in not meeting the ride and smoothness required by the specification.

In addition, it states that we are to mill to top of concrete and no more. Based on the cores we will be milling from 1 inch to 2.75 inches. This variable milling depth we also require proposed grades for top of pavement to place the leveling course in order to meet the ride specification.

The leveling course will vary in thickness due to the variable depth milling. If we are to mill variable depth as stated in the RFI and place uniform lifts of asphalt we will also not meet the ride specification.

If the Government provides proposed grades in all of pavement areas a 3D proposed digital model could be created and used in both the milling and paving operations with machine control technology to meet the 1/4" tolerances and this solve this issue.

How shall the we Proceed?

Answer: New Grading Sheets provided.