Addendum_1.docx

Addendum 1 Design and Construct New Braking Pads – GRCA 07-0202015

Questions and Responses from Pre-Bid Meeting, June 23, 2015

1. Question: Is there a soils engineering or geotechnical report for Hermit Road and the South Entrance Station?

Answer: There are no existing soils engineering or geotechnical reports for either location.

2. Question: Will the NPS be providing testing or are there testing requirements?

Answer: The NPS will not provide testing services; however, the contractor is responsible for all testing and inspections through an independent testing agency. At a minimum, testing will be required for subgrades and compaction, asphalt and concrete:

a. Testing Agency: Contractor will engage and pay for a qualified independent testing and inspecting agency to perform field tests and inspections and to prepare test reports.

i. Testing agency will conduct and interpret tests and state in each report whether tested work complies with or deviates from specified requirements.

ii. Additional testing and inspecting, at Contractor's expense, will be performed to determine compliance of replaced or additional work with specified requirements.

b. Concrete Testing:

i. Testing Agency: Field testing and inspection shall be made by an approved testing laboratory selected and paid by General Contractor.

ii. General Contractor will select laboratory and pay for tests.

iii. Tests shall conform to ASTM C39.

iv. For each strength of concrete used, take 6 cylinders for each day's pour.

v. Test 3 cylinders at 7 days and 3 at 28 days.

vi. When, in opinion of Contracting Officer, there is a possibility of surrounding air temperature falling below 40 degrees F, additional specimens to be cured under job conditions may be required.

3. Question: The Bid Schedule does not include Option G.

Answer: A revised Bid Schedule is attached.

4. Question: Would the NPS consider the potential for nighttime work?

Answer: Yes, the NPS would allow for extended work hours at the South Entrance Station, only. Work hours could begin as early as 5:00 am and could go as late as 10:00 pm. These extended work hours would need to be approved 7 days in advance of actual work. It’s assumed that poring of concrete would only occur during daylight hours and that this would apply predominantly to loud demolition work.

5. Question: What color should the concrete walks be for Option G?

Answer: The concrete should match the existing walkways for Option G. The concrete lanes in the base bid should be grey (without color) at the South Entrance Station.

6. Question: Do you require caulking of the construction joints?

Answer: Yes, as specified by the contractor and approved by the NPS.

7. Question: There appears to be an additional section of concrete that has failed at Maricopa Point. Do you want to add this to the project?

Answer: Yes. Maricopa Point is CLIN item 4 and is included in the Base Bid. Add an additional section for removal and replacement. This section is on the approach to the bus braking pad and measures 9.5’ x 12’. This would be in addition to areas A and B. (no modified drawing is attached).

Schedule times for tests, inspections, obtaining samples, and similar activities.

A. Testing agency will test compaction of soils in place according to ASTM D 1556, ASTM D 2167, ASTM D 2922, and ASTM D 2937, as applicable. Perform field moisture tests in accordance with ASTM D3017. Tests will be performed at the following locations and frequencies at a minimum:

1. Paved and Building Slab Areas: At subgrade and at each compacted fill and backfill layer, at least 1 test for every 2000 sq. ft. (186 sq. m) or less of paved area or building slab, but in no case fewer than 3 tests.

B. When testing agency reports that subgrades, fills, or backfills have not achieved degree of compaction specified, scarify and moisten or aerate, or remove and replace soil to depth required; recompact and retest until specified compaction is obtained.