032A RFQ Amendment-attachement QA.docx

Questions and Answers NIST Solicitation No. AMD-TC-RQ-22-02599 Removal of ASR Concrete Block Specimens

1. The building that the concrete blocks are to be removed contains government equipment that needs to be removed. How does the government propose to protect this equipment?

· Answer: All equipment will be removed from the work area surrounding the concrete blocks to facilitate access for the demolition and removal work to be performed.

2. Is there any type of design drawings of the concrete specimens?

· Answer: Yes, attached is a picture consisting of a poster that contains details of the specimen design and instrumentation; materials, construction, and curing; and expansion monitoring of the concrete blocks.

3. Can you provide details of the concrete mixture and what the concrete is made from? For example, the blocks have rebars. However, the rebar does not look like the standard type. Can we get the rebar specifications?

· Answer: The concrete mixture is typical normal-weight, normal strength concrete with Alkali-Silica reactive coarse aggregate. The typical concrete compressive strength f’c is about 5,000 psi.

· All rebars are typical deformed ASTM standard steel rebar for concrete reinforcement. They are of different sizes (diameters), with nominal tensile strength fy of 60 ksi (Grade 60).

4. These concrete blocks appear to be very dense and high strength. What are the specifications of the concrete mix?

· Answer: No, they are not very dense and high strength. They are typical normal-weight, normal strength concrete with f’c of about 5,000 psi and normal density (approximately about 150 lb/ft3). Also see answer to question 3 above.

5. Will the government allow off-hour and weekend work, due to possible noise and dust from breaking apart and removing the blocks?

· Answer: Yes, the Statement of Work states that the contractor shall make arrangements with the Government for the concrete demolition and removal to be executed during the weekend in order to avoid disruption of business activities, which occur at NIST during normal business working days from Monday through Friday.