Amendment_0004.pdf

AMENDMENT OF SOLICITATION/MODIFICATION OF CONTRACT

Except as provided herein, all terms and conditions of the document referenced in Item 9A or 10A, as heretofore changed, remains unchanged and in full force and effect.

15A. NAME AND TITLE OF SIGNER (Type or print)

30-105-04EXCEPTION TO SF 30

APPROVED BY OIRM 11-84

STANDARD FORM 30 (Rev. 10-83) Prescribed by GSA

FAR (48 CFR) 53.243

THE PROPOSAL DUE DATE REMAINS 26 JULY 2018

The purpose of this amendment is to:

1. Respond to Pre-Proposal Inquiries (PPIs)

2. Update stiffness requirement

3. Update testing requirments

1. CONTRACT ID CODE PAGE OF PAGES

J 1 17

16A. NAME AND TITLE OF CONTRACTING OFFICER (Type or print)

16C. DATE SIGNED

BY 10-Jul-2018

16B. UNITED STATES OF AMERICA15C. DATE SIGNED15B. CONTRACTOR/OFFEROR

(Signature of Contracting Officer)(Signature of person authorized to sign)

8. NAME AND ADDRESS OF CONTRACTOR (No., Street, County, State and Zip Code) X N4008518R8720

X 9B. DATED (SEE ITEM 11)

05-Jun-2018

10B. DATED (SEE ITEM 13)

9A. AMENDMENT OF SOLICITATION NO.

11. THIS ITEM ONLY APPLIES TO AMENDMENTS OF SOLICITATIONS

X The above numbered solicitation is amended as set forth in Item 14. The hour and date specified for receipt of Offer is extended, X is not extended.

Offer must acknowledge receipt of this amendment prior to the hour and date specified in the solicitation or as amended by one of the following methods:

(a) By completing Items 8 and 15, and returning 1 copies of the amendment; (b) By acknowledging receipt of this amendment on each copy of the offer submitted;

or (c) By separate letter or telegram which includes a reference to the solicitation and amendment numbers. FAILURE OF YOUR ACKNOWLEDGMENT TO BE RECEIVED AT THE PLACE DESIGNATED FOR THE RECEIPT OF OFFERS PRIOR TO THE HOUR AND DATE SPECIFIED MAY RESULT IN

REJECTION OF YOUR OFFER. If by virtue of this amendment you desire to change an offer already submitted, such change may be made by telegram or letter, provided each telegram or letter makes reference to the solicitation and this amendment, and is received prior to the opening hour and date specified.

12. ACCOUNTING AND APPROPRIATION DATA (If required)

13. THIS ITEM APPLIES ONLY TO MODIFICATIONS OF CONTRACTS/ORDERS.

IT MODIFIES THE CONTRACT/ORDER NO. AS DESCRIBED IN ITEM 14.

A. THIS CHANGE ORDER IS ISSUED PURSUANT TO: (Specify authority) THE CHANGES SET FORTH IN ITEM 14 ARE MADE IN THE

CONTRACT ORDER NO. IN ITEM 10A.

B. THE ABOVE NUMBERED CONTRACT/ORDER IS MODIFIED TO REFLECT THE ADMINISTRATIVE CHANGES (such as changes in paying office, appropriation date, etc.) SET FORTH IN ITEM 14, PURSUANT TO THE AUTHORITY OF FAR 43.103(B).

C. THIS SUPPLEMENTAL AGREEMENT IS ENTERED INTO PURSUANT TO AUTHORITY OF:

D. OTHER (Specify type of modification and authority)

E. IMPORTANT: Contractor is not, is required to sign this document and return copies to the issuing office.

14. DESCRIPTION OF AMENDMENT/MODIFICATION (Organized by UCF section headings, including solicitation/contract subject matter where feasible.)

10A. MOD. OF CONTRACT/ORDER NO.

2. AMENDMENT/MODIFICATION NO. 5. PROJECT NO.(If applicable)

6. ISSUED BY

3. EFFECTIVE DATE

10-Jul-2018

CODE

NAVFAC MID ATLANTIC

9324 VIRGINIA AVENUE

BLDG Z-144

NORFOLK VA 23511

N40085 7. ADMINISTERED BY (If other than item 6)

4. REQUISITION/PURCHASE REQ. NO.

CODE

See Item 6

FACILITY CODECODE

EMAIL:TEL:

N4008518R8720

SECTION SF 30 BLOCK 14 CONTINUATION PAGE

SUMMARY OF CHANGES

SECTION SF 30 - BLOCK 14 CONTINUATION PAGE

The following have been added by full text:

AMENDMENT 0004

CONTINUATION SHEET

On NAVFAC Dwg. No. 12768380 (G101) Revise duration of Phases 1 through 3 to 210 calendar days.

Revise duration of Phases 4 through 7 to 1210 calendar days

On NAVFAC Dwg. No. 12768387 (S001) Under heading “BOX BEAM STRENGTHENING,” delete “illustrated on this sheet.”

On NAVFAC Dwg. No. 12768427 through 12768429 (S606 through S608) Replace the following values in all of the strengthening schedules for both flexural and shear Cured CFRP Stiffness.

Strengthening

Type Original Replace

With 1 1120 k/in 950 k/in 2 2240 k/in 1900 k/in 3 3360 k/in 2850 k/in

SECTION 03 25 00 EXTERNALLY BONDED CFRP FABRIC SYSTEMS

1.3 SUBMITTALS

SD-05 Design Data Delete paragraph in its entirety and replace with the following:

“Submit calculations sealed by a CFRP Engineer registered in the State of New Jersey showing that the proposed CFRP system meets or exceeds the requirements of this specification. The calculations should show that the proposed system provides the tensile stiffness per inch width greater than or equal to the stiffness specified on the drawings.”

2.2.g.3 Unidirectional Carbon Fiber CFRP System per layer:

Add “Maximum” in front of “Thickness per layer” at the bottom of the first column.

3.1.3 Access to Work Area

Delete second sentence and replace with the following:

It is envisioned that due the scale of this project the contractor should consider installing temporary hanging fixed work platforms from the existing trestle or supplying stable work floats with large surface area greater than the length and width of each beam.

3.5.5 CFRP System Tensile Testing

Delete Paragraph a. in its entirety and replace with the following:

a. Make witness panels from the same fiber, saturating resins, equipment, and methods used in the installation of the CFRP system. At a minimum, create two 12" by 12" witness panels for each day of production.

Mark the panels with the date of fabrication, and location of application. Prepare samples on a flat, level surface covered with heavy-duty vinyl (or similar). Prime vinyl with saturant, place saturated layers, and apply a top coat of saturant.

3.5.5 CFRP System Tensile Testing

Delete Paragraph c. in its entirety and replace with the following:

c. One panel from a minimum of 10% of all sample sets shall be selected for tension testing performed in accordance with ASTM D7565 and/or ASTM D3039. Send panels to a third party laboratory experienced with the tensile testing of CFRP materials within two weeks of fabrication. Tension tests shall be performed to verify the tensile strength, strain, and modulus (stiffness) of the composite strengthening system based on the nominal layer thickness reported on the manufacturer’s data sheet and used in the stiffness calculations.

The composite tensile stiffness properties used in the stiffness calculations must be lower than the average of the test results.

3.5.9 Inspection for Adhesion to Substrate

Delete second sentence and replace with the following:

Conduct adhesion testing at a frequency of two tests per beam.

Questio n No.

QUESTION GOVERNMENT RESPONSE

3 The specification calls out both AASHTO FRP and ACI 440.2R FRP guides. It is not possible to use the AASHTO FRP guide to calculate the flexural behavior since the peeling equations require the designer to know the shear stiffness of the resin (shear modulus and thickness).

While the shear stiffness is important to the overall behavior, it’s not clear how this will be controlled by the contractor in the field or how the bond line thickness will be inspected.

Suggest you remove all references to the

AASHTO guide and make entire design based on ACI 440.2R or provide further guidance on how to use AASHTO.

The design can be based on ACI 440.2R. Calculations are only required to show that the provided cured FRP meets the stiffness (EA) shown on the Construction Documents. Section SD-05 will be revised to reflect this change.

4 SD-05 section of the submittal section of the specification requires calculations to be submitted. These calculations cannot be done using the AASHTO Guide. Recommend all calculations be done using the ACI 440.2R

Guide.

The only calculations required are those that show the provided FRP meets the EA shown on the plans.

Section SD-05 will be revised to reflect this change.

5 SD-05 section of the submittal section of the specification requires calculations to be submitted. It’s not clear why an effective strain would have to be calculated since the performance requirements shown on the plans define the EA for each box beam. The EA shown on the plans will have a corresponding effective strain which presumably has already been calculated by the Engineer of Record. Is it sufficient to show the provided FRP (number of layers, thickness, modulus) meets the EA shown on the plans?

The only calculations required are those that show the provided FRP meets the EA shown on the plans.

Section SD-05 will be revised to reflect this change. See

Amendment 0004

6 The table or minimum properties listed in the specification lists 0.08” thickness per layer. This appears to be a typo. Do you mean the maximum thickness per layer?

The 0.08" should be the maximum thickness per layer. See

Amendment 0004

7 Can thinner layers be used provided the total EA required per box beam is met or exceeded?

Since you are defining the minimum EA required per box beam it does not matter what ply thickness is used provided the total number of layers meets or exceeds the specified EA for that box beam. For this project, it may be easier to use thinner layers but more of them.

Shouldn't this be left up to the contractor to decide how to execute the job based on the conditions?

Yes, thinner layers are acceptable. It is up to the contractor/FRP manufacturer to determine the total number of layers based on the selected product to achieve the required cured CFRP tensile stiffness

8 I do not see any reference to “field-thickened resin” in the list of constituent materials listed in Paragraph 2.2. Can the contractor modify the formula of the resins in the field?

The manufacturer of the strengthening system will need to determine if field-thickened resins can be used on their system and still meet all of the requirements in

Specification Section 03 25 00. This is a bond critical application and if Cab-O-Sil reduces the bond below those required by the specification it will be rejected.

9 Is it correct to assume that field-thickened resins made by adding filler materials like Cab-o-Sil to the saturating resin will not be allowed to be used between the first layer of FRP and the concrete substrate or between FRP layers since this is bond-critical application?

The manufacturer of the strengthening system will need to determine if field-thickened resins can be used on their system and still meet all of the requirements in

Specification Section 03 25 00. This is a bond critical application and if thickening reduces the bond below those required by the specification it will be rejected.

10 Field thickening resins with Cab-o-Sil or other lightweight fillers makes them very brittle.

Please provide the minimum elongation of a field thickened resin that is acceptable without compromising the Engineer’s effective strain calculations and FRP design. Will the contractor be required to submit a ASTM D638 or ASTM D790 testing showing the field thickened resin provides sufficient elongation to not impact the design?

The manufacturer of the strengthening system will need to determine if field-thickened resins can be used on their system and still meet all of the requirements in

Specification Section 03 25 00. If a thickened resin is used, the contractor will need to prove, through applicable testing, to the manufacturer and NAVFAC that sufficient elongation will be achieved.

11 Paragraph 3.5.5 of the specification states that the average tensile strength of the FRP system should exceed 1120 kip/inch/ply or it will be rejected. I think you mean average tensile stiffness. Please clarify.

Correct, this should be revised to the average tensile stiffness not average tensile strength. See Amendment 0004

12 Assuming the acceptance value of 1120 kips/inch/ply is tensile stiffness you need to modify the acceptance criteria. In accordance with ACI 440.2R, the tensile stiffness is calculated as an average value not a guaranteed value (average minus three standard deviations). Your current acceptance value will result in half of all tests failing.

The acceptance criteria has been revised to 950 k/in/ply for a 0.8" thickness. If thinner plies are used, than this number will be different.

This requirement has been revised and updated in Amendment 0004

13 Paragraph 3.5.5 of the specification states the average tensile strength of the FRP system should exceed 1120 kip/inch/ply or it will be rejected. Assuming you mean tensile stiffness, the value of 1120 kips/inch/ply exceeds the minimum properties specified in the table in

Section 2.2. The calculated tensile stiffness of the specified product is 968 kips/inch/ply.

The modulus of elasticity shown in Paragraph 2.2.g.3 is correct. The required tensile stiffness will be revised in Amendment 0004.

14 It appears the FRP design and the specification was based on a product supplied by Structural Technologies. Are you aware that Structural

Technologies is affiliated with Structural Preservation Systems? How will you assure the Navy receive competitive bids for this project if Structural Technologies chooses to not provide competitive pricing to contractors competing with Structural Preservation Systems?

Three approved products are listed in the specifications 2.1.1.

15 To be sure the Navy receives competitive bids from more than a single FRP installer, please provide the moment and shear demands/diagrams and as-builts drawings so that we can prepare our own FRP design to submit? Please extend the bid date to enable an FRP design to be made.

Contractor shall price the FRP system based on tensile stiffness criteria provided in the Construction Documents. Calculations do not need to be prepared based on moment and shear demand.

16 Please confirm that FRP anchors are not allowed and will not be considered as value engineering option?

FRP anchors are not permitted

17 The design appears to require an extraordinary amount of carbon per box beam. Have the unstrengthened member checks of ACI 440.2R (Eqn 9.2) or of AASHTO (Eqn 1.4.4-1) been satisfied for this project?

The unstrengthen members have been checked and do satisfy the both the ACI and AASHTO equations referenced.

18 Please confirm that the only new anodes and HDPE sleeves to be installed on the project are on the newly installed piles for the 5 supplemental bent caps?

Correct, only the 10 new piles are to receive the anodes and HDPE Sleeves

19 Are there any restrictions on fabrication splicing of the piles for the new supplemental bents beyond what is called out in spec section 31 62

23.13 subsection 3.2.2.1?

In addition to the requirements in Paragraph 3.2.2.1, the contractor will need to meet all tolerances, testing and quality control requirements.

20 Can an extension be given from the July 19th due date for all proposals?

See Amendment 0003

21 How long will the Performance & Payment Bonds remain in effect for? Does the

Performance & Payment Bond have to remain in effect for the entire warranty period?

P&P bonds are in effect until the final invoice is paid and the contract closed.

22 Are there any phasing requirements for this project? In other words, how many beams can the contractor work on simultaneously?

Phasing requirements are identified on sheet G101. There is no limit to the number of simultaneous beams that can be worked on, but the overall plan needs to be coordinated with the COR. The Trestle must remain operational at all times.

Which means one rail and one lane access must be remain open to and from the three Piers.

23 In specification section 032500, Para. 3.2 A calls out to make all substrate concrete repairs in accordance with application specifications. Can you please confirm that these concrete repairs shall be paid under bid item CLIN - 0001AH - Concrete Spall Repairs. If not then please provide a quantity for the required substrate concrete repairs that shall get paid under the CFRP bid items.

Confirmed. All concrete spall repairs should be paid under CLIN

0001AH.

24 For bidding purposes, please clarify what the expectations are as it relates to determination of existing corroded reinforcement. The specifications say that CFRP cannot be installed on surfaces suspected of containing corroded reinforcement or reinforcement which could exhibit AAR. At this time, it is not possible for the contractors to make this determination.

How should contractors address this in their bids, if at all?

For bidding purposes the Contractor shall assume that the reinforcing is not corroded and there is no AAR.

25 In specification section 032500, Para. 3.2 C calls out to inject all cracks wider than 0.01 inches with epoxy resin under pressure. Due to the site conditions, it is not possible to obtain a quantity for this item without inspecting each and every beam receiving FRP. In addition this is an expensive repair. Can you please provide a bid quantity for epoxy injection of resin under pressure?

For bidding purposes assume crack injection is not required. The surfaced of the box beams show very little cracking, with most cracks less than 0.01 inches.

26 Can you please confirm that stamped and sealed drawings and calculations submittal shall be required for the CFRP work shown on the bid documents?

Stamped and sealed drawings are only required for the calculations that show the selected product meets the minimum cured CFRP stiffness (EA) identified in the Contract Documents

27 Please confirm that an independent testing agency shall be retained and paid by the

Contractor for the entire CFRP scope of work.

Correct, contractor is responsible for all testing via an independent testing agency.

28 In addition, please confirm that an independent QC inspector shall be retained and paid by the

Contractor for the entire duration of CFRP installation work for daily field inspection.

Correct, daily field inspection is required during installation of the CFRP. Refer to specification Section 03 25 00 and 01 45 35 for Special Inspection requirements pertaining to the CFRP installation. In particular, the Schedule of Special Inspection at the end of Section 01 45 35, Table B.

29 In specification section 032500, Para. 3.5.5 (a) states to create two 12" x 12" panels each 12 hour shift and send panels to a third party laboratory for testing. Due to the site conditions and tidal activity, getting a 12-hour shift is going to be almost impossible. As stated in the pre-bid meeting and the productivity analysis, the best case scenario would be to get a 4-5 hour working shift. In addition performing these tests at a rate of 2 tests per shift is very expensive, somewhere in the range of $1 million. Hence is it possible to lower this requirement to 1 panel every 6-hour shift.

The specification section will be revised to require 1 panel test every 6-hour shift. However, note that each panel that is made does not need to be tested. See Amendment 0004 for additional information

30 Based on the overall scope of work, site conditions, various trades involved and size of the project, we request an extension to the bid due date by at least 10 days.

See Amendment 0003

31 What is the difference between the Special Inspector and the QC Inspector required for

CFRP testing on this project?

QC Inspector is responsible for activities employed in the detection and measurement of the characteristics of construction materials and methods. This process can include providing recommendations for corrective actions.

Special Inspector is a dedicated person for critical structures or elements (CFRP, Piles, etc.) by individuals having specific expertise and qualification to verify compliance with approved construction documents and referenced standards. These inspections generally pertain to surface preparation, materials, installation, fabrication, erection or placement of components, and connections.

32 TC Series Drawings: Please confirm that the contractor may leave all required traffic control equipment, signage, and lights in place continuously while work is performed in each respective phase.

Correct, the traffic control equipment can be continuously left on the Trestle if it is actively protecting the construction site.

This will need to be closely coordinated with the COR.

33 Drawings S111 to S117: Please clarify what methodology was used to determine the specific box beams which require strengthening. There does not appear to be a discernable pattern. What each box beam inspected or tested to determine a structural deficiency? Does each box beam exhibit signs of structural overload?

The box beams do not exhibit visible signs of overload. Due to poorly fabricated box beams cast around 1993, there was evidence that the existing prestressing steel may be corroded from the inside of the box beam cavity due to improper cover or no concrete confinement. A Ground Penetrating Radar program was instituted that scanned every beam to determine potential loss of prestressing strands. The results of the program were used to identify the box beams that are compromised and need strengthening.

36 The specifications call the for the load test company to access the topside of the box beams to perform the pre-test instrumentation, both before and after CFPR installation. Is the intention for the contractor to remove sections of the trestle slab in order for the load test company to access the topside of the box beams?

Topside of the box beams means the top of deck (roadway and rail surface). Removal of the trestle slab is not required.

37 Please clarify who is required to perform and pay for any removals and later reinstallation of obstructions.

Based on reference drawings and previous inspections, no obstructions are envisioned for installing the CFRP. If by chance an obstruction is encountered, the contractor will notify the COR for further instruction. The contractor does not need to include this in their bid.

38 It appears that paragraph 2.1.2 "Alternate Products" was removed from the specification with one of the amendments. Are alternate products still permitted provided they submit the required information defined in paragraph

SD-03?

See Amendment 0002

39 Are there any sections of the box girders that are exhibiting AAR?

We are not aware of the existence of AAR on the existing box beams.

40 What is the ambient surface moisture content of the existing box girders? Does it exceed 5.0%

The exact moisture content of the existing box beams is unknown.

41 What is the average relatively humidity below the pier?

The humidity level under the pier will fluctuate. The contractor will be required to enclose the work area for containing blast particulate.

Additionally the contractor is expected to control the relative humidity below the allowable level in order to maintain production rates.

42 Section 3.4.2 states that resins cannot be diluted. Can resins be thickened with lightweight fillers? If so, what testing will be need to be submitted to demonstrate the properties of the resin have not been reduced?

If so, will 3,000-hour durability testing need to be submitted for filled-resins?

The manufacturer of the strengthening system will need to determine if field-thickened resins can be used on their system and still meet all of the requirements in

Specification Section 03 25 00. This is a bond critical application and if Cab-O-Sil reduces the bond below those required by the specification it will be rejected.

43 It may be possible that a pull-off test will fail at a high value but not fail in the concrete substrate or may exceed the capacity of the tester. Recommend these not be rejected.

Each circumstance will need to be evaluated if and when this occurs. If testing achieves the targeted 200 psi minimum pull-off strength it will likely be approved

44 If the "Pre-Strengthening" load test reveals the existing box beams possess more capacity than calculated, will the CFRP be eliminated or will the CFRP design be modified to reduce the number of layers?

Currently there are no plans to eliminate or modify the number of CFRP layers based on the load test results. The load test is not intended to be used as a tool to adjust the required strengthening system.

45 If the "Pre-Strengthening" load test reveals the existing box beams possess more capacity than calculated, will the CFRP design be modified to reduce the number of layers prior to performing the "Post-Strengthening" load test?

Currently there are no plans to eliminate or modify the number of CFRP layers based on the load test results. The load test is not intended to be used as a tool to adjust the required strengthening system.

46 The corporate experience requirements in the RFP state that experience of proposed subcontractors will not be considered for meeting the requirements under corporate experience. Please reconsider this restriction. This will preclude contractors from teaming up with potentially the best qualified installers who themselves cannot qualify as general contractors due to the other corporate experience requirements.

At the very least, please consider allowing contractors to enter into teaming agreements, submitting the teaming agreements with their proposals and relying on the installation experience of the best CFRP contractors available. This will surely make for a better project in the end. By not allowing subcontractor's qualifications to be used, the government has effectively shut out a number of highly qualified CFRP contractors who will not be able to participate in the solicitation process.

Please see Amendment 0002.

47 The Special Inspection specifications require that the inspections detailed in the Schedule of Special Inspections at the end of the section (no page numbers) be performed by an independent third party. The Schedule of Special Inspections is broken up into three (3) sections: A. Structural -

Concrete, B. Structural - CRFP and C. Geotechnical. The schedule appears to indicate that a full time special inspector is required onsite for each of the three disciplines while these activities are ongoing. Please confirm that this is the intent.

48 Please consider allowing the use of and adding a section for Cementitious Repair Mortar. With 70% of the total 463 repair areas identified on Drwgs. S-601 through S- 605 being 1 SF or less, it seems logical that a repair mortar would be appropriate for these small repair areas.

Refer to Paragraph 2.3.1 of Section 03 01 30.71. This paragraph outlines the use of a Packaged Cementitious Repair Mortar.

49 This paragraph indicates that embedded anodes are to be installed in all concrete repair areas. Please confirm. The details and notes on Drwg. S511 make no mention of the embedded anodes.

The anode installation requirement is outlined in Concrete Repair Note 9 on Sheet S001.

50 Please confirm that a volumetric mixer can be used for producing the concrete for the project. Specification section 03 37 13 (Shotcrete Repairs) lists ASTM

C685/C685M in section 1.2 under references but it has not been included in the references for specification 03 01 30.71.

Contractor will need to determine if a volumetric mixer is the correct equipment to perform the Concrete Spall Repairs.

51 Under Box Beam Strengthening Notes, note 19 refers to an illustration on the page which does not exist.

Under Note 19 delete "ILLUSTRATED ON THIS SHEET", See Amendment

52 This paragraph indicates the permits that will be obtained by the Government.

Have any of these permits been acquired already? If so, could you provide contractors with copies?

54 This paragraph indicates that all crack repairs need to be completed prior to installation of the CFRP system. There are no details on the quantity or extent of crack repairs or specifications for crack repair.

Please clarify the quantity the contractor should use in preparing their proposal and provide the necessary specifications.

For bidding purposes assume crack injection is not required. The surfaced of the box beams show very little cracking, with most less than 0.01 inches.

55 This section indicates that procedures which should be followed for replacing reinforcing steel which is also reflected on drawing S001 notes. Please indicate the quantity of replaced reinforcing the contractor should use in preparing their proposal.

For the purpose of bidding, assume that the reinforcing does not need to be replaced, but contractor shall be prepared to replace reinforcing if needed. This cost does not need to be included in the bid.

56 Please confirm that pile driving activities can only be performed between November 1 and February 28th or 29th of any year.

57 As per section 3.5.5.c the required acceptance criteria for the submitted CFRP product is defined as a minimum

“tensile strength” exceeding 1120kip/in/ply.

Please confirm that this should in fact be defined as a minimum “stiffness” as defined by the ASTM testing.

Tensile "strength" should be tensile "stiffness." This section will be revised in Amendment 0004

58 Please verify that the ASTM D7565/D7565M test results shall be the basis of contractual acceptance of the submitted CFRP systems.

This section will be revised,see Amendment 0004. Tension testing shall performed in accordance with ASTM D7565 and/or ASTM D3039

59 Please verify that an allowable stress analysis has been performed and that the allowable concrete compression stresses are not exceeded.

Yes, the appropriate calculations have been performed

60 With reference to the section details shown on S504… Is there a design guideline or reference available for the one-sided shear strengthening of the stems/webs of the box girders? Has a strain analysis has been performed on the section? Given the amount of fiber added to the girder, the debonding strains seem to be relatively low, indicating that care should be taken to allow for proper yielding of the steel at the limit state of the girder. Please verify that the required stamped submittals as per section 1.3.SD-

05 are only relevant to the stiffness per inch width as determined by the ASTM D7565/D7565M testing and that the AASHTO FRP

Design Guide and the ACI 440.2R are not relevant. If these design guidelines are to be considered relevant please provide the required increase in capacity for the referenced box beams so they form part of the stamped submittal.

Stamped and sealed drawings are only required for the calculations that show the selected product meets the minimum cured CFRP stiffness (EA) identified in the Contract Documents

61 A)Can any fixed platforms, hanging platforms or scaffolding be affixed to the pier to perform the work.?

B) If platforms can be affixed, are there any restrictions on the locations, bearings, connections etc.?

A properly designed platform may be hung under the pier by affixing it to the existing structure. It was envisioned that the existing bent caps can be used to support the fixed platform supports. Contractor is not permitted to drill and anchor into the existing box beams. Since a fixed plaform is most likely the most effecient method, other temporary support alternatives will be considered.

62 Can you provide the required EA on the drawings for each box rather than the ones that correspond to 1, 2, or 3 layers of the

Structural Technologies product?

See Amendment 0004 for revised values.

63 We are unable to locate the design bearing capacity for the new piles. Please clarify.

Refer to the top left corner of Sheet S001 under heading "Foundation"

64 The pre-construction sequence notes indicate that these activities (Phases 1-3) are to be completed within 120 days after contract award. Please consider removing this restriction. If the government takes the full period available before awarding the project, award would not occur until

11/23/18. Allowing 60 days for submittal submissions, review and approvals means the soonest we could be onsite would be 1/23/18 which does not take into account any required procurement lead time. This would likely be the worst time of year to be attempting to perform inspections, load tests or mockups onsite and the schedule constraint would require that these three phases (1-3) be completed by 3/23/19.

Given that the contractor will be required to have an approved baseline schedule before mobilizing, wouldn't it be simpler to allow that schedule to drive the completion of these activities?

65 The pre-construction sequence notes indicate that the CFRP mockup occurs in

Phase 1 and before the inspection windows occur. The Preliminary Schedule attached to the RFP for reference only and submitted by the A/E shows the CFRP mockup occuring after the inspection windows have been completed. Please clarify the owner's suggested or required scheduling sequence.

67 Specification section 03 25 00 “Externally Bonded CFRP Fabric Systems” states that the Contractor is to “inject all cracks in the surface of the concrete or the substrate wider than 0.01 in. with epoxy resin under pressure … prior to installation of the CFRP system.” Since information regarding surface cracks is not shown on the contract documents, what quantity of epoxy injection crack repair should the Contractor assume is required for bidding purposes?

(End of Summary of Changes)