Caltrans Office Engineer

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Inquiry #1: Per section 39-1.01 of the Special Conditions it states: "Produce and place HMA type A under the Standard construction process. Do not use vibratory roller for compaction." Is it the States intent to waive the compaction requirements and penalties associated with low compaction per the standard process as a result of eliminating the use of vibratory rollers to obtain compaction? Or is it the States intent to eliminate the use of vibratory rollers for A.C. compaction when the existing water line is within 1 foot from the bottom of AB like it is stated in Section 26 "Aggregate Bases."
Inquiry submitted 04/01/2013

Response #1:4/2/13: Your inquiry has been received and is being reviewed. Thank you for your patience.
Response posted 04/02/2013


Response #2:4/4/13: Please refer to Addendum Number 1. The information is posted at http://www.dot.ca.gov/hq/esc/oe/project_ads_addenda/02/02-4E3404/ad1/02-4E3404ad1.pdf
Response posted 04/04/2013




Inquiry #2: Question #1
Division V, Page 41 of 95 Section 39-1.03E in the Job Mix Formula Verification section it states: “Use the OBC specified on your Contractor Hot Mix Asphalt Data form. No adjustments to asphalt binder content are allowed. Based on your testing and production experience, you may submit an adjusted gradation TV on a Contractor Job mix Formula Proposal form before verification testing”

This requirement is new to Section 39 which historically has allowed the contractor to adjust the plant to ensure field produced material would possess similar properties (asphalt content, gradation, VMA, etc.) and performance to that specified in the mix design. Restricting the contractors ability to account for differences between field plant settings and laboratory measured properties will limit their ability to be able to produce a mixture that meets the mix design properties outlined in the Contractor Hot Mix Asphalt Data form. The March 11, 2013 Project Special Provisions allow the contractor to submit adjusted gradation TV’s that are within the TV limits specified in the aggregate gradation tables prior to a verification attempt. Permitting the contractor to adjust the gradation TV’s may help correct for aggregate breakdown during production but will not mitigate the situation where the there is a difference between laboratory measured asphalt binder content as compared to the plant asphalt binder set point. The inability to adjust the plant asphalt binder set point to produce HMA with laboratory measured asphalt contents that fall within the specified tolerances will lead to failed verification tests.

Will Caltrans remove the limitations related to plant asphalt binder set point settings from Section 39-1.03E of the Special Provisions? If no, will Caltrans allow the contractor to adjust the plant asphalt content setting from that specified in the Contractor Hot Mix Asphalt Data form if as part of the initial verification test, it is determined that the contractor is unable produce material in the field that meets the project requirements (due to low air voids, low VMA, and/or low stability as compared to the original mix design) when the measured ignition oven asphalt content is not at the mix design target oil content? If no, how will Caltrans address the situation where the contractor is unable to verify the JMF resulting directly from the contractors inability to account for the differences between field plant settings and laboratory measured asphalt content by adjusting the plant asphalt binder set point?

Inquiry submitted 04/04/2013

Response #1: 4/4/13: Your inquiry is under review. Please note that due to the current time frame between the inquiry submittal and the bid opening date, a response may not be provided before the bid opening. If a response is not provided before the bid opening addressing your concern, please bid per the current contract documents. Thank you for your patience.
Response posted 04/04/2013


Response #2:4/4/13: Please bid per the current contract documents.
Response posted 04/04/2013




Inquiry #3: Division V, Page 43 of 95 Section 39-1.08A in the Job Mix Formula Verification section it states: “During production, asphalt binder set point for HMA Type A, HMA Type B, HMTA Type C and RHMA-G must be the OBC specified in the Contractor Hot Mix Asphalt Data form”

This requirement is new to Section 39 which historically has allowed the contractor to adjust the plant to ensure field produced material would possess similar properties (asphalt content, gradation, VMA, etc.) and performance to that specified in the mix design. Restricting the contractors ability to account for differences between field plant settings and laboratory measured properties will limit their ability to be able to produce a mixture that meets the mix design properties outlined in the Contractor Hot Mix Asphalt Data form. This contract specifies that HMA be produced and placed using the Quality Control/ Quality Assurance specification which determines acceptance and payment using a statistical based percent within limit specification. For this type of acceptance specification, it is imperative that the contractor produce HMA with laboratory measured properties that are centered within the specification tolerances for gradation and asphalt content. The March 11, 2013 Special Provisions does not allow the contractor to adjust the plant asphalt binder set point to account for differences between field plant settings and laboratory measured properties as relates to asphalt binder content.

Will Caltrans allow the Contractor to adjust the plant asphalt binder set point to account for differences between field settings and laboratory measured properties to produce a mixture with a laboratory measured asphalt content that is at the OBC target? If no, how will Caltrans address the situation where the contractor is unable to produce material that meets the specification requirements and/or limits the contractors ability to achieve a material related bonus associated with the QC/QA specification resulting directly from the contractors inability to account for the differences between field plant settings and laboratory measured asphalt content by adjusting the plant asphalt binder set point?

Inquiry submitted 04/04/2013

Response #1: 4/4/13: Your inquiry is under review. Please note that due to the current time frame between the inquiry submittal and the bid opening date, a response may not be provided before the bid opening. If a response is not provided before the bid opening addressing your concern, please bid per the current contract documents. Thank you for your patience.
Response posted 04/04/2013


Response #2:4/4/13: Please bid per the current contract documents.
Response posted 04/04/2013




Inquiry #4: Division V, Page 39 of 95 Section 39-1.03B in the Hot Mix Asphalt Mix Design section requires the specified Type A ¾” HMA mixture to meet a minimum dry tensile strength of 120 psi. The specification also requires the HMA mixture to incorporate a PG 64-28PM binder in the asphalt mixture. Historical dry tensile strength data for mixes containing a PG 64-28PM binder indicates that a dry tensile strength of 120 psi is not achievable. This information is based on the use modified binders in the State of Nevada over a number of years and the recognized influence of asphalt binder grade on achievable dry tensile strength. Recognizing the limitation on dry tensile strength in mixtures containing modified binders, the Nevada Department of Transportation has established a minimum dry tensile strength requirement of 65 psi min.

If it is determined that a minimum 120 psi dry tensile strength is unachievable with the specified PG 64-28PM binder will Caltrans waive this requirement by way of a no-cost change order?

Inquiry submitted 04/04/2013

Response #1: 4/4/13: Your inquiry is under review. Please note that due to the current time frame between the inquiry submittal and the bid opening date, a response may not be provided before the bid opening. If a response is not provided before the bid opening addressing your concern, please bid per the current contract documents. Thank you for your patience.
Response posted 04/04/2013


Response #2:4/12/13: Please refer to Addendum Number 3 . The information is posted at http://www.dot.ca.gov/hq/esc/oe/project_ads_addenda/02/02-4E3404/Ad3/
Response posted 04/12/2013




Inquiry #5: Division V, Page 43 of 95 Section 39-1.08A in the Job Mix Formula Verification section it states: “During production, asphalt binder set point for HMA Type A, HMA Type B, HMTA Type C and RHMA-G must be the OBC specified in the Contractor Hot Mix Asphalt Data form”

This requirement is new to Section 39 which historically has allowed the contractor to adjust the plant to ensure field produced material would possess similar properties (asphalt content, gradation, VMA, etc.) and performance to that specified in the mix design. Restricting the contractors ability to account for differences between field plant settings and laboratory measured properties will limit their ability to be able to produce a mixture that meets the mix design properties outlined in the Contractor Hot Mix Asphalt Data form. The March 11, 2013 Special Provisions does not allow the contractor to adjust the plant asphalt binder set point to account for differences between field plant settings and laboratory measured properties as relates to asphalt binder content.

Will Caltrans allow the Contractor to adjust the plant asphalt binder set point to account for differences between field settings and laboratory measured properties to produce a mixture with a laboratory measured asphalt content that is at the OBC target? If no, how will Caltrans address the situation where the contractor is unable to produce material that meets the specification requirements resulting directly from the contractors inability to account for the differences between field plant settings and laboratory measured asphalt content by adjusting the plant asphalt binder set point?

Inquiry submitted 04/08/2013

Response #1:4/8/13: Your inquiry has been received and is being reviewed. Thank you for your patience.
Response posted 04/08/2013


Response #2:4/16/13: Please bid per the current contract documents.
Response posted 04/16/2013






The information provided in the responses to bidder inquiries is not a waiver of Section 2-1.03, “Examination of Plans, Specifications, Contract, and Site of Work,” of the Standard Specifications or any other provision of the contract, nor to excuse the contractor from full compliance with the contract. Bidders are cautioned that subsequent responses or contract addenda may change a previous response.