FHWA Resource Center
STRUCTURES TEAM
Prestressed Concrete Committee for Economic Fabrication (PCEF)
MID- ATLANTIC STATES PRESTRESSED CONCRETE
COMMITTEE FOR ECOCONOMIC
FABRICATION MEETING
AUGUST 29, 2006
DISTRICT 7-BUCKEYSTOWN, MD
Participants:
Ahmed Mongi (WVDOT), Ed Barton (WVDOT), Ben Beermen (WVDOT),
Bill Via (VDOT), Serge Ter-Arakelov (PennDOT), Paul Ingram (PennDOT),
Tim Shaw (Site-Blauvelt Engineers-TRC), Joe Ryan (MDSHA),
Joseph Navarra (MDSHA), Barry Benton (DelDOT), Waseem Fazal (DelDOT),
Richard Livingston (FHWA-HRDI), Hank Bonsledt (PCAP), Celik Ozyildirim (VTRC-VDOT), Sylvester Okpala (DCDOT), Lou Triandafilou, (FHWA).
1. Introduction
Mr. Lou Triandafilou of the FHWA convened the meeting. He welcomed all participants. The participants introduced themselves. A copy of the current mailing list and subcommittee list was circulated among the attendees for verification of information and making necessary corrections.
2. Approval of minutes from February 6, 2003 meeting.
Delaware made a motion, seconded by Pennsylvania, for approval of the minutes from the last PCEF meeting, February 6, 2006. The members approved the minutes of meeting with no change.
3. Update on activities of Central Atlantic Bridges Associates (CABA) by Hank Bonstedt, PCAP.
Mr. Hank Bonstedt presented the overall goal and vision behind the establishment of the Central Atlantic Bridge Associates (CABA). He stated the prime purpose was to interface with different groups in technical committees, including prestressed concrete manufacturers, DOTs and other agencies. This group has formed to promote prestressed concrete, to be involved in standards/specification development, and to provide a liaison between agencies and member prestressed concrete manufacturers. He also stated that this group is affiliated with PCI (Chicago office) in a role as regional partner. He stated that to become a member of this group, the manufacturer’s plant has to be PCI- certified. Annual membership fee was $6,500.
Hank outlined the different services being offered on their web site. He offered a PCEF forum on the CABA website to post PCEF proceedings, minutes of meeting, presentations, member contacts and others.
He also stated that CABA is offering a one-day training class for DOTs on prestressed concrete bridge design, based on the LRFD design code, with practical examples using the PCI Bridge Design Manual. He asked States DOT representatives to take advantage of this opportunity by contacting him to host this training class. He said the class would cost between $120.00 to $180.00 per registration based on facility available/ offered, plus $300 for the manual.
Hank also noted that at this time there are six prestressed concrete producers who are official members of that group, including Schuylkill Products, Bayshore Concrete, New Enterprise, Precast System, Atlantic Metrocast and Jersey Precast. He is speaking with Rockingham Precast about the possibility of joining. He stated that non- member manufacturers could also provide their input in technical committees for different standards and specifications.
4. Design parameters & standardizations sub committee
Mr. Claude Napier and Mr. John Martin were not present at the meeting; hence Mr. Lou Triandafilou informed the attendees that work is in progress for making a CD-ROM with a list of all Bulb-T sections with complete guide and history. Mr. Bonstedt stated that some local DOTs were interested in modifying the standard Bulb-T sections. He stated that PennDOT has made some adjustments in top flange width, and will be incorporating the shapes into their computer software programs. He also stated that NYSDOT has adopted 9-12 different beam shapes of the Bulb-T. Lou asked that DOTs inform the subcommittee of adaptations of particular beam shapes from the standards.
5. Presentation on Bridge Construction projects using performance related specification (PRS), by Dr. Celik Ozyildirim, Virginia Transportation Research Council (VTRC) – see attachment
Dr. Celik Ozyildirim of VTRC, presented VDOT’s efforts in moving towards performance-related specifications; their goal, implementation plan and pilot projects. He informed the committee that the specification is based on Percent Within Limits - QA/QC guidelines with incentive and disincentives, with pay factors for acceptance testing of hardened concrete strength and permeability. He informed the group that the whole emphasis is to improve the QC program and consistency of plant production for ready- mix concrete producers. He stated that at this time the pay factors, QL and QU, are dependent upon average and standard deviation of the lot only. The number of samples (n) may increase for a larger project. He told the committee they are very confident that, by adopting this specification, they will improve upon overall concrete quality.
6. Materials & Construction QC/QA subcommittee (minutes attached)
In the absence of Mr. Bob Horwhat and Mr. Paul Finnerty, Mr. Serge Ter-Arakelov informed the committee participants that the matrix of self- consolidating concrete (SCC) has been finalized. The document was prepared with input from the agencies and industry, is well rounded, and covers all major processes and steps to achieve good quality for prestressed concrete structures.
PA noted 1 prestressed concrete plant was using SCC and achieving good finishes, except for some minor flaking along the bottom flanges. Mix proportions and placement procedures are keys to success, along with allowing minimal vibration. VA has noted some foaming on the surface and inconsistencies with aggregate grading, leading to loss of mix stability and air void system. They are looking at viscosity-modifying admixtures and fine aggregate proportions.
Voting on Ballot Item 201A-2006, Quality Control Requirements, as an appendix to the previously-approved materials specification guidelines for precast /prestressed concrete products, occurred and the document was unanimously approved. DE, WV, and DC sent votes back. MD, VA & PA also agreed to the proposal along with other participants of the meeting, hence this document is adopted as an “Appendix” of specification guidelines for precast/ prestressed concrete products. Serge also stated that the subcommittee is developing similar documents for precast structures, as a part of a joint effort of standardizing requirement for all agencies.
7,8. Update by Each state DOT representative on HPC project/ specification implementation & PCEF Bulb –T, implementation since August 2005.
VA- HPC specification consists of low permeability requirements, since they use pozzolanic materials that help to achieve low coulomb readings and retard ASR. VADOT continues their full implementation of HPC as reported last year. They have also achieved cost savings by using PCEF Bulb-T beam construction (see attachments). VADOT plans to have a lightweight SCC beam fabricated at Bayshore Concrete Products plant, using ¾” saturated lightweight aggregate. Properties such as unit weight and modulus of elasticity will be evaluated, along with mixing and curing temperatures.
WV- HPC specification (low permeability) has been used in all bridge decks, in the I-64 segmental concrete bridge, and in the mass concrete (SCC) of the Blennerhassett Island bridge foundations. No progress to report for Bulb-T beam implementation since last year.
DE- Has 2000- coulomb requirement for deck permeability; 28-day strength is still 4500 psi; ACI surface evaporation chart limits; and a requirement for 7-day continuous wet curing. They use slag in their mixes to achieve HPC properties and retard ASR. DelDOT has a couple of PCEF bulb-T projects under design. They are also tracking the pooled-fund research study headed by Kansas State University, on Low-Crack HPC bridge decks. Delaware, along with many western states, is contributing funding towards that research.
The concepts they are pursuing include: less cement content (around 520 lbs/ cu-yd), less admixtures, optimization of aggregates, larger nominal aggregates sizes, slightly higher air contents (8%), 14-day continuous wet curing. Mixes are showing good resistance to early- age cracking.
PA- HPC special provision exists with low permeability requirement. Research conducted with 10 mix designs on I-99. They are emphasizing the need for 14-day continuing wet curing and lower cementitious materials quantities (564 pounds) to achieve HPC properties. Plants are required to qualify their mixes at 6000-6500 psi maximum 28-day strengths. Also looking at ternary mixes. Most bridge deck concrete is now HPC. They stated that the PCEF Bulb-T details have been added to their standard designs and computer programs for implementation. Have built 1 bridge with PCEF beams, but have no cost comparisons at this time.
MD- HPC for MDSHA is higher cement content and lower w/c with permeability requirement and has no issue. Also use slag and silica fume in beams. MDSHA is working on one PCEF Bulb –T project that will be advertised for a Route 313 bridge on the Eastern Shore in October 2006. This is a single span bridge project with semi-integral abutment. There are also several PCEF beam bridges with steel diaphragms to be built on the Route 30 by-pass project, which is a design/build.
DC- They use 6000 psi HPC for overlays projects and are very satisfied with the results. No projects under design yet using PCEF Bulb T- beams. Most of their bridges are short span steel superstructures.
9- Update by PennDOT representatives on action taken as a result of P/S concrete adjacent box beam bridge collapse and results of AASHTO survey.
Serge reported that their investigation is still underway and scheduled to be completed by the end of the summer. Early conclusions are that there are multiple reasons for the failure. This bridge was 46 years old. PennDOT completed a survey of conditions of other similar box beam bridges, resulting in replacement of 32 bridges. They are starting further advanced investigation on the remaining 801 similar non-composite bridges.
10- Other issues
Mr. Richard Livingston presented information on a pooled fund solicitation for the field survey of bridges for Delayed Ettringite Formation (DEF), and their related damages on concrete bridges. Their objective is to develop a data base, characterize different concrete samples for bridge decks, and analyze non-destructive methods. These tests must be run by one lab, in order to do a statistical analysis and evaluate how this DEF affects our bridge decks. He encourages committee members to visit web site for more information.
Lou presented information (attached) on accelerated bridge construction projects completed successfully and talked about the benefits of using prefabricated bridge elements and systems to achieve this concept.
In response to a question outside the region on texturing bridge decks, none of the States present reported using longitudinal grooving.
In response to another question outside the region on tall pier design and tall elastomeric bearing design for a mult-span continuous welded steel girder bridge, the States were asked to provide feedback on the following questions:
a) Provide references used on tall pier design (70’ minimum), particularly with regard to wind load gradients, recommendations for construction joint spacing and bracing spacing, etc.
b) Recommended height limit on laminated elastomeric bearings
c) Tallest elastomeric bearing in service
d) Problems/long-term performance associated with the tall bearings
e) Type of side retainers/restrainers for tall elastomeric bearings (on normal, skewed, curved bridges)
f) Stability problems experienced during steel erection or in-service where the abutment has a PTFE bearing and the adjacent tall pier has a laminated elastomeric bearing
g) When an inner core is used to limit PTFE pad movement
Lou confirmed that the next PCEF meeting will be held on Monday afternoon, February
05, 2007, in Atlantic City, NJ, in conjunction with Mid Atlantic States Quality Assurance Workshop. He also offered the FHWA Resource Center office in Baltimore for hosting future PCEF meetings, and asked for other DOT volunteers to host these meetings. He said any future place should be convenient to all. With traveling constraints enforced in some agencies, a central location would help participation. Video- or teleconference facilities would also help those unable to travel.
11- Adjournment at 12:40 p.m.
TRAINING
What's New
