25-05-2012, 12:59 PM
STRUCTURES DESIGN GUIDELINES
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1 GENERAL REQUIREMENTS
1.1 GENERAL
This Chapter clarifies, supplements, and contains deviations from the information in LRFD Sections [2], [5], and [6]. These combined requirements establish material selection criteria for durability to meet the 75-year design life requirement established by the Department.
ENVIRONMENTAL CLASSIFICATIONS
General
A.The District Materials Engineer or the Department's Environmental/Geotechnical Consultant will determine the environmental classifications for all new bridge sites. Environmental classification is required for major widenings (see definitions in SDG Chapter 7) and may be required for minor widenings. This determination will be made before or during the development of the Bridge Development Report (BDR)/30% Plans Stage (See the PPM Volume 1 Chapter 26) and the results will be included in the documents. The bridge site will be tested, and separate classifications will be determined for both superstructure and substructure.
B.In the bridge plans "General Notes," include the environmental classification for both the superstructure and substructure according to the following classifications:
CONCRETE AND ENVIRONMENT
General (Rev. 01/11)
A.Assume the use of Florida limerock coarse aggregate in design, with K1= 0.9 as the correction factor when calculating the Modulus of Elasticity in LRFD [5.4.2.4]. For Florida limerock, wc is typically taken as 0.145 kcf.
B.In LRFD [5.4.2.6] under "For normal-weight concrete:", in the second bullet, replace the modulus of rupture of 0.37f’c with 0.24f'c.
Commentary: FDOT has chosen to use the traditional modulus of rupture that has been
in the AASHTO specifications since the 1960's.
C. Use ASTM A615, Grade 60 reinforcing steel for concrete design.
D.Do not specify epoxy coated reinforcing steel.
E.The use of lightweight concrete for structural applications requires prior SDO approval.
EXISTING HAZARDOUS MATERIAL
A.Survey the project to determine if an existing structure contains hazardous materials such as lead-based paint, asbestos-graphite bearing pads, other asbestos-containing materials, etc. Information will be provided by the Department or by site testing to make this determination. Coordinate with the District Asbestos Coordinator for issues relating to asbestos-containing materials.
B.When an existing structure has been identified as having hazardous material, develop adequate abatement plans and provisions for worker safety, handling, storage, shipping, and disposal of the hazardous material. If proposed work will disturb identified hazardous materials, include in the project documents, protection, handling, and disposal requirements.
C.When a project involves hazardous materials, the FDOT design project manager will provide assistance in preparing the construction documents and the technical special provisions for handling and disposal of hazardous materials. Use the National Institute of Building Sciences (NIBS) Model Guide Specifications for Asbestos Abatement and Management in Buildings when developing asbestos abatement plans.
D.Comply with the General Industry, Construction and Worker Safety regulations of the Occupational Safety and Health Administration (OSHA) and the Environmental Protection Agency (EPA) for the handling and disposal of hazardous materials.
1.6 ADHESIVE ANCHOR SYSTEMS
1.6.1 General (Rev. 01/11)
A.Adhesive Anchor Systems (adhesive bonding material and steel bar anchors installed in clean, dry holes drilled in hardened concrete) are used to attach new construction to existing concrete structures. Anchors may be reinforcing bars or threaded rods depending upon the application.
B.For pre-approved Adhesive Anchor Systems, refer to the Department's Qualified Products List (QPL), Adhesive Bonding Material Systems for Structural Applications. Comply with Section 937 of the Specifications. Require that Adhesive Anchors be installed in accordance with manufacturer's recommendations for hole diameter and hole cleaning technique and meet the requirements of Section 416 of the Specifications.
Commentary: Installation of Adhesive Anchor Systems in saturated, surface-dry holes;
i.e., holes with damp surfaces but with no standing water, is not pre-approved or
recommended by the Department. However, in the event such a condition is
encountered during construction, the Department may consider approving continued
installation, but only on an adjusted, case-by-case basis. The damp hole strength of
products on the QPL has been determined to be approximately 75% of the required
dry hole strength.