FDOT Standard Plans Index 400-090: Approach Slabs (Flexible Pavement Approaches)

Design Criteria

Design Criteria AASHTO LRFD Bridge Design Specifications ; Structures Design Guidelines ( SDG ) ; Structures Detailing Manual ( SDM ) .

Design Assumptions and Limitations

Design Assumptions and Limitations Index 400 - 090 is intended to be used with asphalt (flexible) roadway approach pavement. Approach Slabs are intended to provide a smooth vertical transition between the roadway approach pavement and the bridge. They are supported at the bridge end by the end bent and by the embankment at the roadway approach end.

This support configuration all ows the Approach Slabs to rotate and settle as the roadway approach embankment settles. No additional supports (piles, footings, etc.) are required or allowed. See SDG 3.1 for distribution of design loads from the approach slab to the end bent.

The details of the approach slab adjacent to the end bent backwall as shown on the standard are intended for use with Poured Joint with Backer Rod and Strip Seal Expansion Joints. If other expansion joint types are used, e.g. finger or modular expansion jo ints, modifications to the standard may be required to accommodate the expansion joints and the blockouts used to install them.

Payment

Payment Item number Item Description Unit Measure 400 - 2 - 10 Concrete Class II, Approach Slabs CY 415 - 1 - 9 Reinforcing Steel - Approach Slabs LB 400 - 7 Grooving (See Sheet 1 Note 1) SY

What your plans must show

Plan Content Requirements for this index — the SPI's checklist for designers.

• - 090 requires supplemental sheets, a completed data table and reinforcing bar lists to be included in the Structures Plans. Some roadway elements may need to be carried onto the approach slab, and in these cases special attention must be given to clarifying in the plans which elements are to be included as part of the roadway. In the Roadway Plans: Include details and payment for the optional base under the approach slab. The minimum structural requirement under the approach slab is Optional Base Group
• 2. If the optional base group for the roadway approaches is Group 2 or better, the same base group may be continued under the approach slab. Include embankment , optional base and stabilization as required for the area of the approach slab in the roadway quantities. The asphalt overlay should be 1 ¾” thick and continuous with the roadway asphalt pavement. Include the required pavement type along with the structural and friction course thicknesses. Past recommendations for asphalt overlay thickness are as follows:
• Standard Plan s Instructions Topic No. 625
• - 090 Approach Slabs (Flexible Pavement Approaches) FC
• - 5: final structural course of 1" and a friction course of 0.75 ” FC 9.5: final structural course of 0.75" and a friction course of 1.0"FC
• - 12.5: overlay the approach slab with one layer of friction course 1.75" thick. In the Structures Plans: Include supplemental sheets showing as a minimum a Plan View with geometry and pertinent information not covered by this standard e.g., Survey Lines, PGL, Direction of Stationing, Phase Construction Joints, Raised Sidewalks and any other information necess ary to accurately complete detailing of the Approach Slabs. Label Approach Slab by name or Index number. Match the skew angle of the bridge at both ends of the Approach Slab. Urban roadway approaches usually have a 6
• - 0" long unless higher TL
• - 6 barrier is required in which case the designer to determine the correct bar size. Complete the following "Approach Slab Table of Dimensions" and include it on the supplemental sheets. See Introduction I.3 for more information regarding use of Data Tables.
• Standard Plan s Instructions Topic No. 625
• - 090 Approach Slabs (Flexible Pavement Approaches)