CONCRETE BARRIERS, TRAFFIC RAILING S, AND PARAPETS
521-1 Description.
Construct precast or cast in place concrete barriers, traffic railings, opaque visual barriers, and parapets, herein referred to as rigid barrier, in accordance with the Standard Plans and the details shown in the Plans. Use stationary removable forms or sliding forms to construct the rigid barrier. Do not use permanent precast concrete rigid barrier on bridge or box culvert structures. Submit written certification from t he manufacturer of the precast rigid barrier that the barrier meets the requirements of this Section. Rigid barrier is produced using certification acceptance; therefore, assume responsibility for performance of quality control testing and inspections requ ired by Sections 346 and 400. Perform all Quality Control Testing and inspections using CTQP qualified testing personnel. Perform compressive strength testing in a laboratory inspected by CCRL or CMEC. Ensure that each shipment of products to the job site includes a list of products shipped and the required written certification statement for each product. Submit this list and certifications to the Engineer.
521-2 Materials.
Meet the following requirements: Flowable Fill ................................ ....................... Section 121 Concrete ................................ .............. Sections 346 and 347 Reinforcing Steel ................................ ................ Section 415 Joint Materials ................................ ........................... 932-1.1 Joint Materials* ................................ ..... 932-1.2 and 932 -1.3 Barrier Delineators * ................................ ......... Sections 705 *Use products listed on the Department’s Approved Product List (APL).
521-3 Precast Temporary Concrete Barrier.
Meet the requirements of 102 -9.5.
521-4 Construction.
521-4.1 General: The Contractor may use stationary removable forms or slip form
construction methods provided a completed rigid barrier with acceptable alignment and finish is obtained. Do not use forms which a re damaged or are not in alignment. At no expense to the Department, remove and replace sections of rigid barrier having unconsolidated concrete, surface blemishes, deviations in alignment or profile which exceed tolerances, or other defects which cannot be repaired to the satisfaction of the Engineer.
521-4.2 Stationary Form Construction: Provide precast or cast in place concrete rigid
barrier constructed using stationary forms in accordance with Section 400 and provid e a general surface finish. Align and erect the stationary form so that all plane surfaces of the finished barrier will have no deviation greater than 3/8 inch measured as an ordinate between the concrete and a 10 foot straightedge. Correct all alignment deviations greater than 3/8 inch. Stra ightedge by half lapping the straightedge for the full length of all plane surfaces.
521-4.3 Slip Form Construction: When electing to use the slip form method in lieu of
the stationary forming method, place the concrete with a slip form machine approved b y the FY 2023-24 Return to Table of Contents Engineer. The concrete cover tolerance is plus or minus 3/4 inches from the plan dimensions, except the minimum concrete cover, as constructed, must not be less than 1 -3/4 inches. Provide a finished texture to the slip formed rigid barrier by hand troweling, brushing, or both to eliminate pockmarks, blemishes and any other discontinuities in surface texture. Ensure that the final finish has a fine texture and is free of pinholes, pockmarks, and blemishes. Remove and recast or repair sections of sl ip formed rigid barrier having areas of unconsolidated concrete, having surface blemishes, and/or having pockmarks greater than 1/2 inch in diameter after hand troweling and brushing. Repair areas of unsatisfactory surface finish by hand methods using mort ar screened from the concrete used to construct the rigid barrier. Use the mortar screened from the rigid barrier concrete only to fill holes and surface blemishes below the slip formed surface of the concrete. Do not use mortar as a surface overlay coating on the rigid barrier concrete. During the finishing operation, while the concrete remains plastic, straighted ge all plane surfaces of the slip formed rigid barrier with a 10 foot straightedge. Straightedge by half lapping the straightedge for the full length of the plane surfaces. Correct any deviation found during straightedging, greater than 3/8 inch, measured as an ordinate between the concrete surface and the straightedge, in an approved manner at no expense to the Department. Do not use surface overlay coatings of mortar screened from the concrete, or surface overlay coatings of concrete to correct alignment deviations.
521-5 Curing.
Meet the requirements of Section 400.
521-6 Joints.
521-6.1 General : Place expansion and contraction joints in concrete rigid barrier either
mounted on or adjoining rigid structures in a manner similar to the type and method of jointing used in the supporting or adjoining structure or as shown in the Contract Documents. Place expansion and contraction joints in concrete rigid barrier supported by soil or flexible foundation materials in the manner detailed in the Plans.
521-6.2 Contraction Joints in Rigid Barrier Supported by or Adjoining Rigid
Structures : The Contractor may form or saw contraction joints. When sawing contraction joints , saw them as soon as the concrete has hardened sufficiently to permit sawing without raveling and before uncontrolled cracking occurs, but in no case later than 12 hours after casting. Match contraction joints to adjacent contraction joints in the structu re. Space contraction joints at 15 to 30 foot intervals. For rigid barrier on bridge structures or approach slabs, space contraction joints as shown in the Contract Documents.
521-6.3 Expansion Joints in Rigid Barrier Supported by or Adjoining Rigid
Structures: Construct expansion joints at right angles to the face, and extend them through the entire cross -section of the rigid barrier . Construct expansion joints at the same location and width as the expansion joints in the structure on which the rigid barrier rests and at other locations shown in the Contract Documents. Form expansion joints with an expansion filler material or removable forming materials and secure to the forms as required to provide proper position.
521-7 Repairs and Rejection.
For perma nent precast concrete rigid barrier that has not been installed, e valuate cracks, spalls and other deficiencies in accordance with 450 -12. Repair deficiencies in accordance with FY 2023-24 Return to Table of Contents
450-13 or the plant’s approved repair methods that are included as part of the Quality Control
(QC) Plan. Ensure that the original performance and durability of the repaired rigid barrier is maintained. Use materials for concrete repair that will meet or exceed the strength requirement for the class of concrete used. Materials meeti ng the requirements of Section 930 may be substituted for non -shrink grout when required by 450 -13. Concrete rigid barrier is subject to rejection if it fails to conform to any of the Specification requirements after repair. The disposition of concrete cracks in rigid barrier after installation shall be in accordance with 400 - 21.
521-8 Method of Measurement.
The quantity to be paid for under this Section will be the plan quantity, in feet, completed and accepted. The quantit y will be measured along the centerline of the rigid barrier from begin to end station, including transitional and end sections, with no deduction for expansion joints , open joints , or leave-outs.
521-9 Basis of Payment.
Price and payment will be full com pensation for all work specified in this Section, including all reinforcing, concrete, flowable fill, soil stabilization, miscellaneous materials, and incidentals necessary to complete the work. Payment will be made under: Item No. 521 - 1- Median Concret e Barrier - per foot. Item No. 521 - 5- Concrete Traffic Railing - Bridge - per foot. Item No. 521 - 6- Concrete Parapet - per foot. Item No. 521 - 8- Concrete Barrier - with Junction Slab - per foot. Item No. 521 - 9- Opaque Visual Barrier - per foot. Item No. 521 - 72- Shoulder Concrete Barrier - per foot. FY 2023-24 Return to Table of Contents SECTION 522 CONCRETE SIDEWALK S AND DRIVEWAYS
522-1 Description.
Construct concrete sidewalks and driveways in accordance with the Plans and the Standard Plans. Sidewalk will include curb ramps, landings, transition slopes, sidewalk curb, and edge beams.
522-2 Materials.
Meet the requirements specified in 520 -2 and the embankment utilization requirements of Standard Plans Index 120 -001.
522-3 Forms.
Provide forms as specified in 520 -3.
522-4 Foundation.
Shape and compact the foundation materials with suitable equipment to a firm, even surface, true to grade and cross -slope. Meet the testing frequency and maximum lift thickness requirements of Section 120. Record density test results in the Earthwork Records System (ERS) section of the Department’s database. Compact cut-and-fill areas within 1 foot beyond each side of the sidewalk or driveway , when right -of-way conditions allow . Compact the foundation material below the bottom of concrete for a minimum depth of 1 foot for cut areas, 1 foot for fill areas less than 1 foot, and 2 feet for all other fill areas to a density not less than 95% of the maximum density as determined by FM 1-T099. Compact the material in the remaining fill areas to match the adjacent area density.
522-5 Joints.
Install expansion and contraction joints in accordance with the Plans and the Standard Plans.
522-6 Placing Concrete.
Place the concrete as specified in 520 -5.
522-7 Finishing.
522-7.1 Screeding: Strike-off the concrete by means of a wood or metal screed, used
perpendicular to the forms, to obtain the required grade and remove surplus water and laitance.
522-7.2 Surface Requirements: Imprint concrete as detailed in the Plans, otherwise
provide a broom finish. Ensure that the surface variations are not more than 1/4 inch under a 10-foot straightedge or more than 1/8 inch on a 5 -foot transverse section. Finish the outer edges of the concrete with an edging tool having a radius of 1/2 inch.
522-7.3 Sidewalk Cross Slope Requirements: Construct sidewalk with cross slope as
shown in the Plans and Standard Plans. Sidewalks must have some cross slope, but no more than 2.0%, in either the positive or negative direction after construction.
522-8 Curing.
Cure the concrete as specified in 520 -8. FY 2023-24 Return to Table of Contents