00820.00 858 Section 00820 - Concrete Barrier
Description
00820.00Scope - This Work consists of constructing precast and fixed form cast -in-place portland
cement concrete barrier, to the lines and grades shown or established. This Work also consists of removing existing concrete barrier and reinstalling the barrier in its original location, as shown.
Materials
00820.10Materials - Furnish Materials meeting the following requirements:
Commercial Grade Concrete ...............00440, except as provided in this Section Deformed Bar Reinforcement ................................................................ 02510.10 Granular Wall Backfill ............................................................................ 02630.11 Portland Cement Grout ......................................................................... 02080.40 Preformed Joint Filler ............................................................................ 02440.10 Welded Wire Reinforcement ................................................................. 02510.40
00820.11Other Materials:
shall be modified as follows:
and 02690.30( d). Test results shall be no more than 1 year old.
and 02690.20( c). Test results shall be no more than 1 year old.
galvanized according to AASHTO M 232 ( ASTM A153).
according to AASHTO M 232 ( ASTM A153) and ASTM A143.
channel, hot -dip galvanized after fabrication according to AASHTO M 232 ( ASTM A153) and ASTM A143.
each precast concrete barrier piece an identifying code consisting of the initials of the barrier manufacturer, the date of casting and the form number. Barrier pieces without identifying code will not be accepted.
00820.12Re -use of Concrete Barriers - Used precast concrete barriers may be placed in
permanent installations according to the following:
temporary applications on the Project may be reused in permanent installations, provided they:
• Are in good condition, without visible cracks, chips or spalls. • Present a surface of uniform texture and appearance. 00820.43 859 • Are free of markings, except as required by 00820.11(e). • Are given two coats of a water -based coating Material meeting the requirements of 02210.30 after installation in final position.
be reused in permanent installations, provided they meet all the requirements of this Section and, prior to delivery to the Project Site:
• The Contractor furnishes documentation required by 00165.10(b). • Barriers are restored to like-new condition, without visible cracks, chips, spalls or corroded loops. • Barriers present a surface of uniform texture and appearance. • Barriers are free of markings, except as required by 00820.11(e).
Apply two coats of a water -based coating Material meeting the requirements of 02210.30 after installation in final position.
after installation, immediately repair it to the Engineer's satisfaction or replace it with an undamaged section, at no additional cost to the Agency.
00820.15Quality Control - Provide quality control according to Section 00165
Labor
00820.30Quality Control Personnel - Provide a technician having a QCT technical certification
Construction
00820.40General - Construct cast -in-place barrier using fi xed forms unless specifically directed
otherwise. Use the same barrier design in any continuous run of barrier.
00820.41Line and Grade - Place precast barrier sections on the Pavement surface. New Pavement
surfaces placed as a part of this Project shall meet the appropriate smoothness requirement prior to placing the barrier. If corrective work is required for existing surfaces to receive concrete barrier, it will be paid according to 00195.20.
Place the barrier sections so that the joints offset no more than 1/4 inch transversely and no more than 1/2 inch vertically. Construct the top and face of finished barriers true and straight. The top surface of the barriers shall be uniform width and free fro m humps, sags, or other irregularities. When a 12-foot straightedge is laid on the top or face of the barrier, the surface shall not vary more than 1/4 inch from the edge of the straightedge, except at grade breaks or curves. To compensate for variations in the R oadway grade and cross Slope , adjust the height of the barrier at no additional cost to the Agency.
00820.42Concrete Construction - Construct concrete barrier according to Section 00440 except
as provided in this Section.
00820.43Curing - Cure barriers as follows:
methods:
00820.44 860 (1) Water Cure - Cover with burlap, canvas or other satisfactory Material and keep moist for at least 7 Calendar Days.
procedures:
• Allow free moisture to flash off, but only until the concrete surface does not glisten, and never for more than 1 hour. • Apply latex paint from the QPL as follows: • Apply first coat at an application rate of 150 square feet per gallon. • Allow first coat to air dry for 1 hour. • Apply second coat at the same rate as above, with application direction transverse to the direction that the first coat was appl ied.
Barriers cured in this manner will be considered to have met the surface finishing requirements of 00820.45 except that additional coats may be necessary to provide uniform coverage and appearance to correct construction damage.
satisfactory Material and keep moist for at least 7 Calendar Days.
enclosure constructed to contain live steam and to minimize moisture and heat loss. The steam shall be at 100 percent relative humidity to prevent loss of moisture and to pro vide excess moisture for proper hydration of cement. Do not apply the steam directly to the concrete. Equip the steam supply line to the enclosure with a motor -operated, modulating steam control valve operated by a temperature-sensing element that measures the temperature within the enclosure. Distribute the steam within the enclosure through suitable ports located on each side of the enclosure at not more than 30 foot centers, or closer if necessary, to keep the units being cured completely and uniforml y surrounded with live steam.
Equip the enclosure with a 24 -hour recording thermometer, and record the temperature on a single chart for each 24- hour period.
Apply the steam after the initial set of the concrete as determined by ASTM C403. Continue steam curing until the barrier concrete reaches a minimum compressive strength of 2,000 psi as determined by Contractor test cylinders or as approved.
00820.44Joints for Cast -in-Place Concrete Barriers :
If the placement of the barrier is stopped at a normal contraction joint location, construct an expansion joint at that location, before proceeding with the placement of the barrier, as shown.
shown.
position on one side of the joint before placing concrete on the other side.
00820.49 861 00820.45 Surface Finishing - After stripping forms and while the concrete is still green, remove all fins and form marks, and repair all rock pockets and holes having a surface opening over 3/8 inch in diameter with portland cement grout conforming to 02080.40. Prevent grout from drying prematurely. Additional finishing after precast concrete barrier is set in its permanent position may be required to present a surface of uniform texture and appearance.
Coat the top and sides of all permanent barriers with a minimum of two coats of a latex paint from the QPL. Use additional coats as necessary to provide uniform coverage and appearance. Clean and t horoughly saturate with water the surfaces to be coated. Coat while damp. The second coat may be applied when the previous coat does not adhere to the fingers when touched lightly.
00820.46Remove and Reinstall Existing Barrier - Remove, protect, and reinstall existing barrier
as shown. Documentation is not required for existing barrier that is removed and reinstalled within the Project Site.
Repair any damage according to 00820.12(c). Apply two coats of a water -based coating Material meeting the requirements of 02210.30 after installation in the final position.
00820.47Replacement or Price Reduction - Remove and replace barrier represented by cylinders
that fail to meet the minimum strength requirement, at no additional cost to the Agency. If the Engineer determines the low -strength barrier is suitable for the purpose intended, the barrier may be accepted according to 00150.25.
00820.48Inspection - Fabrication of barrier outside of the State of Oregon creates additional
inspection costs to the Agency. The Contractor's payment for barrier will be reduced according to 00165.91.
00820.49Slipform Construction for Single Slope Barrier - Single-slope, 42 inch high, concrete
barrier may be slipformed if the Plans contain details for slipforming.
Prior to slipforming permanent single-slope concrete barrier, comply with one or both of the following requirements as directed:
Be placed off the final barrier location site Have the same section and reinforcement as detailed Include one typical contraction or expansion joint. Be removed and disposed of at no additional cost to the Agency
slipformed single- slope concrete barrier. For each project, provide the name and phone number of a person the Engineer may contact to determine the success of the installation. The Engineer will determine whether to allow slipforming on the current project. If slipforming single- slope concrete barrier is permitted, comply with the following:
Meet the requirements for cast -in-place construction. Use Class 3300 - 1 1/2 or Class 3300 - 3/4 portland cement concrete meeting the requireme nts of Section 02001. Provide concrete with a slump of 1 inch ± 1/2 inch. Brush -finish single- slope concrete barrier surfaces with vertical strokes and then paint according to 00820.45. 00820.80 862 Keep the top and faces of the finished single- slope barrier free from sags, humps and other irregularities. Maintain contraction joints and expansion joints to the dimensions shown until the concrete sets. Use slipforming only for section of single-slope barrier with constant dimensions. Use fixed forms where dimensions var y, as at luminaire or signal supports and at barrier end transitions. Remove and replace any unsatisfactory W ork at no additional cost to the Agency.
Measurement
00820.80Measurement - The quantities of concrete b arrier will be measured on the length basis,
according to the following:
• Cast -In-Place Barriers - Cast-in-place barrier will be measured along the line and grade of each separate run, including terminal sections and transition sections.
• Precast Barriers - Precast barrier will be the laying length of a standard section, as shown on the applicable Standard Drawings , multiplied by the number of standard sections installed in each separate run. Non- standard sections, terminal sections and transition sections will be measured separately and added to the total length of standard sections. Remove and Reinstall Existing Concrete Barrier - Removing and reinstalling existing concrete barrier will be measured along the line and grade of each separate run, including terminal section and transition secti ons, by actual length of barrier in place.
The quantities of concrete barrier around Median obstacles will be measured on the unit basis.
Measurement for the removal of concrete barrier that will not be removed and reinstalled according to this Section will be measured and paid for according to Section 00310.
Payment
00820.90Payment - The accepted quantities of Work performed under this Section will be paid for
at the Contract unit price, per unit of measurement, for the following items:
Pay Item Unit of Measurement
Item (c) includes cast -in-place transitions, narrow base Shoulder barrier secured to the R oadway, granular wall backfill, 4-inch PCC slab with welded wire reinforcement, and required expansion joint filler.
Item (d) includes securi ng concrete barrier to the R oadway or bridge deck surface with barrier pins, anchor rods, or similar devices.
Payment will be payment in full for furnishing and placing all Materials, and for furnishing all Equipment , labor, and Incidentals necessary to c omplete the Work as specified.
00820.90 863 No separate or additional payment will be made for :
excavating and backfilling buried ends of concrete barrier securing concrete barrier to the R oadway by means of grout or keyways moving, stockpiling, handling, and pinning removed and reinstalled concrete barrier.
Payment for removal of concrete barrier that will not be removed and reinstalled according to this Section will be measured and paid for according to Section 00310.