623CONCRETE MEDIAN BARRIER

623.1DESCRIPTION—This work is construction of cement concrete median barrier.

623.2MATERIAL—

• Class AA Cement Concrete. Section 704, except use Class AAA Cement Concrete for precast barrier

• Class AA Cement Concrete (Slip-Forming). Section 501

• Premolded Expansion Joint Filler. Section 705.1

• Reinforcement, Epoxy Coated or Galvanized. Section 709.1, 709.3, or 709.4

• Barrier Loops. ASTM A36, hot rolled round bar; galvanize after bending as specified in Section 1105.02(s)

• Pins. ASTM A449, Type 1 , unthreaded rod (straight) - 1 inch diameter; galvanized as specified in Section 1105.02(s) after 3/8-inch hole is drilled through pin and washer is welded to pin.

• Washers. ASTM A572, Grade 50; galvanized as specified in Section 1105.02(s) after washer is welded to pin.

• Curing and Protecting Covers. Sections 711.1 and 711.2(a)

• Joint Sealing Material (Longitudinal Joints). Section 705.4(b) or (c)

• Joint Sealing Material (Transverse Joints). Section 705.4(b) or (c), between concrete median barrier sections with pin-and-loop connections

• Mortar. Section 1001.2(d)

• Coarse Aggregate, Type A, No. 8, No. 57, or No. 67. Section 703.2

• Subbase Material. Section 350.2

• Precast Concrete Barrier. Section 714

• Structural Steel (Plates for Joints). Section 1105.02(a)2. Galvanized as specified in Section 1105.02(s)

• Penetrating Sealers for Reinforced Concrete Surfaces. Section 1019

• Intermediate Curing Compound. Section 711.2(c)

• Caulking Compound (Vertical Joints). Section 705.7(b)

• Superpave Asphalt Mixture Design, Asphalt Wearing Course or Asphalt Binder Course. Section 413.2

• Rapid Set Concrete Patching Material. Section 525.2(c)

• Geotextile, Class 4, Type A. Section 735 - Table A

623.3CONSTRUCTION —As shown on the Standard Drawings , as specified in the applicable parts of

Section 1001.3, and as follows:

acceptance before starting work. Fill surface blemishes larger than 1/2 inch with mortar, as directed. Install barrier mount delineation devices as specified in Section 937.3(a) and (b). For sections of barrier indicated as removable sections, install a bond breaker, such as asphalt impregnated paper or polyethylene, to facilitate removal. Provide lifting methods for handling, installing, and removing the barrier units. If not in use, plug lifting devices with removable plastic or other acceptable plugs. Join new concrete median barrier and existing barrier, as indicated, and as directed. Construct cast-in-place barrier and slip-form barrier according to the weather restrictions as specified in Section 501.3(b). Cure cast-in-place barrier and slip -form barrier as specified in Section 1001.3(p)3.a or Section 516.3(j) except white membrane curing compound may be used to cure barrier subject to the application of protective coatings and the first paragraph specified in Section 501.3(l)1.c does not apply. Apply a protective coating to barriers a minimum of 28 days after concrete placement as specified in Section 503.3(b). Before application, thoroughly dry and clean concrete surfaces of dirt, debris, oil, grease, and foreign matter that would prevent protective coating penetration, adhesion, or drying. Do not apply protective coating to precast barrier units as specified in Section 714.

apply an intermediate monomolecular film curing agent as specified in Section 501.3(l) immediately after the extruded concrete surface leaves the slip form machine or immediately after necessary offsets and fins are removed by light troweling. Do not touch the barrier extruded concrete surface as it leaves the slip -form machine, except to immediately remove offsets and fins by light troweling. Adjust the operation to correct any condition causing surface blemishes larger than 1/2 inch. If the adjustments do not correct the condition within 30 linear feet, halt the operation until the condition is corrected, either by adjustments to the operation or by adjustments to the concrete mix. Do not use an intermediate curing compound or water on the completed barrier to correct imperfections.

20 foot intervals. Saw as soon as possible after the concrete sets sufficiently to preclude raveling during the sawing but before any shrinkage cracking occurs in the concrete. The depth of saw cut may be decreased at the edge adjacent to the pavement to obtain a maximum depth without pavement damage. Tool the joint edges adjacent to the premolded expansion joint material. Place 3/4-inch premolded expansion-joint material, cut to conform to the cross-sectional area, at structures, at the end of the workday, and at the ends of cast-in-place barrier as shown on the Standard Drawings. Construct longitudinal joints a maximum of 1/4 inch wide on both sides of the barrier, as indicated. Seal the longitudinal joint as specified in Section 501.3(n). Seal all vertical contraction and construction joints with an approved caulking compound. Trim 3/4 -inch premolded expansion -joint material at construction joints to create a notch for caulking c ompound. Do not seal the vertical face joints between precast barrier sections . Apply joint sealing material in the transverse joints between precast concrete median barrier sections at the locations as shown on the Standard Drawings. Place tangent precast barrier sections so transverse joints have a minimum width of 1 inch and a maximum width of 2 inches. Do not damage barrier edges during placement.

rub to correct irregularities until the full curing period has elapsed. Correct all irregular surfaces by rubbing with a silicon carbide stone. Do not brush finish or plaster. After removing the forms, fill minor defects with mortar. Promptly remove and replace rejected barrier.

within 1/4 inch in all directions and across the joints. Test the top and side surfaces using a 10 -foot

straightedge. Hold the straightedge in successive positions for the entire length of the barrier and advance in stages of not more than 5 feet. Remove and replace barrier with deviations in excess of 1/4 inch as measured from the testing edge of the straightedge.

barrier and single face concrete barrier transitions. Place materials behind single face concrete barrier and single face concrete barrier transitions (with fill and without fill) as shown on the Standard Drawings.

Connections. Sawcut a 6-inch-wide strip of pavement beside the longitudinal joint of the precast concrete median barrier. Remove the adjacent pavement with a jackhammer to a depth below the bottom of the precast concrete median barrier. Dispose of removed pavement as specified in Section 104.06. Remove the damaged precast concrete median barrier sections and install new sections. Patch asphalt pavement with an asphalt wearing course or binder course, as indicated. Compact the asphalt wearing course or binder course with a hand operated impact rammer. Patch concrete pavement with a rapid set concrete patching material as specified in Section 525.2(c). Seal the longitudinal joint as specified in Section 501.3(n). Apply joint sealing material in the transverse joints between precast concrete median barrier sections at the locations as shown on the Standard Drawings.

indicated, as shown on the Standard Drawings, and as specified in Section 1001.3.

623.4MEASUREMENT AND PAYMENT—

For the type indicated.

For the type indicated.

For the type indicated.

For the type indicated.

For precast units, this work is incidental to that item. For cast-in-place units, this work will be paid for the type indicated as specified in Section 1019.4.

Includes excavation, subbase, moment slab, barrier, reinforcement, and any other miscellaneous items required for the construction of the moment with barrier and transition.