2513 Concrete Barrier

Section 2513. Concrete Barrier.

2513.01 DESCRIPTION.
The provisions of this section shall apply to production and construction of concrete barrier, both permanent and temporary, as shown in the contract documents. The provisions of Section 2403 shall apply.

Unless otherwise designated concrete barrier may be cast-in-place, precast in an approved casting yard or plant and hauled to the placing site, or slip formed at the project site. Precast barrier shall be produced in a plant for which equipment, procedures, and quality of concrete have been approved by the District Materials Engineer. Approved manufacturers of precast barrier are listed in Materials I.M. 571, Appendix A.

The Contractor or Fabricator shall provide technical personnel who are experienced and skilled in the procedures being used. These personnel shall collaborate fully with the Engineer in all technical aspects of the work.

Used temporary barrier rail furnished and placed as temporary barrier rail shall have been manufactured in accordance with the contract documents after December 20, 1988.

Used barrier rail must be included in installations containing units with similar shape and dimensions with compatible connecting loops.

The Contractor shall use F-shape temporary concrete barrier rail on roadways with a posted speed limit greater than 45 mph. F-shape TBR, Type A, as defined in the Standard Road Plans, shall be used in all situations requiring the railing to be in place during the winter work period as defined in Article 1108.02, Paragraph E. F-shape temporary concrete barrier rail shall be used on projects let on or after October 1, 2002.

2513.02 MATERIALS.
The materials used in concrete barrier and temporary concrete barrier rail shall meet requirements of Division 41 for the respective materials, and the following:

A. Cement.
Section 4101 shall apply. Type I or Type III Portland Cement may be used.

B. Aggregates.
Class 2 or better durability coarse aggregate shall be used unless otherwise specified.

C. Admixtures.
Section 4103 shall apply. Air entrainment shall be used. To improve workability or retard hardening, other approved admixtures may be used with the approval of the Engineer. Those containing more than 1.0% chlorides will not be allowed.

D. Bolts, Anchors, and Other Metal Fastenings.
Article 2407.02, G, shall apply.

E. Steel Reinforcing.
Section 2404 shall apply. All reinforcement for other than temporary concrete barrier shall be epoxy coated unless otherwise specified.

F. Guardrail and Barrier Markers.
Guardrail and barrier markers, if required, shall meet the requirements of Article 4186.12.

Only approved supports and bedding grout shall be used when placing permanent precast concrete barrier.

2513.03 CONCRETE.

A. Precast.
Concrete shall be as specified in Article 2513.03, B, or as approved by the Engineer, and in accordance with Section 2403. The concrete shall be proportioned, mixed, placed, and cured in a manner that will produce the minimum compressive strength at the time designated, as specified below:

Strength Before
Moving From
Casting Bed (psi (MPa))
Strength At
Age 28 Days (psi (MPa))

Precast 1750 (12) 5000 (34.5)

Strength at Age 28 Days shall be reached before storing in multilayers or shipping.

The air content of fresh, unvibrated concrete shall be 7.0%, as a target value, with a maximum variation of plus 1.5% or minus 1.0%.

B. Cast-in-Place and Slip Form.
Class C concrete in accordance with Materials I.M. 529 shall be used for cast-in-place. Class BR in accordance with Materials I.M. 529 shall be used for slip form.

Class BR mix design shall be submitted to the District Materials Engineer for approval at least 7 calendar days prior to placement. Section 2403 shall apply, except the concrete shall meet the following mix design requirements:

1. Cement for Class BR. Cement content shall be a minimum of 603 pounds per cubic yard (358 kg/m³).

2. Water. The total mixing water and free moisture in the aggregate shall not exceed the following:

Class of Concrete Pounds (kg) of Water
Per Pound (kg)
Of Cementitious Material

BR (Slip Form)
C (Cast-in-Place) 0.450
0.488

Slump for slip form rail shall be a minimum of 1/2 inch (12.5 mm).

3. Aggregates for Class BR. The combination of aggregates shall be well graded in accordance with Materials I.M. 532. The Contractor shall provide a target gradation and the following limits shall apply:

Sieves Limits

No. 4 (4.75 mm) and larger
No. 8 (2.36 mm) to No. 30 (600 ľm)
No. 50 (300 ľm)
No. 100 (150 ľm)
No. 200 (75 ľm) ą 5%
ą 4%
ą 3%
ą 2%
Maximum 1.5% Passing

A new target gradation will require approval by the Engineer.

4. Admixtures. Air entrainment shall be used. The air content of fresh, unvibrated concrete shall be 7.0%, as a target value, with a maximum variation of plus 1.5% or minus 1.0%. To improve workability and aid in air entrainment, water reducing or retarding admixtures may be used in accordance with Article 2513.02, C.

5. Fly Ash and GGBFS. The conditions and allowable rates of fly ash and GGBFS substitution shall be as follows:

Cement Type Maximum Allowable
Substitution* Time Period

Type I, II 35% GGBFS
20% Fly Ash March 16 to October 15

Type IS, IP 20% Fly Ash March 16 to October 15

Type I, II 20% Fly Ash October 16 to March 15

Type IS, IP 0% October 16 to March 15

* Maximum total mineral admixture substitution shall be 50%.

2513.04 EQUIPMENT.
Equipment shall meet requirements of Section 2001 and the following:

A. Forms.
Forms for all concrete barrier shall be true to dimensions as shown in the contract documents, true to line, mortar tight; and sufficiently rigid to maintain the required shape during placement, vibration, and curing.

Inside surfaces shall be smooth and free of any projections, indentations or offsets.

B. Bins.
Article 2001.06 shall apply.

C. Weighing and Proportioning Equipment.
Article 2001.20 shall apply. A vibrator will not be required on the cement batch hopper.

D. Mixing Equipment.
Article 2001.21 shall apply. A continuous mixer with volumetric proportioning may be used with approval of the Engineer.

2513.05 PROPORTIONING, MIXING, AND PLACING CONCRETE.
Article 2407.09 shall apply, except that finishing requirements in Article 2403.21, B, apply to temporary barrier rail only.

For precast temporary and permanent barrier, cast upside down, the bottom of the concrete, exposed at the top of the form, shall be finished as provided in Article 2403.21,.

2513.06 CURING.

A. Cast-in-Place and Precast.
The method of curing shall prevent loss of moisture and maintain an internal concrete temperature of not less than 40°F (4°C) during the curing period. Article 2407.09 ~~2407.10~~, shall apply when elevated temperature curing is used.

When nonelevated temperature curing is used, the concrete barrier shall be kept dampened with wet burlap for a minimum of 12 hours after casting. If forms remain in place during the 12 hours, only the exposed concrete surface will require the wet burlap application. Finishing operations shall be accomplished after this period and shall be completed in an expedient manner. Once finishing and any necessary repairs have been accomplished, clear curing compound shall be applied to all exposed surfaces as specified.

B. Slip Form.
Slip formed concrete barrier shall be cured by application of a clear curing compound as specified. No moist cure period will be required. Clear curing compound shall be applied to the concrete barrier rail within 15 minutes after final finishing provided that the free water (sheen) has appreciably disappeared from the concrete surface.

C. Clear Curing Compound.
A clear curing compound shall be applied, when specified, to all exposed surfaces in a fine spray to form a continuous, uniform film on the surface and vertical edges of the pavement slab as soon as the free water has appreciably disappeared, but no later than 30 minutes after finishing. The application rate shall be not less than 200 square feet per gallon (5 m²/L (0.2 L/m²)). To ensure uniform application and coverage, a fugitive dye shall be used with clear curing compounds meeting Article 4105.07. Prior to application, the curing compound shall be well agitated in the supply drum immediately before transfer to the sprayer. This compound shall also be applied promptly and at the same rate to surfaces exposed after removal of forms following finishing. If the coating is damaged within 72 hours after being applied, the affected area shall be recoated without delay. Further sealing shall not be necessary.

2513.07 REMOVAL OF FORMS.
For precast and cast-in-place concrete barrier, forms may be removed before the concrete has attained 250 psi (1.7 MPa) in flexure. If form removal interrupts the moist cure process, form removal must be accomplished without delay and the moist cure process reapplied immediately. Form removal shall not cause damage to, or deformation of, the barrier.

2513.08 FINISH.
For permanent precast and cast-in-place concrete barrier, Article 2407.14 shall apply except that the finishing operation shall not commence until completion of the initial wet cure period. Permanent precast barrier shall be free from honeycomb or surface defects. When any defects develop, production procedures shall be evaluated and corrections made. Patching of such defects shall be very limited.

Temporary barrier rail shall be finished in accordance with Article 2403.21, B.

The finish on slip form concrete barrier shall be the finish remaining after passage of the steel form and as provided in Article 2403.21, B. No further surface manipulation will be required. The finished slip form barrier shall be free from honeycomb or surface defects. Patching operations shall be done only as directed by the Engineer in accordance with Article 2407.14.

2513.09 TOLERANCES.
A newly fabricated unit of temporary barrier rail shall be free from honeycomb, surface spalling, and surface defects. Corner breaks and bottom spalls after shipping and placement shall not exceed 1 square foot (0.1 m²) of total surface area, which includes the base.

Other than honeycomb, shallow voids, not exceeding 3/4 inch (19 mm) diameter, which appear on the formed surface after proper consolidation will not be considered as surface defects and need not be filled unless they appear in an abnormal concentration.

Tolerances for concrete barrier shall be as follows:

Item Precast Fabrication ⁽¹⁾
(Permanent or Temporary) Cast-In-Place or Slip Form
Installation

Length ą 3/4 inch (ą 19 mm)

Width ą 1/4 inch (ą 6 mm) ⁽²⁾

Height ą 1/4 inch (ą 6 mm) ⁽²⁾

Horizontal Straightness (Sweep) 1/2 inch maximum in 10 feet
(12 mm maximum in 3 m) 3/4 inch maximum in 10 feet
(19 mm maximum in 3 m)

Top Straightness (Vertical) 1/4 inch maximum in 10 feet
(6 mm maximum in 3 m) 3/4 inch maximum in 10 feet
(9 mm maximum in 3 m)

Exposed Ends (Deviation from square) ą 1/4 inch (ą 6 mm)

⁽¹⁾ Installation of permanent precast barrier shall include shimming and grouting such that adjoining sections match within 1/4 inch (6 mm) on the sides and top, and the finished height is not less than required by the contract documents.
⁽²⁾ The width and depth shall not be less than required by the contract documents.

A used unit of temporary barrier rail shall not have spalls, corner breaks, and bottom spalls totaling more than 5 square feet (0.5 m²) of surface area, which includes the base.

Connecting loops on all barriers shall not be deformed and shall be true to dimensions.

Gaps between units shall not exceed the dimensions shown in the contract documents.

2513.10 HANDLING, STORAGE, AND HAULING NEW AND USED PRECAST UNITS.
Precast barrier units shall not be lifted or stressed in any way before they have developed the strength specified. Units shall be supported at designated pickup points. Connecting loops shall not be considered as pickup points. Care shall be taken during fabrication, storage, handling and transporting to prevent cracking, twisting, or other damage. Minor chips on edges may be patched with the approval of the Engineer. Breakage and chipping may be cause for rejection. Tiedowns which may cause chipping or breakage shall not be in direct contact with concrete surfaces, and units should not be subjected to excessive impact. Units damaged in such a way as to impair their appearance or suitability, in the opinion of the Engineer, shall be replaced by the Contractor at no additional cost. New barrier units shall be marked in accordance with Materials I.M. 571 for the proper identification.

Temporary barrier rail units that are rejected will be marked with an orange painted "R" approximately 12 inches (300 mm) high and 6 inches (150 mm) wide on both ends to show that piece has been rejected for use as a traffic control device by the Engineer.

2513.11 METHOD OF MEASUREMENT.
The length in linear feet (meters) of permanent concrete barrier will be based on the contract quantity from end to end of the barrier, including end sections, as shown in the contract documents.

Reinforcement in concrete barrier for bridge structures will be measured as provided in Article 2404.09. Reinforcement in concrete barrier for other than bridge structures will not be measured separately.

2513.12 BASIS OF PAYMENT.
For the number of linear feet (meters) of Concrete Barrier, of the type specified, satisfactorily completed, the Contractor will be paid the contract unit price.

Reinforcement in concrete barrier for new bridge structures will be paid for as provided in Article 2404.10. The quantities will be included in the quantities for the superstructure or abutments. Reinforcement in retrofit concrete barrier will not be paid for separately.

The payment as described above shall be considered full compensation for all work involved.

Class of Concrete	Pounds (kg) of Water Per Pound (kg) Of Cementitious Material
BR (Slip Form) C (Cast-in-Place)	0.450 0.488

	Strength Before Moving From Casting Bed (psi (MPa))	Strength At Age 28 Days (psi (MPa))
Precast	1750 (12)	5000 (34.5)

Sieves	Limits
No. 4 (4.75 mm) and larger No. 8 (2.36 mm) to No. 30 (600 ľm) No. 50 (300 ľm) No. 100 (150 ľm) No. 200 (75 ľm)	ą 5% ą 4% ą 3% ą 2% Maximum 1.5% Passing

Cement Type	Maximum Allowable Substitution*	Time Period
Type I, II	35% GGBFS 20% Fly Ash	March 16 to October 15
Type IS, IP	20% Fly Ash	March 16 to October 15
Type I, II	20% Fly Ash	October 16 to March 15
Type IS, IP	0%	October 16 to March 15
* Maximum total mineral admixture substitution shall be 50%.

Item	Precast Fabrication ⁽¹⁾ (Permanent or Temporary)	Cast-In-Place or Slip Form Installation
Length	ą 3/4 inch (ą 19 mm)
Width	ą 1/4 inch (ą 6 mm)	⁽²⁾
Height	ą 1/4 inch (ą 6 mm)	⁽²⁾
Horizontal Straightness (Sweep)	1/2 inch maximum in 10 feet (12 mm maximum in 3 m)	3/4 inch maximum in 10 feet (19 mm maximum in 3 m)
Top Straightness (Vertical)	1/4 inch maximum in 10 feet (6 mm maximum in 3 m)	3/4 inch maximum in 10 feet (9 mm maximum in 3 m)
Exposed Ends (Deviation from square)	ą 1/4 inch (ą 6 mm)
⁽¹⁾ Installation of permanent precast barrier shall include shimming and grouting such that adjoining sections match within 1/4 inch (6 mm) on the sides and top, and the finished height is not less than required by the contract documents. ⁽²⁾ The width and depth shall not be less than required by the contract documents.