440Plain Portland Cement Concrete Shoulders

440.1General Description

The work includes constructing plain Portland cement concrete shoulders on a prepared subgrade or subbase according to these Specifications. Construct the shoulders to conform with lines, grades, thicknesses, and cross sections shown on the plans or established by the Engineer. 440.1.01 Definitions General Provisions 101 through 150. 440.1.02 Related References

AASHTO T 22 AASHTO T 23 ASTM C 94, Requirements for Uniformity AASHTO T 97 AASHTO T 126 GDT 26 GDT 27 GDT 28 GDT 32 440.1.03 Submittals

Submit to the Engineer a concrete mix design prepared by a qualified testing laboratory. The Engineer will transmit the design to the Office of Materials and Research for approval. Ensure that the concrete mix design conforms to Subsection 440.2.A, Composition of Class SP Concrete. 554 554 554 554 554 554 554

440.2Materials

Use materials that conform to Subsection 430.2, Materials, for Portland cement concrete pavement, or Subsection 815.2.01 for graded aggregate. Gradation requirements are modified to require 30 to 45 percent by weight to pass the No. 10 (2 mm) sieve for graded aggregate.

Ensure that the concrete mix design conforms to the following requirements:

1) G raded Aggregate meeting the requirements in Subsection 815.2.01 and as modified in Subsection 440. 2, Materials may be used if the shoulders are not constructed in continuity with travel lanes. 2) G raded aggregate may be used as the coarse and fine aggregate portions of the concrete mix except that the gradation is modified to require 30 to 45 percent passing the No. 10 (2 mm) sieve. 3) U se aggregates manufactured to meet the gradation at the quarry or blended at the plant site to produce the desired results. Ensure a uniform aggregate gradation when charging the mixer.

Use concrete aggregate in shoulders constructed in continuity with travel lanes as specified in Subsection 430. 2.C, Composition of Concrete and Subsection 430.2.C.2, Fine Aggregate.

ix Design Criteria Base the proportions of Class SP concrete mix designs on the following requirements: Minimum Cement Content per Cubic Yard (meter) Concrete CWT (kg) Maximum Water- Cement Ratio Lbs./lb. (kg/kg) Design Air Content Range (%) Class SP Concrete 4.25 (250) 0.75 (0.75) 5.0 to 7.0

Use fly ash as an additive in concrete to promote workability and plasticity or as a partial repl acement fo r Portland cement if the following limits are met:

of cement.

Calculate the water-cement ratio based on the total cement material in the mix including fly ash. Construct Portland cement concrete shoulders with the same class of concrete required in the adjacent sections when constructed in continuity with travel lanes, ramps, acceleration lanes, deceleration lanes, or other sections. Produce evidence that the proportions have the potential for strength development at 28 days as required in Subsection 440.3.06.B, Approval of Mix Design Proportions. 440.2.01 Delivery, Storage, and Handling General Provisions 101 through 150. 555 555 555 555 555 555 555

440.3Construction Requirements

440.3.01 Personnel General Provisions 101 through 150. 440.3.02 Equipment Use equipment that meets the requirements in Subsection 430.3.02, Equipment. 440.3.03 Preparation Prepare the roadbed as required by the Plans and Specifications before placing the concrete shoulder. Ensure that the foundation immediately under the concrete shoulder and the areas supporting the paving equipment will not contribute to deficient shoulder thicknesses or excessive yield losses. 440.3.04 Fabrication General Provisions 101 through 150. 440.3.05 Construction

Place concrete as follows:

nless truck mixers, truck agitators, or non-agitating hauling equipment are equipped to discharge concrete wi thout segregation, concrete shall be unloaded into an approved spreading device and mechanically spread on grade.

NOTE: Do not allow personnel to walk in freshly mixed concrete with shoes coated with harmful substances.

a nd both sides of joint assemblies.

o not continue vibration if puddling or excessive grout accumulates on the surface. NOTE: Do not use grout that accumulates ahead of the paver in construction or expansion joints.

co ncrete is centered on the joint assembly.

Place the reinforcement according to details on the Plans. Do not allow reinforcement placement to disrupt or damage the concrete. Do not insert lane tie bars into unsupported sides of fresh concrete.

Vibrate the full width and depth of the shoulder. Do not allow the vibrators to contact the foundation, load transfer d evices, side forms, or joints. I f the vibrator does not produce uniform consolidation and density, stop the operation to furnish methods or eq uipment that will produce pavement according to the Specifications. 556 556 556 556 556 556 556

Finish the concrete pavement as follows:

porous areas.

grooving plastic concrete, brooming, or burlap drag.

Immediately after finishing, remove the loose material and clean the grout from the surface of adjacent lanes.

Use the joint, type of filler, and type of sealer designated in the plans. C onstruct joints according to Subsection 430.3.05.J, Provide Joints, Section 461, and the following:

Saw transverse contraction joints in the shoulder to abut like joints in the roadway, or construct joints as shown on the plans.

ngitudinal Joints

the plans.

co ncrete, or by using mechanical equipment to insert them while placing concrete.

Form transverse construction joints when concreting operations will be interrupted for more than 1 hour. Construct the joint according to Subsection 430.3.05.K.5, Construction Joints, except string line requirements are 1/4 in. (6 mm) maximum deviations in 15 ft. (4.5 m).

Cure concrete according to Subsection 430.3.05.L, Cure the Concrete.

Before using a shoulder as a haul road for loaded or unloaded vehicles:

least 7 days old.

tr affic encroachment.

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440.3.06 Quality Acceptance

Produce Portland cement concrete shoulders using Class SP concrete as follows:

metho ds in this specification.

the drum.

of ASTM C 94, Requirements for Uniformity, but never reduce the mix time to less than 50 seconds.

The Office of Materials and Research will review concrete mix designs and will verify that compressive strength d evelopment is according to AASHTO T 126 and T 22. The Department will approve material combinations and mix designs using approved materials and complying with Subsection 440.2.A, Composition of Class SP Concrete, and the following:

Take at least 5 normally cured flexural specimens to ensure that the 28-day laboratory flexural design strength i s according to AASHTO T 126 and T 97 and is within the following design acceptance range (DAR). Class SP Concrete DAR = 400 psi ± .67s (2.8 MPa ± .67s) wheres = The standard deviation of 28-day flexural specimens for a combination of materials and mix proportions prepared together. Do not use a value of s greater than 37 psi (255 kPa) to calculate DAR. A mixture may be used that exceeds the upper limit of the DAR.

ompressive Strength Prepare and test 6 cylinders according to AASHTO T 126 and T 22 to determine the 28-day laboratory compressive strength for Class SP concrete. Ensure that it exceeds the following minimum laboratory performance value (LPV). Class SP Concrete LPV = 2,000 psi + .18R (13.8 MPa + .18R) where R = The difference between the largest observed value and the smallest observed value for 28-day compressive strength specimens for a combination of materials and mix proportions prepared together.

Determine the aggregate surface moisture and apply free moisture corrections to the approved mix design. The E ngineer will verify that these corrections are made properly. Adjustments to the approved proportions of the fine aggregate, coarse aggregate, and water may be made acco rding to these guidelines: • Do not decrease the cement factor. • Do not increase the water-cement ratio. • Ensure that adjustments produce concrete proportions according to this specification. • Notify the Engineer before making adjustments. 558 558 558 558 558 558 558

Ensure that variations in consistency and concrete air content are within the following limits:

Immediately before placing, determine concrete slump using GDT 27. Concrete for Portland cement concretes houlders will not be accepted if the slump value is greater than 3 in (75 mm).

Determine the concrete air content immediately before placement using GDT 26 or GDT 32. Concrete will not be accepted with an air content outside the following limits: Lower acceptance limit 3.0 percent Upper acceptance limit 7.5 percent

Portland cement concrete shoulder strength shall be accepted based upon its 28-day compressive

strength development.

continuously, except for overnight or other minimal discontinuance.

average strength of the two cylinders tested according to AASHTO T 22.

Determinations at 28 Days table.

acceptance limit shown in the 1.00 pay factor, the Contractor may leave the lot in place at a reduced Unit

Price according to the Pay Factor Schedule for Strength Determinations at 28 Days.

the Engineer may order the removal of any or all of the concrete in the lot.

Pay Factor Schedule for Strength Determinations at 28 Days

Acceptance Limits for Pay Factor Levels

1.00LAL* 0.95 LAL 0.70 LAL

Class SP Concrete 2000 psi (13.8 MPa) + 0.18 R 2000 psi (13.8 MPa) - 0.07 R 2000 psi (13.8 MPa) - 0.30 R

* Lower Acceptance Limit (LAL)

The pay factor is 0.50 for concrete that remains in place when outside the 0.70 pay factor limits for

compressive strength. 559559559559559559559

Determine the thickness by measuring the fresh concrete depth at the shoulder edges at least every 500 ft.

(150 m) of shoulder length.

The Engineer will evaluate areas deficient by more than 1 in. (25 mm) thick. If the Engineer requires removal,

remove and replace the shoulder pavement in full cross sections according to plan requirements.

If removal and replacement are not required, payment is made at 50 percent of the Contract Unit Price for areas

deficient by more than 1 in. (25 mm). Areas that are deficient by more than 0.5 in. (13 mm) through 1 in. (25 mm)

will be paid for at 70 percent of the Contract Price per square yard (meter).

440.3.07 Contractor Warranty and Maintenance

General Provisions 101 through 150.

440.4Measurement

The work to be paid for under this Item is the number of square yards (meters) of Portland cement concrete shoulders

completed and accepted as measured in place. The measurement width is the shoulder width shown on the plan

typical cross-section. The measurement length is along the surface at the inside edge of the paved shoulder.

440.4.01 Limits

General Provisions 101 through 150.

440.5Payment

The work will be paid for at the Contract Unit Price per square yard (meter). Payment is full compensation for providing

materials, reinforcement, equipment, and labor, mixing, hauling, handling, placing, and providing incidentals to

complete the work.

Payment will be made under:

Item No. 440 Plain Portland cement concrete shoulders, type___ Per square yard (meter)

440.5.01 Adjustments

The Contract Unit Price per square yard (meter) of concrete shoulder will be adjusted for concrete shoulder accepted

with a 28-day compressive strength or thickness deficiency.

If a shoulder section is deficient in thickness and compressive strength, the Contract Unit Price will be adjusted by the

total reduction of the application of the two individual percentages shown in the Pay Factor Schedule and Subsection

440.3.06.F, Thickness Tolerances.

For combined deficiencies of 50 percent or more, the Engineer may allow the shoulder to stay in place or require its

removal. If the Engineer requires shoulder pavement removal, the original pavement nor its removal will be paid for.

Pavement replaced satisfactorily will be paid for at the appropriate Unit Price.. 560 560 560 560 560 560 560