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60-4.04 CORING CONCRETE

60-4.04A General

60-4.04A(1) Summary


Section 60-4.04 includes specifications for coring holes through concrete structures.

60-4.04A(2) Definitions


Reserved

60-4.04A(3) Submittals


If cored holes are greater than 10 feet in length, submit:

1. Work plan for the coring activities, including methods and equipment to be used

2. Labeled cores
If reinforcement shown not to be cut is cut during coring operations, submit a work plan for (1) repairing the cut reinforcement and (2) preventing cutting of additional reinforcement. Allow 3 business days for review.

60-4.04A(4) Quality Assurance


Reserved

60-4.04B Materials


Water for coring activities must either (1) be from the local water supply or (2) contain:

1. Not more than 1,000 ppm chlorides as Cl

2. Not more than 1,300 ppm of sulfates as SO4

3. No impurities that discolor the concrete or etch the surface



60-4.04C Construction


Use coring methods that do not shatter or damage the concrete adjacent to the holes.

Stop coring operations if reinforcement shown not to be cut is cut during coring operations. Do not resume coring operations until your work plan is authorized.

If cored holes are greater than 10 feet in length:

1. Alignment of the cored hole must not deviate from that shown by more than 1/2 inch per 10 feet of length with a total maximum deviation of 3 inches.

2. Label each core with the core location immediately after coring.
Do not allow water from coring activities to fall onto traffic, flow across shoulders or lanes occupied by traffic, or flow into gutters or other drainage facilities.

60-4.04D Payment


The payment quantity for core concrete is the length measured along the centerline of the hole. The payment quantity includes the length of any expansion joints.

60-4.05 CORING AND PRESSURE GROUTING DOWELS

60-4.05A General


Section 60-4.05 includes specifications for coring holes through concrete and grouting dowels into the cored holes.

Coring must comply with section 60-4.04.


60-4.05B Materials


Grout must comply with ASTM C1107 or ASTM C845, Type K, with a compressive strength of 5,000 psi at 28 days when tested under California Test 551.

Dowels must comply with the specifications for bar reinforcing steel in section 52.

Water for grout must comply with the specifications for water in section 90-1.02D.

Admixtures must not contain more than 500 ppm of chlorides as Cl when tested under California Test 422 and not more than 2,500 ppm of sulfates as SO4 when tested under California Test 417.


60-4.05C Construction


Clean loose and foreign material from concrete and steel surfaces that will be in contact with the grout. Flush holes with water and let them dry to a surface-dry condition immediately before grouting.

Seal the ends of holes after placing the dowels. Place a vent tube at one end of the hole and an injection feed tube at the other end of the hole. For holes with only a single end, place vent and injection feed tubes in the same end. Place tubes such that the air will vent and the hole will be completely filled with grout.

Mix grout under the manufacturer's instructions.

Pump grout into holes. Use sufficient pressure so that the hole is free of voids. Continually waste grout until air and water eject from the vent tubes and there are no visible slugs.


60-4.05D Payment


Payment for furnishing dowels is not included in the payment for core and pressure grout dowel.

60-4.06 STEEL COLUMN CASINGS

60-4.06A General

60-4.06A(1) Summary


Section 60-4.06 includes specifications for fabricating, installing, and cleaning and painting steel column casings.

Column casings must comply with the specifications for structural steel in section 55.

Cleaning and painting column casings must comply with the specifications for cleaning and painting new structural steel in section 59-2.

60-4.06A(2) Definitions


Reserved

60-4.06A(3) Submittals


Reserved

60-4.06A(4) Quality Assurance


For field welding of column casings:

1. Only visual inspection is required

2. 2nd sentence of clause 3.13.2 and the 1st sentence of clause 3.13.3 of AWS D1.5 do not apply.

60-4.06B Materials

60-4.06B(1) General


Steel for casings must comply with ASTM A36/A36M or ASTM A709/A709M, Grade 36.

Mortar must comply with section 51-1.02F.

Polyethylene must have a compressive strength of at least 10 psi at no more than 15 percent deflection when tested under ASTM D3575, Suffix B.

Drain extension pipe must comply with the specifications for drainage piping in section 75-3.


60-4.06B(2) Grout


Grout must consist of cement and water, and may contain an admixture if authorized. Do not exceed 5 gallons of water per 94 lb of cement.

Cement must comply with section 90-1.02B(2).

Water must comply with section 90-1.02D.

Admixtures must comply with section 90, except admixtures must not contain chloride ions in excess of 0.25 percent by weight.

For noncircular columns with a maximum gap greater than 4 inches, extend the grout as follows:

1. Aggregate must consist of at least 70 percent fine aggregate and approximately 30 percent pea gravel, by weight.

2. Fine aggregate must comply with section 90-1.02C(3).

3. Size of pea gravel must be such that 100 percent passes the 1/2-inch sieve, at least 90 percent passes the 3/8-inch sieve, and not more than 5 percent passes the no. 8 sieve.

4. Minimum cement content of the grout must not be less than 845 lb/cu yd.
Mix the grout as follows:

1. Add water to the mixer followed by cement and any aggregates or admixtures.

2. Mix the grout with mechanical mixing equipment that produces a uniform and thoroughly mixed grout.

3. Agitate the grout continuously until the grout is pumped.

4. Do not add water after initial mixing.

60-4.06C Construction

60-4.06C(1) General


Remove and dispose of all material from the space to be occupied by column casing materials.

Bond polyethylene to column surfaces where shown. Use an authorized waterproof adhesive. Apply adhesive to the entire contact surface.

Use spacers to center casings around columns during placement. You may weld spacers to the inside of casings. Do not use spacers in areas where polyethylene is used.

Paint the information that is on existing columns onto casings under section 51-1.03E(1).


60-4.06C(2) Painting


Apply the undercoat before shipment to the job site. Do not paint surfaces that are to be thermal spray coated or covered with polyethylene.

Apply final coats after installing the casing.


60-4.06C(3) Grouting


Grout the space between casing and column faces.

Grouting equipment must comply with section 50-1.03B(2)(d)(ii).

If hot weather conditions will contribute to quick stiffening of the grout, cool the grout by authorized methods as necessary to prevent blockages during pumping activities.

If freezing weather conditions are anticipated during and following the placement of grout, provide adequate means to protect the grout in the casings from damage by freezing.

Do not:

1. Allow the grout temperature to rise above 90 degrees F during mixing and pumping



2. Grout when the ambient or grout temperature is less than 50 degrees F
Limit the height of each grout lift to minimize casing undulations and displacements. Undulations in the casing surface must not exceed 1/4 inch in 12 inches. Total casing displacement from the position shown must not exceed 2 inches at any point.

You may use bracing or other means to restrain casing. Except where shown, restraints may not pass through columns.

Allow grout to harden before placing the next lift of grout unless a bracing system is used.

The maximum height of grout lifts for portions of casings with polyethylene is 10 feet.

Install external injection valves for grouting casings. Begin filling casing from the bottom. Space valves so that grout fills the void between the casing and the column.

Seal casings at the bottom. Pump grout such that a uniform grout head around the column is maintained and no visible water or air is ejected from the top of the grout. Cover grout at the casing top with mortar. Slope mortar to drain.

Remove accessories from casings no sooner than 24 hours after placing grout. Voids must be filled with mortar and finished flush with the exterior casing surface.

60-4.06D Payment


Not Used



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