Page images
PDF
EPUB

more than one-half the width of a roll, shall then be mopped with hot asphalt or tar and a full-width strip of fabric shall be pressed into place as before, so as to cover completely the first strip. This second strip and an adjoining area of the concrete surface shall then be mopped with hot asphalt or tar and the third strip of fabric placed so as to lap the first strip by not less than 4 inches. This process shall be continued until the entire surface is covered, each strip of fabric lapping at least 4 inches over the last strip but one. The entire surface shall then be mopped with hot asphalt or tar. The work shall be so regulated that at the close of the day's work the required mopping shall have been applied to all the fabric in place. Special care shall be taken to insure that all laps are thoroughly sealed down.

Under no circumstances shall one layer of fabric touch another layer at any point or touch the unmopped surface. In all cases the mopping on concrete shall cover the surface so that no gray spots appear, and on cloth it shall be sufficiently heavy to completely conceal the weave. On horizontal surfaces not less than 12 gallons of asphalt or tar shall be used for each 100 square feet of finished work, and on vertical surfaces not less than 15 gallons shall be used.

At the edges of the membrane and at any points where it surrounds such appurtenances as drains or pipes, suitable provisions shall be made to prevent water from getting between the waterproofing and the concrete surface.

All flashing at curbs and against girders, spandrel walls, etc., shall be done with separate sheets lapping the main membrane not less than 12 inches. Flashing shall be closely sealed either with a metal counterflashing or by embedding the upper edges of the flashing in a groove poured full of joint filler.

Joints which are essentially open joints but which are not designed to provide for expansion shall first be caulked with oakum and lead wool and then filled with hot joint filler.

Expansion joints, both horizontal and vertical, shall be provided with approved water stops in accordance with details on the plans and in section 616. The membrane shall be carried continuously across all expansion joints.

At the ends of the structure, membrane shall be carried well down on the abutments and suitable provision made for all movement.

615.04 Membrane Waterproofing with Mortar Protection. Waterproofing membrane to be protected with mortar shall be constructed in all particulars in accordance with the requirements of subsection 615.03.

Every part of the membrane, except on undercut surfaces (the underside of parts of the structure the surface of which

makes an angle of less than 90 degrees with a horizontal plane), shall then be covered with a course of reinforced mortar.

This course shall have a nominal thickness of 2 inches and shall be reinforced with welded wire fabric of 6-inch mesh and No. 12 gage, or its equivalent, placed so as to lie midway between the top and bottom surfaces of the mortar. The top surface of the mortar course shall be troweled to a smooth, hard finish. The protective mortar course shall be cured by burlap help in close surface contact and kept wet for 72 hours.

On undercut surfaces the membrane shall be protected with a layer of asphalt roll roofing laid in hot asphalt or tar instead of the mortar covering. The bituminous material used for this purpose shall be the same as that used in mopping the membrane.

615.05 Membrane Waterproofing with Asphalt Plank Protection. Waterproofing membrane to be protected with asphalt plank shall be constructed in accordance with the requirements of subsection 615.03.

The membrane shall then be covered with asphalt plank. The plank shall be laid in regular, straight courses indicated on the plans. Whole planks shall be used in all cases except as otherwise required for closures and for fitting around openings and obstructions. Closing and trimming pieces shall be cut carefully to size. Before the planks are laid, all surplus talc or other powder shall be removed from them with a stiff brush or broom. Each piece shall be laid in a mopping of hot asphalt or tar and the edges and ends of pieces in place shall be coated with the hot asphalt or tar before another piece is placed against them. Each individual piece shall be pressed tightly against the piece next to it and the completed work shall have a uniform, smooth surface without open joints.

615.06 Defective Work. Any membrane waterproofing that is found to leak at any time prior to the final acceptance of the contract shall be made watertight at the sole expense of the Contractor.

as

Method of Measurement 615.07 The quantity to be paid for will be the number of square yards of waterproofing of the several kinds, completed and accepted.

If a lump sum payment is to be made, measurement will be in accordance with subsection 109.01.

Basis of Payment 615.08 The quantities, determined as provided above, will be paid for at the contract price per unit of measurement, respectively, for each of the particular pay items listed below that is shown in the bid schedule, which price and payment will be full compensation for the work prescribed in this section.

Payment will be made under: Pay item

Pay unit 615 (1) Membrane waterproofing (asphalt)

Square yard. 615(2) Membrane waterproofing (tar) Square yard. 615 (3) Membrane waterproofing

(asphalt) with mortar protection

Square yard. 615 (4) Membrane waterproofing (tar) with mortar protection

Square yard. 615 (5) Membrane waterproofing

(asphalt) with asphalt plank protection

Square yard. 615 (6) Membrane waterproofing (tar)

with asphalt plank pro-
tection

Square yard. 615(7) Membrane waterproofing ( ) Lump sum.

Section 616.-WATER STOPS

Description 616.01 This work shall consist of water stops formed of rubber, plastic compounds or sheet copper furnished and placed in expansion and construction joints in reasonably close conformity with these specifications and at the locations shown on the plans or ordered by the Engineer.

Materials

616.02 Materials shall conform to the requirements of the following subsections:

Copper waterstops
Rubber waterstops
Plastic waterstops

705.06 705.07 705.08

Construction Requirements

616.03 Copper Waterstops. Copper sheets for water stops shall be of the thickness, weight, width, and shape shown on the plans or ordered by the Engineer. The sheet copper in each joint, if not a single sheet, shall be segment pieces connected by soldering joints into a continuous watertight unit.

616.04 Rubber Waterstops. Splices shall be made watertight by vulcanizing or mechanical means, in accordance with the manufacturer's instructions. If splices are used, the Contractor shall make at least one preliminary field splice sample for testing by the Engineer. No splicing shall be done until tests indicate a tensile strength of at least 50 percent of the reported tensile strength of the unspliced rubber waterstop.

616.05 Plastic Waterstops. Splices shall be made watertight by a heating process, without damage to he plastic, in accordance with the manufacturer's instructions. Preliminary splice samples shall be made and tested in accordance with subsection 616.04 and no splices shall be made in the work until a tensile strength for splices of at least 80 percent of that reported for unspliced plastic waterstops is indicated by tests.

616.06 Placing Waterstops. Waterstops shall be carefully placed and supported at the locations shown on the plans. Precautions shall be taken so that the waterstops shall be neither displaced nor damaged by construction operations or other means. All surfaces of the waterstops shall be kept free from oil, grease, dried mortar, or any other foreign matter while the waterstop is being embedded in concrete. Means shall be used to insure that all portions of the waterstop designed for embedment shall be tightly enclosed by dense concrete.

Method of Measurement 616.07 Unless a pay item for waterstops appears in the bid schedule, no measurement or direct payment will be made for the work of this section, but any such work will be considered as included for payment under section 601.

Except as provided for in subsection 109.01, no measurements will be made for lump sum payment when so designated in the bid schedule.

Measurements of waterstops to be paid for by designated units will be made of the specified material acceptably placed as directed.

Basis of Payment 616.08 The quantities, determined as provided above, will be paid for at the contract price per designated unit of measurement or lump sum as shown for each of the pay items listed below that appears in the bid schedule. Such price and payment will be full compensation for the work of this section.

If none of the pay items listed below appear in the bid schedule, no direct payment will be made, but the work will be considered as a subsidiary obligation of the Contractor, included for payment in the contract price for various classes of concrete.

Payment will be made under: Pay item

Pay unit 616(1) Copper waterstop

Square foot. 616 (2) Copper waterstop, width

Linear foot. 616(3) Copper waterstop

Lump sum. 616 (4) Rubber waterstop

Square foot. 616 (5) Rubber waterstop, width

Linear foot. 616 (6) Rubber waterstop

Lump sum. 616 (7) Plastic waterstop

Square foot. 616 (8) Plastic waterstop, width

Linear foot. 616(9) Plastic waterstop

Lump sum. Letter suffixes will be added to the item numbers and the item name amended to provide for linear foot bid prices when waterstops are to be furnished in more than one width and direct payment made therefor.

Section 617.-STRUCTURAL-PLATE PIPE,
PIPE-ARCHES, AND ARCHES

Description 617.01 This work shall consist of structural-plate pipe, pipe-arches, and arches of the sizes, gages, and dimensions shown on the plans, furnished and installed at such places as are designated on the plans or by the Engineer in reasonably close conformity with these specifications and the lines

« PreviousContinue »