SECTION 579 - STRUCTURAL SLAB RECONSTRUCTION PREPARATION
579-1 DESCRIPTION. The work shall consist of initially preparing an existing structural slab for
reconstruction. Generally, this work shall entail the removal of concrete to the depths, and at the locations, required by the contract documents.
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NEW YORK STATE DEPARTMENT OF TRANSPORTATION Sections 200 - 599 STANDARD SPECIFICATIONS (USC) January 1, 2026 Volume 2
579-1.01 Structural Slab Scarification
A.This work shall consist of removing the top surface of structural slab concrete. Removal shall be done by scarification to the following limits, unless a greater depth is indicated on the plans:
1.Minimum of 1/4 inch
2.Maximum of 1/2 inch
B.After scarification, if a structural slab survey is required, the surface to be surveyed shall be cleaned sufficiently to allow the survey to be taken. The Engineer will determine if the surface is cleaned sufficiently to allow performance of the necessary delamination and potential survey tests.
C.All removed materials shall be transported from the work site and disposed of or disposed of in an area on the job site approved by the Engineer.
579-1.02 Exposure of Reinforcing Bars
A.Definitions
1.Bar Mat. That combination of transverse and longitudinal reinforcing steel placed with the structural slab to absorb stresses. Structural slabs generally contain two bar mats; an upper mat and a lower mat.
2.Upper Mat. That bar mat closest to the existing top surface of the structural slab. Only the upper mat is relevant to this work, except in localized areas.
3.Localized Area. An area where full depth removal and subsequent patching will be done as part of this work. For the work of this section a localized area shall not exceed 25 sf. The sum of the localized areas shall comprise no more than five percent (5%) of the structural slab area to be prepared.
B.The work shall consist of structural concrete removal from the periphery of the upper mat reinforcing bars to provide a minimum clearance of 1 inch between the reinforcing bar surface and the remaining concrete surface. In addition, the Engineer may order the removal of other concrete. (Refer to 579-3 Construction Details).
C.All work performed under the requirements of this subsection shall not extend beyond a plane which is 5 inches below the original top of slab, except for localized areas.
D.Removed materials shall be disposed of in accordance with 579-1.01C.
579-2 Materials
Concrete 501 & MP 501-2 Table 2 Quilted Covers (for curing concrete) 711-02 Plastic-Coated Fiber Blankets (for curing) 711-03 NOTES:
1.Materials Procedure (MP) 501-2 Mix Design and Approval Procedure for Performance Engineered Mixtures – Structural Concrete.
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NEW YORK STATE DEPARTMENT OF TRANSPORTATION Sections 200 - 599 STANDARD SPECIFICATIONS (USC) January 1, 2026 Volume 2
2.For quantities of 5 cy of total project placement, or less, automatic batching equipment will not be required.
579-2.01 Equipment
A.Power Operated Scarifier. The specific equipment the Contractor proposes to use shall be approved by the Engineer prior to use. Power bush hammers, or other impact type devices which indent or pulverize the surface shall not be allowed under any circumstances.
B.Pneumatic Hammers and other equipment. These shall be subject to the Engineer's approval prior to use. Pneumatic hammers shall meet the requirements of §580-3.02
C.Other Equipment. All other equipment proposed for use shall be approved by the Engineer prior to actual employment in the work.
579-3 CONSTRUCTION DETAILS. The Contractor shall exercise care during the execution of the
work to avoid damaging or loosening material that is to remain. All damage caused by the Contractor's operations to material that is to remain shall be repaired, or the material replaced as determined by the Engineer. All repair and replacement work shall be done in a manner satisfactory to the Engineer.
579-3.01 Structural Slab Scarification. Scarification of designated areas shall be accomplished with a
power operated scarifier. Inaccessible areas will be scarified with pneumatic hammers.
579-3.02 Reinforcing Bar Exposure
A.Concrete shall be removed from the uppermost reinforcing bars of the structural slab to the limits designated by §579-1.02B. The Contractor may remove concrete, to the designated minimums, from around both sets of bars in the upper mat.
B.If concrete is removed only from the periphery of the uppermost bar, removal shall be done in accordance with those details indicated on the plans.
C.If the Contractor chooses to remove concrete from the periphery of both bars of the upper mat, or if the Engineer determines that:
1.The lower bar is corroded; OR
2.The concrete around the lower bar is deteriorated; OR
3.Delamination extends to the level of, or below, the lower bar; OR
4.The lower bar is debonded; then the concrete shall be removed from the periphery of the lower bar in accordance with the details indicated on the plans.
D.At locations where deteriorated concrete extends beyond the minimum removal limits, the Engineer will order its removal. The Engineer will be the sole determiner of what constitutes deteriorated concrete. This ordered removal shall be part of this work, except that removal of deteriorated concrete below the limit established by §579-1.02C, shall be part of this work only within the limits of localized areas. Locations where concrete is removed beyond minimum limits, lacking specific orders from the Engineer directing such removal, will be designated as damage
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NEW YORK STATE DEPARTMENT OF TRANSPORTATION Sections 200 - 599 STANDARD SPECIFICATIONS (USC) January 1, 2026 Volume 2 locations. All damage locations shall be repaired in a manner satisfactory to the Engineer, at no additional cost to the State.
E.At localized areas, the Engineer may order concrete removal below the plane established by §579- 1.02C. When such removal reaches the uppermost bar of the lower reinforcing bar mat, removal shall be continued until full depth removal is achieved.
F.Care shall be exercised when removing concrete to avoid damaging reinforcement, or other materials, which are to remain in place. Reinforcing steel damaged by the Contractor's operations shall be replaced with new reinforcing steel of the same size, appropriately spliced. Reinforcing steel splices shall be made in accordance with the details shown on the plans. Other materials designated to remain in place, which are damaged by the Contractor's operations, shall also be replaced.
579-3.03 Full Depth Patches. Refer to the details indicated on the plans.
A.Immediately prior to placing new concrete, the reinforcing bars and the edges of the existing structural slab, which will be in contact with new concrete, shall be blast cleaned. Forms shall be drawn tightly. Preparation and formwork shall be approved by the Engineer prior to any concrete placement. “After blast cleaning has been accepted, thoroughly wet the structural slab surface and all porous surfaces to be in contact with new concrete for at least 12 hours immediately prior to placement. Remove all standing water with oil-free compressed air, and protect the surface from drying, so the concrete remains in a saturated surface dry condition when placing bonding grout.
B.Concrete shall be placed and consolidated in accordance with the requirements of §555-3.04. The uppermost surface of the concrete patch shall be level with the highest of the surrounding prepared surfaces. The uppermost surface shall be intentionally roughened. The Engineer may require that a coarse textured drag be used on the plastic concrete surface.
C.Concrete shall be cured, in a manner approved by the Engineer, for a minimum of 72 curing hours prior to any other concrete placement work in contact with the curing concrete. A curing hour is defined as any hour, starting from the hour of placement, during which the ambient air temperature at the concrete surface remains at, or above 45°F as measured by a recording thermometer. Curing shall be done by means of quilted covers (§711-02), or plastic coated fiber blankets (§711-03). Quilted covers, if used, shall be kept wet during the entire curing period. The use of curing compounds shall not be allowed.
579-3.04 Hydro-demolition . Hydro-demolition , if approved by the Engineer, shall be subject to the
following:
A.Hydro-demolition Plan. At least two weeks prior to the employment of any hydro-demolition equipment, the Contractor shall submit to the Engineer, for approval, a comprehensive plan for the management of hydro-demolition wastewater. A hydro-demolition plan that proposes wastewater discharge to a sanitary sewer system or sewage treatment facility shall meet the criteria determined by the permitted Publicly-Owned- Treatment-Works (POTW). A hydro-demolition plan that proposes wastewater discharge to a channelized flow or surface water is subject to permitting by State and/or Federal regulatory agencies. The Contractor shall be responsible for obtaining any necessary project-specific permit(s) from State and/or Federal agencies if this option is proposed and is made aware that such approvals may involve significant lead time for approval.
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NEW YORK STATE DEPARTMENT OF TRANSPORTATION Sections 200 - 599 STANDARD SPECIFICATIONS (USC) January 1, 2026 Volume 2 A hydro-demolition plan that proposes wastewater discharge to a concrete reclamation/recycling facility shall require and acceptance letter from the proposed facility that provides specifications on their reclamation/recycling process for concrete wastewater. Comprehensive plans shall include the following information:
1.Method of visible deck contaminant removal, if applicable;
2.Specifications for proposed hydro-demolition equipment (i.e., blast equipment, vacuum trucks, water retention, etc.);
3.Specific erosion and sediment control measures to be implemented as part of the work, including any necessary tarping or sealing to prevent below-deck leaking of process water;
4.Specifications for proposed equipment/methodology to treat and manage wastewater (i.e., settling tanks, containment, filtration, etc.) for turbidity;
5.Specifications for proposed equipment/methodology to treat wastewater (i.e., acid introduction, CO2 injection, etc.) for pH; and
6.Specifications for proposed equipment/methodology to monitor/measure turbidity and pH.
B.Overland Wastewater Discharge. If appropriate onsite location(s) are identified in contract documents or the Contractor is able to utilize a suitable overland area, a hydro-demolition plan proposing to discharge wastewater overland shall be developed in accordance with the Memorandum of Understanding (MOU) between New York State Department of Transportation and the New York State Department of Environmental Conservation dated September 6, 2012. The following MOU criteria apply to any hydro-demolition plan including overland discharge of wastewater:
1.Removal of visible bridge deck contaminants prior to hydro-demolition work;
2.Appropriate erosion and sediment control measures as described in the current New York State Standards and Specifications for Erosion and Sediment Control;
3.pH adjustment of wastewater to levels between 6.5 and 8.5 prior to final discharge;
4.Turbidity treatment of wastewater to 50 Nephelometric Units (NTUs) or less prior to final discharge;
5.Prevention of visible particle layers on land or vegetation at point of final wastewater discharge; and
6.Prohibition of the use of water treatment chemicals, such as flocculants, except for pH treatment. The Contractor shall conduct testing, a minimum of twice daily, for both pH and turbidity of the wastewater prior to discharge. These measurements shall be tabulated as the hydro-demolition work progresses and provided to the Engineer on a daily basis.
C.Adherence. Hydro-demolition wastewater plans will be approved by the Engineer within 10 days of a complete and accurate submission by the contractor. If plans are not being followed, the Contractor shall immediately stop hydro-demolition operations until the conditions are corrected.
D.Debris Removal. All hydro-demolition debris shall be removed in a manner that prevents re- bonding of the debris to the concrete surface. All debris which re-bonds shall be removed in a manner satisfactory to the Engineer at no cost to the State. Material designated to be left in place, which is damaged by re-bonded debris removal work, shall be repaired in a manner satisfactory to the Engineer at no cost to the State.
579-4 Method of Measurement
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NEW YORK STATE DEPARTMENT OF TRANSPORTATION Sections 200 - 599 STANDARD SPECIFICATIONS (USC) January 1, 2026 Volume 2
579-4.01 Structural Slab Scarification. The work will be measured as the number of square feet stated
in the Estimate of Quantities shown on the plans. Except to allow for progress payments, no field measurements will be taken. Field measurements for progress payments shall not exceed the Estimate of Quantities figure.
579-4.02 Reinforcing Bar Exposure. The work will be measured as the number of square feet of
concrete removed. Quantities will be determined from field measurements.
579-5 BASIS OF PAYMENT. The unit price bid per square foot shall include the cost of all labor,
materials and equipment necessary to complete the work. No additional payment will be made for removals, repairs or replacements made necessary due to the Contractor's operations.
579-5.01 Reinforcing Bar Exposure. The unit price bid per square foot shall include the cost of all
labor, material and equipment necessary to perform full depth patching in localized areas. Full depth concrete removal, and full depth patching, in excess of the limits established for localized areas will be paid for as extra work. Payment will be made under: Item No. Item Pay Unit 579.01 Structural Slab Scarification Square Foot 579.02 Reinforcing Bar Exposure Square Foot
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Source: Standard Specifications (US Customary Units), 2026 (Jan) Edition. Pages 620–625 of 1,489. View official source ↗