815Riprap and Slope Paving

815.01Description. This work consists of furnishing and placing a protective covering

of erosion resistant material including geotextile fabric, where shown on the plans for pier foundation protection, slope, or ditch protection. This work shall be in accordance with these specifications and in reasonably clos e conformity with the lines, grades and dimensions shown on the plans or established.

815.02Materials. Materials for riprap and slope paving shall conform to the following

Geotextile shall meet the requirements of Subsection 714.13. Aggregate for loose ripr ap, stone riprap for foundation protection, or that to be grouted shall consist of field stone, broken concrete, or rough, unhewn quarry stone as nearly 1059 Section 815 Section 815 rectangular in section as is practicable. The stone shall be dense, free of clay or shale seams, resistant to the action of air and wate r, and suitable in all other respects for the purpose intended. Quality requirements for rock to be furnished under these specifications will come from a pre-approved source or be visually approved prior to use. Hydraulic cement concrete aggregates, unless otherwise specified, shall conform to the applicable requirements of Section 703. Cloth sacks for concrete riprap in bags shall be of suitable cloth or jute that will hold the concrete mixture without leakage when handled . The sacks shall be of uniform size and dimensions, approximately 19½ x 36 inches m easured inside the seams when the sack is laid flat. Sound reclaimed cloth sacks meeting the specified requirements may be used. Paper sacks for concrete riprap in bags shall be a polyester fiber type of scrim reinforced paper. The top and bottom of the sacks shall have a pasted valve. When filled, they shall measure approximately 13 inches wide, 20 inches long, and five inches thick. Perforations shall be overall on one-inch centers with a diameter of 3/32 inch to 1/8 inch per hole. Each bag shall fill a space of approximately 0.71 cubic feet with 38 bags required per cubic yard. Pre-packaged riprap will be accepted on certification from the manufacturer. Stones for riprap, of the size specified, shall meet the requirements of Subsection 705.04. Material used for sediment control stone sh all be crushed stone or gravel meeting the requirements of Subsection 703.03 for Size No. 57.

815.03Construction Requirements

.1--Construction Details. Prior to the construction of riprap or slope paving, the

slopes or ground surface shall be shaped to lines and grades indicated on the plans or directed, and shall be thoroughly compacted by the use of mechanical or hand tamps. Unless otherwise stipulated or directed, slopes shall not be steeper than the natural angle of repose of the material upon which riprap is to be constructed. The outer edges and the top of the riprap or slope paving where the construction terminates shall be formed so that the surface of the riprap or slope paving will be embedded and even with the surface of the adjacent slope or ground, and the bottom of the riprap or slope paving shall be placed at least two feet below the natural ground surface unless otherwise directed. All riprap or slope paving shall be starte d at the bottom of the slope and constructed upward. No grout, bag riprap, or slope paving shall be placed during freezing weather or while there is frost on the ground. Prepackaged riprap in paper bags shall be immediately soaked with water after placement to ensure hydration of the cement. In hot or dry weather grout and bag riprap shall be kept moist and protected from the sun for at least three days after placing. Replacement will be required if the bags do not set up to form a solid mass. Slope paving shall be cured in accordance with the provisions of Subsection 815.03.7.4.

.2--Installation of Geotextile. When required by the contract, geotextile shall be

placed in the manner and at locations shown on the plans. The area to receive the geotextile 1060 Section 815 Section 815 shall be prepared to a relatively smooth co ndition free of obstructions, depressions and debris. The geotextile shall be placed loosely without wrinkles or creases with the long dimension perpendicular to the channel. The strips shall be placed to provide a minimum overlap of 18 inches. Securing pins with washers shall be inserted through both strips of overlapped geotextile at mid-point and not greater than two foot intervals. Additional pins shall be installed throughout the geotextile as necessary to prevent any slippage. The geotextile shall be placed so that the upstream strip overlaps the downstream strip and the higher slope strip overlaps the lower strip. Each securing pin shall be pushed through the geotextile until the washer bears against the geotextile and secures it firmly. The geotextile shall be protected from contam ination and damage during installation and placement of the specified cover material. Ri prap shall not be dr opped from a height greater than three feet. Contaminated geotextile shall be replaced, and damaged geotextile shall be repaired or replaced as directed at no cost to the Department. The geotextile shall be covered with a layer of the speci fied material within 14 calendar days after placement. Geotextile not covered within this time period shall be removed and replaced at the Contractor's expense if damage or deterioration is ev ident, as determined by the Engineer.

.3--Loose Riprap. The stones shall be placed upon a slope not steeper than the

natural angle of repose of the slope material. The stones shall be laid with close joints. The courses shall be laid from the bottom of the bank upward with the larger stones being placed in the lower courses. Interstices shall be filled with smaller stones and spalls.

.4--Grouted Riprap. Grout for grouted riprap shall consist of one part of hydraulic

cement and three parts of approved sand thoroughly mixed with water to produce grout having a thick, creamy consistency. The stones shall be of the size designated in the bid schedule of the contract and shall be placed in the same manner as specified for loose riprap. Care shall be taken during placing to keep earth or sand from filling the spaces between the stones. After the stones are in place, the spaces between them shall be completely filled with grout from bottom to top and the surface swept with a stiff broom.

.5--Stone Riprap for Foundation Protection. Stone riprap for pier and abutment

protection shall range in size up to derrick stone and shall be graded from coarse to fine in such manner as to produce a minimum of voids. It shall be deposited where directed and stone deposited contrary to directions will be considered wasted and will not be paid for.

.6--Concrete Riprap in Bags. Concrete riprap in cloth or jute bags shall consist of

Class "D" concrete in approved bags and placed in conformity with contract requirements. Each bag shall be filled with approximately one cubic foot of concrete, securely tied, and immediately placed in the work and lightly tr ampled to cause them to conform with the slope or section required with adjacent bags in place. Unless otherwise specified in the contract, the bagged concrete shall be packed in such a manner as to give a reasonably uniform thickness of approximately 12 inches and shall be lapped and staggered as directed. 1061 Section 815 Section 815 Pre-packaged riprap in paper bags shall be filled with kiln- dried mixtur e of hydraulic cement and sand, or cement, sand and gravel with a ratio of three parts sand or sand and gravel to one part hydraulic cement. The bags shall be placed to conform with the slope or required section and with adjacent bags in place. The bags shall be lapped and staggered as directed. When shown on the plans, pipe headwalls shall be constructed of concrete riprap in bags in accordance with these specifi cations and the plan details. In this construction, it is essential that the successive tiers are securely "keyed" by lapping. The bags shall be lapped one-half their length, when practicable.

.7--Slope Paving. Concrete slope paving shall be constructed in a single layer in

conformity with the design dimensions and details indicated on the plans.

.7.1--Forms. Forms shall be wood or metal of sufficient strength to withstand the

pressure of the concrete without bulging. They shall be adequately and securely staked true to line and grade.

.7.2--Mixing and Placing Concrete. Unless otherwise stipulated, the concrete used

in this construction shall be Class "C" Concrete, mixed and placed in accordance with the provisions and requirements of Section 804, except that volumetric batching may be used. Mixers of less than one bag rated capacity shall not be used.

.7.3--Finishing. After spreading, the concrete shall be tamped and puddled until it

is compact and sufficient mortar has been flus hed to the surface so that it can be finished smooth with a wooden float. All edges shall be neatly edged using an approved short radius sidewalk edge.

.7.4--Curing. After the concrete has set sufficiently, the surface shall be protected

from premature drying by covering as soon as possible with a satisfactory material such as wetted burlap or wetted cotton mats and kept moist for a minimum of three days, or cured by other approved methods. Other approved methods include liquid membrane compound as set out in Subsection 713. 01.2 and applied in accordance with the provisions of Subsection 501.03.20, except that approved hand spray methods will be acceptable, and white polyethylene sheeting conforming to the requirements of Subsection 713.01.3 and applied in accordance with the provisions of Subsection 501.03.20. Both liquid membrane compound and polyethylene sheeting shall be maintained in place and intact for a minimum period of three days.

.7.5--Soil Sterilization . Prior to placing slope pavement, the areas beneath the

pavement shall receive soil sterilization treatment as set out in Subsection 616.03.2.

.8--Cleaning Up. Upon completion of the work, th e surface of the riprap or slope

paving shall be cleaned, surplus material and debris removed and disposed of as directed, and the site of the work left in a neat presentable condition.

815.04Method of Measurement. Loose riprap will be measured in square yards or tons,

as specified. Sediment control stone will be measured by the cubic yard (LVM) or ton, as specified. The pay area will be determined by using the outside dimensions of the area covered as dir ected. Tons or fraction thereof will be determined by railway weights or 1062 Section 815 Section 815 other satisfactory and approved weighing met hods. Stone placed contrary to directions will not be paid for. Measurement or payment will not be made for grout, and the cost thereof shall be included in the compensation for grouted riprap. Concrete riprap in cloth or jute bags will be measured in cubic yards as the quantity received or manufactured at the site of the work and acceptably placed in bags as required. From the amount received or manufactured at the site, there will be deducted all excess determined by the Engineer to have been wasted or placed to unauthorized dimensions. The cubic yards of pre-package riprap in paper bags will be determined from the actual count of bags placed and accepted based on 38 bags per cubic yard. Slope paving will be measured by the cubic yard computed using the dimensions shown on the plans. If authorized revisions are made in the finish grade or the configuration of the slope pavement, computations will be made considering the changed dimensions. Geotextile complete in place and accepted will be measured by the square yard of surface

area covered. Any overwidth of material installed and additional material required for laps

or sewing will not be measured. No separate payment shall be made for shipping, handling,

storage, protection, fabrication, securing pins, or installation; the cost of which shall be

included in the contract price for geotextile fabric.

815.05Basis of Payment. Loose riprap, measured as prescribed above, will be paid for

at the contract unit price per square yard or ton. Sediment control stone, measured as

prescribed above, will be paid for at the contract unit price per cubic yard or ton. Grouted

riprap, measured as prescribed above, will be paid for at the contract unit price per square

yard. Concrete riprap in bags and concrete slope paving, measured as prescribed above,

will be paid for at the contract unit price per cubic yard. Geotextile, measured as prescribed

above, will be paid for at the contract unit price per square yard. Such payment shall be

full compensation for completing the work.

Payment will be made under:

815-A: Loose Riprap, Size - per square yard or ton

815-B: Grouted Riprap - per square yard

815-C: Concrete Riprap in Bags - per cubic yard

815-D: Concrete Slope Paving - per cubic yard

815-E: Geotextile under Description, Type * , AOS * - per square yard

815-F: Sediment Control Stone - per cubic yard or ton

* When not designated, see Subsection 714.13.. 1063