711Riprap

711.01 DESCRIPTION. Furnish and place riprap in accordance with these specifications and in conformity to lines, grades, and thickness shown on the plans or as directed. 711.02 MATERIALS. Furnish stone or recycled concrete riprap from an approved source. Stone riprap shall be listed in the Approved Materials List. Stone riprap shall not disintegrate upon exposure to the elements or be easily broken from handling, and shall be reasonably free from earth and other foreign materials. When tested in accordance with AASHTO T 85, the solid weight of stone shall be at least 155 pounds per cubic foot (based on bulk specific gravity). The least dimension of any individual stone shall be at least one-third its maximum dimension. Each shipment of stone shall be reasonably well graded within the specified limits. Recycled concrete may be used as riprap unless otherwise indicated in 711.02.1, provided its solid weight is at least 140 pounds per cubic foot (based on bulk specific gravity) and free of protruding reinforcement. Stockpiles of recycled concrete shall be source approved prior to use and kept separate from other materials. Stockpiles shall be uniform and free of soil, debris, excessive amounts of asphalt materials, and foreign matter. Once a stockpile has been approved as an acceptable source of material, do not add material without further approval. Visually inspect riprap at the source, project site, or both to control gradation. Any difference of opinion between the engineer and contractor will be resolved by checking the gradation of two random truckloads (or equivalent size samples). Furnish equipment, labor, and a sorting site at no direct pay. 711.02.1 Riprap: Riprap shall be reasonably well graded and in compliance with Table 711-1. Table 711-1 Riprap Class 1 Stone Size, lb Spherical Diameter, foot 2 Percent of Stone Smaller Than 2 lb 0.75 0.51 0.38 0.30 0.22 40-100 15-50 0-15 10 lb 0.88 0.65 0.51 0.41 50-100 15-50 0-15 30 lb 1.24 0.94 0.74 0.51 42-100 15-50 0-15 55 lb 3 1.50 1.11 0.88 0.63 42-100 15-50 0-15 130 lb 3 2.00 1.46 1.17 0.79 45-100 15-50 0-15 250 lb 3 2.50 1.83 1.46 1.00 45-100 15-50 0-15 440 lb 3 3.00 2.23 1.76 1.17 40-100 14-50 0-15 1000 lb 3 4.00 2.91 2.31 1.55 45-100 10-50 0-15 1 The stone size used to define the Riprap Class is the minimum median stone size for the stone class. The minimum thickness of a riprap layer shall be no less than the spherical diameter of the maximum stone size in the Riprap Class. 2 Spherical diameters of riprap classes up to 30 lb are based on a solid stone weight of 140 lb/cu ft. Spherical diameters of riprap classes above 30 lb are based on a solid stone weight of 155 lb/cu ft. 3 Recycled portland cement concrete s hall not be used in these riprap classes. 711.02.2 Geotextile Fabric: Geotextile Fabric shall comply with 1019.01. 711.03 CONSTRUCTION REQUIREMENTS. 711.03.1 Riprap: Grade slopes or areas on which riprap is to be placed to the required section. Place riprap on the prepared slope or area in a manner which will produce a reasonably well-graded mass of stone with a minimum practicable percentage of voids. Place the entire mass of stone in conformance with the lines, grades, and thickness in one operation without displacing underlying material. Placing of riprap in layers, or dumping into chutes, or by similar methods likely to cause segregation will not be permitted. When placement in water currents is required, make drift checks and place riprap in such manner as to compensate for drift. Furnish necessary facilities, equipment, and personnel for checking riprap depth and distribution. 711.03.2 Filter Stone: When specified, place filter stone on the prepared slope or area before placement of riprap. When filter stone is placed underwater, free dumping will not be permitted. Use controlled methods for underwater placement using bottom dump buckets or wire rope baskets lowered through the water to the point of placement. If placement in strong water currents is required, place riprap promptly after placement of filter stone. Unless shown otherwise on the plans or directed, filter stone shall be Riprap Class 10 lb or less. 711.03.3 Geotextile Fabric: When specified, place geotextile fabric on the prepared slope or area in accordance with 203.11.3 before placement of riprap. Take care not to damage the geotextile fabric when placing riprap. Do not place riprap by rolling riprap down slope, or dropping riprap from extreme heights, or by similar methods likely to damage geotextile fabric. Repair damaged geotextile fabric in accordance with 203.11.3 or replace as directed. 711.04 MEASUREMENT. Riprap and filter stone may be measured on a square yard, cubic yard, or weight basis as specified. When measured on a square yard basis, the quantity measured will be that actually placed to the limiting dimensions shown on the plans or as directed by the engineer. When measured on a cubic yard basis, measurement will be made in vehicles at the point of delivery on the project in accordance with 109.01. When measured on a weight basis, the pay unit will be per ton (2000 pounds). When riprap is delivered by vehicles or railroad cars, measurement will be based on certified weight tickets furnished by the contractor. When riprap is delivered by barge, measurement will be made by calculation from barge displacement, based on water weighing 62.4 pounds per cubic foot. Geotextile fabric will be measured by the square yard of covered area in place. No measurement will be made for excavation or backfilling. 711.05 PAYMENT. Payment for riprap and geotextile fabric will be made at the contract unit prices. Filter stone will be paid for as riprap. Payment will be made under: Item No. Pay Item Pay Unit