Summary

This is a specification document issued by the Louisiana Department of Transportation and Development (DOTD) for aggregate riprap products used in maintenance activities. The specification establishes standards for three riprap classes: Product ID 51700 (30 lb), Product ID 51290 (55 lb), and Product ID 51001 (130 lb). Stone riprap must be sourced from the Approved Materials List – Aggregates and meet durability requirements, including resistance to disintegration and breakage. Materials must have a minimum solid weight of at least 155 pounds per cubic foot when tested in accordance with AASHTO T 85, with the least dimension of any individual stone being at least one-third its maximum dimension. The specification document, dated September 26, 2019, provides detailed gradation requirements for each riprap class, including stone size ranges, spherical diameters, and acceptable percentages of stones smaller than specified sizes.

The specification establishes quality and sizing standards for riprap materials rather than pricing terms or procurement details. Each riprap class is defined by a minimum median stone size and includes multiple gradation sizes within that class. The minimum thickness of a riprap layer shall be no less than the spherical diameter of the maximum stone size in the respective Riprap Class. Spherical diameter calculations for riprap classes up to 30 lb are based on a solid stone weight of 140 lb/cu ft, while classes above 30 lb are based on a solid stone weight of 155 lb/cu ft. Stone or recycled concrete riprap must be free from earth and other foreign materials to meet DOTD specifications.