507.01 507-1 SECTION 507 SLOPE AND DITCH PAVING DESCRIPTION
507.01 This work consists of the construction of slope and ditch paving per these specifications
and in conformity with the lines and grades shown on the plans or established. MATERIALS
507.02 Concrete Slope and Ditch Paving . Concrete shall conform to the requirements of
Section 601. Concrete shall be Macro Fiber -Reinforced Class B Concrete.
507.03 Dry Rubble Slope and Ditch Paving . Stone shall conform to the material requirements
of subsection 506.02. Size of stone and total thickness of paving shall be as shown on the plans.
507.04 Grouted Rubble Slope and Ditch Paving . Stone shall conform to the material
requirements of subsection 506.02. Size of stone and total thickness of paving shall be as shown on the plans. Mortar shall consist of one part portland cement and three parts of fine aggregate by volume thoroughly mixed with as much water as is necessary to obtain the required consistency. Materials shall meet the requirements specified in the following subsection s: Hydraulic Cement 701.01 Fine Aggregate 703.01 Water 712.01 Mortar shall be used within 45 minutes after mixing and shall not be re- tempered. Class B concrete, conforming to the requirements of Section 601, may be substituted for mortar.
507.05 Grouted Riprap Slope and Ditch Paving . Concrete mortar for grouted riprap slope
and ditch paving shall meet the requirements of Section 601 and the following: Table 507 -1 GROUTED RIPRAP CONCRETE MORTAR REQUIREMENTS Field Compressive Strength (28 days) (Not a specification requirement) 2000 psi Minimum Cement Content 560 lb/cu yd Air Content 6-9% Slump, AASHTO Designation T -119 5-9 inches Fine Aggregate, AASHTO M -6 65-75% Coarse Aggregate, AASHTO M -43 3/8" nominal maximum size Polypropylene Fibers (1" fiber length or equivalent) 1.5 lb/cu yd 507.06 507-2 Riprap stone shall conform to the quality requirements of subsection 506.02 and the classification and gradation requirements specified in the following table: Table 507-2 CLASSIFICATION AND GRADATION OF ROCK FOR GROUTED RIPRAP Riprap Designation Percent Smaller Than Given Size by Weight Intermediate Rock Dimension, Inch d50 = 24" (Type HG) 100 30 d50 = 24" (Type HG) 50 - 70 24 d50 = 24" (Type HG) 0 - 5 18 d50 = 18" (Type MG) 70 - 100 21 d50 = 18" (Type MG) 50 - 70 18 d50 = 18" (Type MG) 0 - 5 12
507.06 Asphalt Slope and Ditch Paving . The mixture used shall conform to the
requirements for the asphalt pavement used on the project. CONSTRUCTION REQUIREMENTS
507.07 Paving thickness shall be as specified on the plans. In ditch construction, the
excavated areas adjacent to the paving that are not occupied by the paving shall be refilled to the level of original ground with acceptable material and thoroughly tamped. Excavation for toe or cut -off walls shall be made to the neat lines of the wall. Allowance will not be made for work outside the neat lines.
507.08 Concrete Slope and Ditch Paving. Concrete shall be mixed, placed and cured per
Section 601. Unsuitable soil shall be removed and replaced with a suitable soil as designated by the Engineer. Where the thickness of concrete lined ditch as shown on the plans is less than 4 inches, this concrete slope and ditch paving shall be installed with slip -form machine, except for the following:
1.Where it is deemed impossible to construct the ditch lining by the slip -form method, the lining shall be hand formed and the thickness shall be at least 1 inch greater than the thickness shown on the plans.
2.The Contractor may use hand method of placement in lieu of the slip -form method, provided the thickness of this hand -placed lining is at least 1 inch greater than the thickness shown on the plans. Where the thickness of concrete lined ditch as shown on the plans is 4 inches or greater, the Contractor will be permitted to place the material with a slip -form machine or by hand method. 507.09 507-3 507.09 Dry Rubble Slope and Ditch Paving. Stones shall be placed with close joints, which shall be broken to minimize straight construction joints. The stones shall be placed to give the appearance of plating the fill slope. Larger stones shall be placed on the lower courses. Open joints shall be filled with spalls. Oversize stones and protrusions that present a safety hazard will not be permitted.
507.10 Grouted Rubble Slope and Ditch Paving. Stones shall be laid as specified in subsection
507.09, with care to prevent earth and sand filling the joints. Joints shall be filled with grout from bottom to top and the surfaces swept with a stiff broom. Grouting shall not be done in freezing weather. In hot, dry weather, the work shall be protected and kept moist for at least three days after grouting, or clear membrane curing compound may be used.
507.11 Grouted Riprap Slope and Ditch Paving. All placement of concrete mortar shall be in
conformance with subsection 601.12 with the following exceptions:
1.All concrete mortar shall be delivered by means of a low pressure (less than 10 psi) grout pump using a 2 -inch diameter nozzle.
2.Full depth penetration of the concrete mortar into the riprap shall be required. To achieve this, a pencil vibrator shall be used.
3.The top 6 inches of the rock layer shall be left exposed.
4.After placement, all exposed rocks shall be cleaned with a wet broom.
5.All concrete mortar between rocks shall be finished with a broom finish.
6.Weep holes constructed of 1 1/2- inch or 2 -inch PVC pipe shall be installed when required by the Engineer. The PVC pipe shall be cut flush with the surrounding grout. To alleviate plugging, the PVC pipe shall be pushed into the bedding, or if bedding is not required, under the rock layer. The PVC pipe shall be wrapped in a coarse geotextile fabric filled with 1 1/2- inch rock.
7.All concrete mortar shall be sprayed with a clear liquid membrane -curing compound as specified in subsection 601.13(b).
8.Cold weather curing shall be per subsection 601.13(d).
507.12 Asphalt Slope and Ditch Paving. The asphalt mixture shall be properly shaped to the
required cross section and thoroughly compacted. A fog seal shall be placed on the exposed surfaces of the paving at the rate of approximately 0.1 gallon per square yard. Material for fog seal shall be Emulsified Asphalt (CSS -1) or as designated. METHOD OF MEASUREMENT
507.13 Asphalt slope and ditch paving will be measured by the ton and shall include asphalt.
Slope and ditch paving of the other various types will be measured by the cubic yard by the method of average end areas based on dimensions shown on the plans or ordered. When the plans call for concrete lined ditch less than 4 inches thick, but the actual thickness placed is greater than the plan thickness, measurement and payment will be made only for the thickness shown on the plans. 507.14 507-4 BASIS OF PAYMENT
507.14 The accepted quantities will be paid for at the contract unit price for the various
items below that appear in the bid schedule. Payment will be made under: Pay Item Pay Unit Concrete Slope and Ditch Paving Cubic Yard Concrete Slope and Ditch Paving (Reinforced) Cubic Yard Dry Rubble Slope and Ditch Paving Cubic Yard Grouted Rubble Slope and Ditch Paving Cubic Yard Grouted Riprap Slope and Ditch Paving Cubic Yard Asphalt Slope and Ditch Paving (Asphalt) Ton Structure excavation will be measured and paid for per Section 206. Polyolefin fiber reinforcement will not be measured and paid for separately but shall be included in the work. Fog seal and asphalt required for asphalt slope and ditch paving will not be measured and paid for separately but shall be included in the work. Mortar or concrete used for grout in grouted rubble slope and ditch paving will not be measured and paid for separately but shall be included in the work. Payment for Grouted Riprap Slope and Ditch Paving will be full compensation for all work and materials required to complete the item. 508.01 508-1 SECTION 508 TIMBER STRUCTURES DESCRIPTION
508.01 This work consists of the construction of timber structures and timber portions of other
structures per these specifications and in conformity with the lines and grades shown on the plans or established. MATERIALS
508.02 Sawn lumber and timber shall conform to AASHTO M 168. Timber shall be Douglas Fir of
the coast region or Southern Yellow Pine. “Native” timber may be used when noted on the plans. “Native” timber shall be Red Cedar, Douglas Fir of the inland region, Lodgep ole Pine, Ponderosa Pine, Spruce, as listed and described in AASHTO M 168, or any other native wood specifically approved for the intended purpose. All timber shall be of the grade or shall meet the working stresses shown on the plans. Timber used in non- structural applications, whose working stresses are not shown on the plans, shall be graded to produce a working stress of 1,000 pounds per square inch on the extreme fibers when subjected to bending and 800 pounds per square inch when subjected to compression parallel to the grain. Material of equal or greater stress values may be used. All lumber shall be manufactured per Product Standard 20 -70 as published by the Department of Commerce and shall be grade- marked by a grading agency or have an accompanying certificate from a grading agency. The grading agency shall be certified by the Board of Review of the American Lumber Standards Committee.
508.03 Treated Timber. The preservative to be used shall be as specified on the plans. The
preservatives and entire treatment process shall be as described in AASHTO M 133 or by the American Wood Protection Association (AWPA) standards.
508.04 Inspection. All timber furnished shall be covered by a certificate of inspection issued
by the American Lumber Standard Committee (ALSC) or the International Accreditation Service (IAS) accredited inspection agency. Inspection approval shall be marked on each piece. Shop drawings shall be submitted per subsection 105.02 for all major structures and for other structures when specified. The Department may provide an inspector at the treating plant for material quality review and inspection of the treatment process for treated timber. The plant shall notify the Engineer sufficiently in advance of time of treating so that inspection may be arranged.
508.05 Hardware. Hardware shall include all bolts with necessary nuts and washers, timber
connectors, drift pins, dowels, nails, screws, spikes, metal pile protectors, steel anchor plates and all other metal fastenings as shown on the plans. Bolts shall conform to the re quirements of Section 509. Bolts over 12 inches long shall be threaded at least 4 inches. Drift bolts, spikes, boat spikes and other spikes shall be wrought iron or steel. Washers shall be standard cast iron ogee or malleable cast washers. Timber connectors and common nails shall be of the type and size specified on the plans. All hardware, except timber connectors and common nails, shall be galvanized per AASHTO M 232.
Source: Colorado Standard Specifications for Road and Bridge Construction, 2023 Edition. Pages 473–476 of 943.