LARIMER COUNTY RURAL AREA ROAD STANDARDS

Appendix D – Construction StandardsSection D.2 Revisions to CDOT Standards Specifications for Road and Bridge Constructionsegregation of the materials) to thoroughly process one half of the windrowed material to auniform mixture. Place the processed mixture to grade and compact with a pneumatic tire roller,as specified in this section. Repeat this procedure for the material in the second windrow.Apply a final application of 0.10 gallon per square yard of magnesium chloride to the entirefinished surface. Allow the magnesium chloride to soak in for thirty minutes or as needed toprevent surface displacement before final rolling. Compact the entire cross section with a steeldrum roller in accordance with this section of the specifications. Do not allow traffic on thetreated surface until approved.D.2.9 Revision of Section 308 – Fly Ash Treated SubgradeREVISION OF SECTION 308FLY ASH TREATED SUBGRADESection 308 is hereby added to the Standard Specifications for this project as follows:DESCRIPTION308.01 This work shall consist of treating the subgrade, existing subbase or existing base bypulverization, adding Class “C” fly ash, mixing and compacting of the mixed material to therequired density. This work applies to natural ground or embankment and shall be constructedas specified herein and in conformity with the typical sections, lines, and grades as show on theplans or as established by the Engineer.MATERIALS AND EQUIPMENT(a)Fly Ash. Fly Ash shall meet ASTM Specification 618, Section 3.2, when sampled andtested in accordance with Sections 4, 6, and 8, unless otherwise shown on the plans.Fly ash shall be of the class “C” designation containing a minimum of 25 percent CaO.Fly ash shall be stored and handled in closed weatherproof containers until immediatelybefore distribution on the road.If stored in bins are used; they shall be completely enclosed. Materials in bags shall bestored in weatherproof buildings with adequate protection from ground dampness.Fly ash shall be furnished in trucks, each truck shall have the weight of fly ash certifiedon public scales or the Contractor shall place a set of standard platform truck scales orhopper scales at a location approved by the Engineer.(b)(c)Water. The water used in the stabilized mixture shall be clean, clear, and free ofsewage, vegetable matter, oil, acid, and alkali. Water known to be potable may be usedwithout testing. All other sources shall be tested in accordance with AASHTO T-26 andapproved by the Engineer.Equipment. The machinery, tools, and equipment necessary for proper prosecution ofthe work shall be on the project site and approved by the Engineer prior to the beginningof construction operations. All machinery, tools, and equipment used shall beLarimer County Rural Area Road Standards Page D-10October 22, 2007