LARIMER COUNTY RURAL AREA ROAD STANDARDS

Appendix D – Construction StandardsSection D.2 Revisions to CDOT Standards Specifications for Road and Bridge Constructionloosened stabilized material from the section. Recompaction of the loose material should not beattempted. The surface shall then be thoroughly compacted with the pneumatic roller, addingsmall increments of moisture as needed during rolling. If plus No. 4 aggregate is present in themixture, one complete coverage of the section with the fat wheel roller shall be madeimmediately after the “clipping” operation. When directed by the Engineer, surface finishingmethods may be varied from this procedure provided a dense, uniform surface, free of surfacecompaction planes, is produced. The moisture content of the surface material must bemaintained within the specified range during all finishing operations. Surface compaction andfinishing shall proceed in such a manner as to produce, in not more than two hours, a smooth,closely knit surface, free of cracks, ridges or loose material conforming to the crown, grade, andline shown on the plans.After the fly ash treated course has been finished as specified herein, the surface shall beprotected against rapid drying by either of the following curing methods for a period of not lessthan three days or until the surface or subsequent courses are placed:(a)(b)(c)Maintain in a thorough and continuously moist condition by sprinkling.Apply a two-inch layer of earth on the completed course and maintain in a moistconditionApply an asphalt membrane to the treated course, immediately after same is completed,the quantity and type of asphalt approved for use by the Engineer shall be sufficient tocompletely cover and seal the total surface of the base between crown lines and allvoids. If the Contractor elects to use this method, it shall be the responsibility of theContractor to protect the asphalt membrane from being picked up by traffic by eithersanding or dusting the surface of same. The asphalt membrane may remain in placewhen the proposed surface or other base courses are placed. Asphaltic emulsions arenot acceptable for the asphaltic membrane.After the fly ash treated course has been finished a specified, the treated area shall remain freeof all construction & vehicular traffic for a minimum of 24 hours.D.2.10 Revision of Section 401 – Plant Mix PavementsREVISION OF SECTION 401PLANT MIX PAVEMENTS – GENERAL(NON-VOIDS ACCEPTANCE)Delete subsection 401.02(a) and replace with the following:Prior to beginning paving each calendar year, the contractor shall submit to the County forreview and approval, a mix design for each mix type he proposes placing in Larimer Countyright of way. The County may also require mix designs from the Contractor during the yearbecause of changes in the physical properties or source of the aggregates, or physicalproperties or source of the binder. Mix designs shall be developed using the SuperPavemethod of designing paving mixtures.Larimer County Rural Area Road Standards Page D-13October 22, 2007