311Lime-Fly Ash Treated Courses

311.01 Description . This work consists of constructing one or more courses of a

mixture of soil, soil aggregate or aggregate, fly ash, lime, and water in accordance with these specifications and in reasonably close conformity with the lines, grades, thickness and typical cross sections shown on the plans or established by the Engineer. Unless otherwise provided, the Contractor may use either the travel plant or central plant method.

311.02 Materials . Soil, soil aggregate or aggregate, when Contractor furnished, shall

conform to the requirements set forth on the plans or in the contract. Other materials shall conform to the requirements of Division 700 as specified in the following subsections: Cut-back Asphalt 702.06 Emulsified Asphalt 702.07 Aggregate 703.20 Water 714.01 Lime 714.03 Fly Ash 714.05

311.02.1 Soil-Lime-Fly Ash Design . Quantities and percentages of lime and fly ash

shown on the plans are preliminary. The act ual application rate will be established from tests made prior to beginning treatment. The design of soil-lime-fly ash courses shall be performed by the Central Laboratory. At least 45 days prior to the proposed use of a lime-fly ash course, the Contractor shall make available materials conforming to the specifications and proposed for use in the mixture for sampling and testing by the Department as the Engineer may consider necessary for the establishment of a mix design. The approved proportions of material will govern during the progress of the work, and changes in source or character of any materi al shall not be made without approval. Approval will be based on verification of a mix design.

311.02.2 Curing Seals. Curing seal shall be Emulsifi ed Asphalt, Grade EA-1, EPR-1,

AE-P, CSS-1, SS-1, CMS-2h, or MS-2h meeting the applicable requirements of Section 702.

311.03 Construction Requirements .

311.03.1 General . Fly ash shall be spread at the sp ecified rate and lightly disked or

mixed into the soil or soil aggregate prior to spreading the lime. Prior to the application of fly ash, a light wi ndrow shall be bladed along the edges of the area to be treated, or the surface on which the fl y ash is to be applied shall be scarified to retain the spread fly ash. The depth of scar ification shall be carefully controlled so that the surface of the roadbed below the scarif ied material will remain undisturbed and conform to the established cross section.

311.03.2 Equipment . Equipment necessary for the proper prosecution of the work shall

meet the applicable requirem ents of Subsection 308.03.2.

311.03.3 Preparation of Grade . Before treatment, the roadbed shall be prepared in

accordance with the requirem ents of Section 321.

311.03.4 Application .

311.03.4 1--Fly Ash . Fly ash shall be applied as set out in Subsection 308.03.7, except

that weather limitations shall be in accordance with Subsection 311.03.5.

311.03.4 2--Lime . The rate of application of lime shall be as specified.

Application of lime shall be accomplished by either an approved "dry application" or "slurry application" method. The following guide lines will govern th e acceptability of the method to be used: Dry Application . Hydrated lime applied by this method shall be spread uniformly and shall be sprinkled with sufficient water to prevent loss of lime by wind. Spreading of hydrated lime when wind and weather conditions are unfavorable will not be permitted nor will spr eading of lime by motor patr ol be acceptable. The use of quick lime in the "dry applica tion" method will not be permitted. Slurry Application. Lime applied by this method shall be mixed with water in approved agitation equipment and applied to the roadbed as a thin water suspension or slurry. The distributing equipment shall be equipped to provide continuous agitation of the slurry until applied on the roadbed. The proportion of lime shall be such that the "Dry Solids Content" shall be at least 30 percent by weight. The distribution of lime at the rate specified shall be attained by one or more passes over a measured section until the specified percen tage of lime has been spread. After each successive pass the material shall be inco rporated into the soil with the mixing equipment. 311.03.5--Weather Limitations . Lime-fly ash treatment shall not be performed when either the soil or soil aggregates or the surf ace on which a lime-fly ash treated material is to be laid is wet or frozen or when it is rain ing or snowing. Processing operations for the lime-fly ash course shall not begin until the surface temperature is at least 40°F and rising. Construction of the soil/soil aggregate-lime-fly ash stabilized course will not be permitted between November 30 and March 1.

311.03.6 Fly Ash-Lime and Water Mixing Phase . The lime and water shall be

incorporated uniformly into the soil course of fly ash and aggregate. The mixing and water application shall be continued until a homogeneous mixture of which 100 percent of the material by dry weight, exclusive of gravel and stone, will pass a two-inch sieve and 60 percent will pass a No. 4 sieve. At the completion of moist mixing and during the compaction operations, the percentage of moistu re shall be that necessary to obtain the required density. No mellowing period will be required or permitted, and compaction shall begin immediately. The mixing, water application, and final compaction shall be completed during the same work day.

311.03.7 Shaping, Compacting, and Finishing.

311.03.7 1--General . The mixed material shall be sh aped as required immediately after

mixing, or delivery to the roadbed in the case of central plant mixed material. Initial compaction shall begin immediately, and machining and compacting shall continue until the entire depth and width of the course is compacted to the required density within two hours of the time of beginning mixing. Compaction shall be by equipment and methods that do not result in lamination. Areas inaccessible to rollers shall be compacted to the required density by other approved methods. The addition of thin layers of treated material in order to conform to cross sectional or grade requirements will not be permitted. Compaction by vibration shall not be performed after the lime fly-ash has taken its initial set. Vibratory compaction of a section shall be completed within one hour. During compaction, a spike-tooth harrow or other suitable equipment shall be used as required to prevent lamination. The surface shall then be reshaped to the requi red lines, grades, and cr oss section, and if necessary shall be lightly scarified to remove imprints left by the compacting or shaping equipment. The surface shall then be sprink led as necessary and thoroughly rolled with a pneumatic roller, and if the mixture contains plus No. 4 aggregate, at least one complete coverage of the section shall be made with a steel-wheel tandem roller. Surface compaction and finishing for the entire section shall be performed in a manner that will produce a smooth, closely knit su rface, free from laminations, construction cracks, ridges, or loose materi al, and conforming to the crown, grade, and lines stipulated within four hours after the beginning of mixing. Upon completion of compaction, testi ng will be performed in accordance with Subsections 700.03 and 700.04.

311.03.7 2--Density . Determination of acceptance of compaction of treated courses for

required density will be performed on a lot to lo t basis. Each lot will be each 2,500 linear feet per layer placed. At the discretion of the Engineer, a residual portion of a lot completed during a day's operation may be considered a separate lot or may be included in the previous or subsequent lot, except that any day's operation of less than one full lot will be considered a lot. The lot will be divided into five approximately equal sublots with one density test taken at random in each sublot. The average of the five (5) density tests shall equal or exceed 98.0 percent with no single density test below 94.0 percent. Sublots with a density below 94.0 percent shall be corrected at no additional cost to the State and retested for acceptance. For treated materials other than for design soils and bases, the required density will be set out elsewhere in the contract.

311.03.7 3--Width, Thickness, and Surface Requirements . For the purpose of

determining reasonable conformity with the de signated width of a treated course, it shall be understood that the width of a treated course shall not vary from the designated edge lines by more than plus or minus one inch. For the purpose of determining reasonable conformance with the designated thickness of a treated course, it shall be understood that the depth of the treated course shall not vary from designated thickness by more than minus one-half (1/2) inch or plus one (1) inch. The finished surface of a treat ed course shall conform to the requirements shown on the plans, within the tolerances allowable under Section 321.

311.03.8 Protection and Curing. Each completed course shall be covered with a

bituminous curing seal as soon as possible but no later than 24 hours after completion. The surface shall be sealed w ith one of the specified bituminous materials applied by a pressure distributor at the rate of 0.10 to 0.25 gallon per square yard or as directed by the Engineer. The bituminous material shall be heated or otherwise prepared to ensure uniform distribution. Should the Contractor fa il to seal the lime-fly ash course within the time specified, the Engineer will suspend all other work and withhold payment of the current estimate(s) until all damages resulting therefrom is corrected and the lime-fly ash course is sealed. A subsequent course shall not be placed on the sealed lime-fly ash course for at least seven (7) calendar days. During this 7-day period, the lime-fly ash course shall not be subjected to any type of traffic and equipment. The Contractor shall maintain the lime-fly ash course and the curing seal in a satisfactory condition until covered by a subsequent course. Protection shall include immediate repairs of any surface irregularities or other def ects that may occur or develop. It shall be the Contractor's responsibility to control traffic and equipment loads to avoid damage and to guard against freezing of th e lime-fly ash treated material. All damage resulting from the Contractor's failure to protect and cure the lime-fly ash course as specified herein or from freezing th at may occur prior to being covered with the next course shall be corrected at no additional cost to the State. The Contractor shall submit, for approval of the Engineer, a method of correction that will restore the strength of the damaged material to that originally specified.

311.04 Method of Measurement . Lime and fly ash will be measured by the ton in

accordance with Section 109. If bagged lime is used, the net weight as packaged by the manufacturer will be used for measurement. The basis of pay for jobsite slaked lime slurry shall be the "calculated method" as provided for jobsite slaked lime slurry in Subsection 307.04. Aggregate will be measured by the ton or cubic yard (LVM). When measurement is by weight, the weight of moisture, surf ace and hygroscopic, will be deducted. Processing will be measured by the square yard and shall include preparation of the roadbed, scarifying, pulverizing, drying of the material, mixing of the various materials, compaction of the mixture, finishing, protection and curing, and maintenance of the completed course. Bituminous curing seal will be measured by the gallon as prescribed in Subsection

109.01 Unless otherwise specified, distributor tank measurements will be used. The

volume of material over five percent above the allowed range for each shot will be deducted from measured quantities, except that 15 percent will be allowed for irregular areas where hand spraying is necessary. The volume of all bituminous material lost, wasted, damaged, or rejected, or applied outside of designated areas, or in excess of the Engineer's directions and tolerances allowed, or contrary to the specifications, will be deducted from measured quantities. Water will not be measured for separate payment.

311.05 Basis of Payment . The accepted quantities of lime and fly ash treated material

will be paid for at the contract price per ton for lime and fly ash, per ton or cubic yard (LVM) for aggregate, and per square yard for processing lime and fly ash treated material complete in place. The prices thus paid shall be full compensation for completing the work. Bituminous curing seal, measured as prescribed above, will be paid for at the contract unit price per gallon, which price shall be full compensation for furnishing, applying and reapplying if needed, protecting, maintaining; and all tools, equipment, labor and incidentals necessary to complete the work. Payment will be made under: 311-A: ___” Processing Lime and Fly Ash Treated Course - per square yard 311-B: Lime - per ton 311-C: Fly Ash, Class____ - per ton 311-D: Aggregate - per cubic yard or ton 311-S: Bituminous Curing Seal - per gallon SECTION 320 - SHOULDERS

320.01 Description . This work consists of constructing the shoulder portion of courses

specified to be constructed; the shaping, comp acting, finishing, and surfacing, if required, of the shoulder portion of the work in reasonably close conformity with the required lines, grades, and cross sections; and the construction and establishment of erosion