Method of Measurement 305.06 Aggregate for subgrade modification will be measured the cubic yard or ton in accordance with Section 109-Measurem and Payment. Moisture in the aggregate will be deducted in accorda with subsection 109.01, if provided in the special provisions. When s and stone (or gravel) are designated as alternative materials for items in the bid schedule and payment is by weight, the estima quantities will be based on assumed average bulk specific gravities available alternative materials. No adjustment in contract unit pr will be made for variation in quantity due to differences in the spec gravity of the material actually used. Water will be measured by the M G. (1,000 gallons) (3.785 m3) means of calibrated tanks or distributors or by means of accurate wat meters furnished by the Contractor. Only that water which is used mixing materials or applied as ordered by the Engineer to keep t surface moist will be measured for payment. Chemical additives will be measured by the ton. If sacked chemi additives are used, the net weight as packed by the manufacturer w be used for measurement. Processing for subgrade modification will be measured by the stati or by the mile as indicated on the plans and shall include all blading ditches and shoulders, if called for on the plans; the scarifying ar pulverizing of the existing surface; all placing and mixing of materia on the road; the compacting of the materials; the finishing of th surface; and the maintenance of the completed surface if applicable. Basis of Payment 305.07 The accepted quantities of Subgrade Modification deter mined as provided above will be paid for at the contract unit price bi per ton or cubic yard for aggregate for subgrade modification, per MG (1,000 gallons) (3.785 m3) for water, per station or mile for processing and per ton for chemical additives, which price and payment will be ful compensation for the work of this section. Payment will be made under: Pay item 305(1) Aggregate for subgrade modification, 305(2) Aggregate for subgrade modification, Pay unit Cubic yard. Ton. M G. Mile. Ton. Ton. Pay item Pay unit Ton. Section 306.-RECONDITIONING ROADBED Description 306.01 This work shall consist of reconditioning the surface of an existing road, cleaning and reconditioning the ditches, including culvert inlets and outlets, and shaping the shoulders, all in reasonably close conformity with the plans and these specifications, immediately prior to the application of a prime coat or to the placing of a base or surface course. Construction Requirements 306.02 The road, including the shoulders, shall be scarified to the depth and width required, except as provided below. The scarified material shall be pulverized so that not more than 5 per cent of this material, exclusive of gravel or stone, will be retained on a 2-inch (50 mm) sieve. The pulverized material shall be moistened, shaped and compacted to the density as specified in subsection 305.04. Blading and watering of the surface, if ordered, shall be continued during the rolling operations. Existing bituminous surface shall be scarified and pulverized until all lumps are reduced to a size not greater than 11⁄2 times that of the maximum size aggregate in the existing bituminous surface. The bituminous aggregate shall then be windrowed or otherwise conserved for further use in the work, if not incorporated and compacted in the roadbed. The surface shall be satisfactorily maintained until the base or surface course has been placed. If required, additional water shall be applied to prevent checking or raveling. Where a hard and compact surface is encountered, whether or not previously bituminized or otherwise concreted, which, as determined by the Engineer, would be weakened or damaged by scarifying and blading, all depressions and breaks shall be corrected by patching and leveling to conform with the surrounding surface. The Engineer will direct the type of material to be used for patching from materials included in the contract. Any soft, unstable or other unsuitable materials in the roadbed sha be removed as directed and replaced with suitable material o stabilized by means of chemical additives shown in subsection 305.0 and included in the bid schedule, as directed by the Engineer. Th material shall be placed in loose layers of not more than 8 inches (203 mm) in depth and each layer shall be thoroughly compacted as provided above. The surface shall be finished in reasonably close conformity to the grade and cross section of the adjoining undisturbed roadbed. Method of Measurement 306.03 Reconditioning will be measured by the station or by the mile as indicated on the plans and shall include all blading of ditches and shoulders if required, the scarifying and pulverizing of the existing roadbed, the preparation, incorporation, or conservation of existing bituminous materials, the compacting of the roadbed, the finishing of the surface, and the maintenance of the completed surface if applicable. Water will be measured by the M G. (1,000 gallons) (3.785 m3) by means of calibrated tanks or distributors or by means of accurate water meters furnished by the contractor. Only that water which is used in mixing materials or ordered by the Engineer to keep the surface moist will be measured for payment. Removal and replacement of unsuitable material in the roadbed will be measured for payment under Section 203. Patching and leveling material will be measured for payment under the applicable sections. Chemical additives ordered by the Engineer and acceptably incorporated into the roadbed will be measured by the ton. Basis of Payment 306.04 The accepted quantities of reconditioning determined as provided above will be paid for at the contract unit price per station or mile for reconditioning and per M G. (1,000 gallons) (3.785 m3) for water, complete in place, which price and payment will be full compensation for the work of this section. Payment will be made under: Pay item 306(1) Reconditioning of roadbed. 306(2) Reconditioning of roadbed___ Pay unit 306(3) Water for reconditioning of roadbed---- M G. roadbed Ton. Section 307.-RESERVED Section 308.-PORTLAND CEMENT TREATED BASE COURSE Description 308.01 This work shall consist of constructing one or more courses of a mixture of aggregate and portland cement on a prepared surface in accordance with these specifications in reasonably close conformity with the lines, grades, thicknesses 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 as described below. Materials 308.02 Materials shall conform to the requirements specified in the following subsections: 308.03 Travel Plant Method. The aggregate obtained from scarifying the existing roadway or from other sources shall be pulverized until at least 80 percent of all material other than stone or gravel will pass a No. 4 (4.75 mm) sieve prior to compaction. Any material retained on a 3-inch (75 mm) sieve and other unsuitable material shall be removed. If additional material is specified, it shall be blended with the existing material. All butt joints at existing pavement or other structures shall be cleaned prior to mixing. The subgrade shall support all equipment required in the construction of the base. Soft or yielding areas shall be corrected prior to mixing. The aggregate to be treated shall be placed in a uniform windrow or spread to a uniform thickness to the width required. The specified quantity of portland cement shall be applied uniformly in a trench on top of the windrow or spread uniformly over the aggregate. Spre cement that has been lost shall be replaced, without additional comp sation, before mixing is started. Mixing shall be accomplished by means of a mixer that thoroughly blend the aggregate with the cement. The mixer shall equipped with a water metering device that will introduce the requir quantity of water during the mixing cycle. The cement-aggregate m ture shall be sufficiently blended to prevent the formation of ceme balls when water is applied. A maximum time of 2 hours shall be permitted for wet mixin lay-down, and finishing when the "Travel Plant Method" is used. Other mixing methods and equipment may be used for areas consis ing of 10,000 square yards (8361 m2) or less when approved. 308.04 Central Plant Method. The aggregate shall be propo tioned and mixed with cement and water in a central mixing plant. T plant shall be equipped with feeding and metering devices which w introduce the cement, aggretate, and water into the mixer in t quantities specified. Mixing shall continue until a uniform and intima mixture of aggregate, cement and water has been obtained. Mixed material shall be transported to the roadway in suitable veh cles and spread on a moistened subgrade or base in a uniform layer b approved equipment. Not more than 60 minutes shall elapse betwee the start of mixing and the time of starting compaction of the cemer treated mixture on the prepared subgrade. 308.05 Compaction and Finishing. After the cement-treate mixture has been spread, the mixture shall be compacted to a density not less than 95 percent of the maximum density determined in the fiel on a sample of cement-aggregate mixture obtained from the area bein processed at the time compaction begins, in accordance with AASHT T 134. In-place field density determinations will be made in accordanc with AASHTO T 191, T 205, or other approved method. The use o AASHTO T 224 to correct for oversize particles may be required. Any mixture of aggregate, cement, and water that has not been compacted shall not be left undisturbed for more than 30 minutes. The percentage of moisture in the completed mixture shall be in a range from the optimum moisture content of the mixture to ±2 percentage points, as determined by AASHTO T 134. The compaction and finishing shall be completed within 2 hours of the time water is added to the mixture. The compacted surface shall be at proper cross section, smooth, dense, and free of compaction planes, ridges or loose material. 308.06 Protection and Curing. The completed cement-treated base shall be cured with a bituminous curing seal applied as soon as possible after the completion of final rolling. The surface shall be kept moist until the seal is applied. Curing seal shall be applied at a rate between 0.10 and 0.25 gallon per square yard of surface. The exact rate will be determined by the Engineer. The curing seal will be applied in sufficient quantity to |