302 – LIME TREATED SUBGRADE 300-6 g. Compaction of the Mixture. When the material is mixed in-place, compact the material after completing the required final mixing. When the material is mixed off-site, excavate and haul th e material to the project site. Place the material on the prepared and trimmed surface, and compact the material. Compact the mixture to Type B compaction, MR-3-3 moisture control, SECTION 205 . Blade the mixture to eliminate surface irregularities during the compaction operations. Maintain th e moisture content to a minimum of 3% above optimum of the proctor density of the lime treated soil.
h.Finishing and Curing the Lime Treated Subgrade. After the mixture is compacted, use automatic grade controlled equipment to trim the lime treated subgrade to the specified lines and grades. In irregular areas, trim the lime treated subgrade by wetting, blading and rolling. Compact the trimmed surface with a smooth-wheel or a pneumatic-tire roller. After the compacted mixture is finished, cure the lime treated subgrade for 7 days, by keeping the finished surface moist with water. Do not allow vehicles or equipm ent (other than watering equi pment) on the finished lime treated subgrade during the curing period. At the Contractor’s option, apply an asphalt prime co at instead of keeping the finished surface moist with water. If asphalt prime coat is used, apply SS-1, CSS-1 or MC-250 at the rate of 0.22 gallons per square yard to achieve a minimum of 0.13 gallons per square yard residue. The use of a liquid membrane forming compound is also an acceptable curing medium. Mu ltiple light applications may be necessa ry to obtain the specified rate of application without run-off. When a base course or subbase is to be constructed upon the lime treated subgrade, the Engineer may reduce the curing period to when the lime treated subgrade gains sufficient strength to support the construction and hauling equipment. Repair any damage to the lime treated subgrade due to construction of the base course or subbase.
i.Seasonal Limitations. Do not perform lime treatment operations if the ambient air temperature is below 40°F, or the soil is frozen. (1) Projects with Rigid Pavement. Cover the finished lime treated subgrade with base or pavement before it is subjected to freezing. If the lime treated subgrade is not covered by base or pa vement and is subjected to freezing, re-compact the lime treated subgrade before placing any pavement . The Engineer will determine the extent of the re-compaction.
2.Projects with Flexible Pavement. Cover the finish ed lime treated subgrade with the specified lift of HMA or aggregate base before it is subjected to freezing. If lime treated subgrade is no t covered with a lift of HMA or aggregate base and is subjected to freezing, add additio nal lime and re-compact the lime treated subgrade before placing any pavement. The Engineer will determine (by laboratory or field tests) the additional quantity of lime to add, if any, and the extent of the re-compaction. 302.4 MEASUREMENT AND PAYMENT The Engineer will measure lime by the ton. If bagged lime is used, the Engineer will use the net weight marked on the bag by the manufacturer for the measurement. If certified railroad car or certified truck quantities are used, the Engineer will use the net weight of the lime for the measurement. Using the relationship for Pure Quicklim e (CaO) x 1.32 = Hydrated Lime (Ca(OH) 2), determine the basis of pay for jobsite slaked hydrated lime (A+B) according to subsection 302.3b. using the certified lime purity for each load. Calculate the pay quantity for carbide lime as follows: Pay Quantity = (Weight of material delivered) (% solids) The percent moisture will not be credited toward water for pay. The Engineer will measure the manipulation of the lime treated subgrade by the square yard. Material placed beyond the neat lines indicated in the Contract Documents is not measured for payment without approval by the Engineer. The Engineer will measure water used for lime treated subgrade by the M Gallon using calibrated tanks or water meters. The Engineer will measure water used for subgrade preparation, mixing subgrade and lime, compacting and curing the lime treated subgrade. The Engi neer will not measure water used for slaking the lime, 302 – LIME TREATED SUBGRADE 300-7 dust control, water wasted through the Contractor’s negligence or water in excess of the quantity required for mixing and compacting the lime treated subgrade. If the Contractor opts to use asph alt prime coat or liquid membrane forming compound to cure the lime treated subgrade, the Engineer will not measure the asphalt prime coat for payment or liquid membrane forming compound. The Engineer will not measure for payment, the lime, manipulation or water used for adding additional lime or re-compaction if: The off-site borrow area mixture is not used with 14 days of the preliminary mixing. The lime treated subgrade is not covered with paveme nt before it is exposed to freezing temperatures. Payment for "Lime" and "Manipulation (Lime Treated Subgrade)" at the contract unit prices and "Water (Lime Treated Subgrade) (Set Price)" at the contract set unit price is full compen sation for the specified work. 302 – LIME TREATED SUBGRADE 300-8 TABLE 302-1: STRENGTH OF HYDRATED LIME SLURRY Lb. per gal. of suspension Lb. Ca (OH) 2 per gallon, suspension 8.41 .135 8.50 .272 8.58 .412 8.66 .546 8.75 .691 8.83 .830 8.91 .962 8.99 1.106 9.08 1.244 9.16 1.392 9.25 1.517 9.33 1.679 9.41 1.816 9.50 1.948 9.58 2.09 9.66 2.23 9.75 2.38 9.85 2.52 9.91 2.68
10.00 2.80
10.08 2.94
10.16 3.09
10.24 3.24
10.33 3.39
10.41 3.52
10.49 3.71
10.58 3.86
10.66 4.00
10.74 4.15
10.83 4.29
10.91 4.45
11.00 4.60
11.08 4.73
11.16 4.90
11.25 5.04
11.33 5.18
11.41 5.32
11.50 5.49
11.58 5.62
11.66 5.78
11.75 5.95
11.83 6.09
11.91 6.22
12.00 6.37
12.08 6.51
303 – CEMENT OR FLY ASH TREATED SUBGRADE 300-9 SECTION 303 CEMENT OR FLY ASH TREATED SUBGRADE 303.1 DESCRIPTION Mix subgrade soil, cement or fly ash and water to construct a uniform treated subgrade as shown in the Contract Documents. B I D I T E M S U N I T S C e m e n t T o n F l y A s h T o n Manipulation for Treated Subgrade (*) Square Yard Water (Treated Subgrade) (Set Price) M Gallon * Cement or Fly Ash 303.2 MATERIALS Provide materials that comply w ith the applicable requirements. Emulsified Asphalt (S S-1 or CSS-1) ..................................................................... DIVISION 1200 Medium Cure Cutback Asphalt (MC- 250) ............................................................ DIVISION 1200 Concrete Admixtures & Curing Mate rials ............................................................. DIVISION 1400 Portland Cement & Blende d Hydraulic Cement ................................................... DIVISION 2000 Fly As h .................................................................................................................. DIVISION 2000 Water for Treated Subgrade .................................................................................. DIVISION 2400 303.3 CONSTRUCTION REQUIREMENTS
a.Subgrade Preparation. Prepare the subgrade to the lines and grad es shown in the Contract Documents. Scarify the prepared subgrade to the depth of treatment designated in the Contract Document prior to applying the cement or fly-ash. Perform the scarification with positive depth control equipment. Do not use a plow or disc for the scarification. Based on performance, the Engineer may approv e the use of an automatic grade control motor grader scarifier. Bring the sc arified subgrade to within the specified moisture content of the previous moisture range before adding cement or fly ash.
b.Application. On projects having more than 20,000 square yards of manipulation, apply cement or fly ash using a controlled application system. This system may be pressurized or mechanical in nature, utilizing vane or augers feeding cement or fly ash through a funnel or hood at a controlled rate. On projects having less than 20,000 square yards of manipulation, and in irregular areas, submit a plan to the Engineer for approval that includes equipment and procedures that address subgrade preparation and application process to spread the cement or fly ash at the specified rate. On projects having more than 20,000 square yards of manipulation, and consisting of multi-phased construction, contact the District Office for approval to waive the use of the controlled application system. Consideration will be based on the Cont ractors proposed alternate method of applying the cement or fly ash, the square yards of manipulation in each phase, and th e size of individual areas within each phase. Do not apply the cement or fly ash when conditions are such that the material is lost due to the wind. Do not use cement or fly ash that was not properly handled and not stored in weatherproof containers. The Engineer will check the application rate of cement or fly ash by having the Contractor blade a flat area in the path of the cement or fly ash application, place a planar surface with a minimum surface area of 1 square foot (e.g. a straight-sided pan) and of sufficient height to co ntain the admixture on the prep ared area and allow the train to pass over the surface. Weigh the test surface before and after the cement or fly ash a pplication and calculate the application rate. Other methods to check the application rate may be used. 303 – CEMENT OR FLY ASH TREATED SUBGRADE 300-10 c. Mixing. Mix the scarified subgrade and cement or fly ash. Continue mixing and adding water until a homogeneous, friable mixture that complies with TABLE 303-1 is obtained. Use equipment with a recycling or mixing drum, and with an automatic water proportioning system to pulverize the subgrade to the specified depth. Do not perform treated subgrade operations when the ambient air temperature is below 40°F, or the soil is frozen. TABLE 303-1: PERCENT RETAIN ED - SQUARE MESH SIEVES* 1½-inch ½-inch 0 50 maximum *The Engineer will determine the percent retained on the specified sieves according to KT-42. Complete the mixing within 30 minutes of adding th e cement or fly ash to the pulverized subgrade. The uniform moisture content of the mixture immediately before being compacted shall be ±3 percentage points of the optimum moisture content. If the moisture content of the mixture exceeds the specified moisture content, add additional cement or fly ash to lower the moistu re content. Spray the mixture with water, as necessary, to maintain the specified moisture content during the compaction operations.
d.Compaction. For the initial compaction of the mixture, use a vibratory roller having a minimum operating weight of 12 tons, with a minimum centrifugal force of 24 tons. Use a rubber-tired or smooth-wheeled roller to complete the compaction of the surface. When the thickness is greater than 6 inches, compact multiple lifts of equal thickness with a maximum lift thickness of 6 inches . Compact the treated su bgrade to a minimum of 95% of the combined materials dry density. Complete the compaction operations within 2 hours of incorporating the cement or fly ash into the subgrade. If any of these requir ements are not satisfied, reprocess, recompact and refinish the deficient areas.
e.Trimming. After compaction of the treated subgrade, trim and recompact the treated subgrade to the specified lines and grades. On projects having more than 20,000 square yards of manipulation, use automatic grade controlled equipment to trim the subgrade. In irregular areas, trim the subgrade by wetting, blading and rolling.
1.Option 1. After compaction is complete, trim and recompact the subgrade within 2 ½ hours of the time the water and cementing agent is added to the subgrade. Recompact the trimmed surfa ce of the treated subgrade with a smooth-wheel or a pneumatic-tire roller. Lightly scarify and blade the surf ace to eliminate equipment imprints while performing final rolling.
2.Option 2. After compaction is complete, trim the tr eated subgrade after 2 ½ hours of the time the water and cementing agent is added to the su bgrade. After curing according to subsection 303.3f. , recompact the trimmed surface of the treated subgrade with a smooth-wheel or a pneuma tic-tire roller. Remove loose trimmed material from any low spots and fill with the next course of material at the Contractor’s expense.
f.Curing. Protect the finished subgrade against drying for 7 days after completion (Option 1-after compaction, Option 2-after trimming), or until the subgrade is covered with a base or surfacing if covered before 7 days. Protect the finished subgrade from drying by spraying with water to maintain a continuous moist condition. The Contractor may apply an asphalt prime coat instead of keeping the finished surface moist with water during the curing period. If this option is chosen, apply SS-1, CSS-1 or MC-250 at the rate of 0.22 gallons per square yard to achieve a minimum of 0.13 gallons per s quare yard residue. Multiple light app lications may be necessary to obtain the specified rate of application without runoff.
g.Construction Traffic. Avoid placing construction loads or operating equipment until the treated subgrade has cured and can withstand the loads without damaging the subgrade. If the subgrade deforms under the construction loads and cannot return back to its original condition, or if it deflects more than 1 inch, allow the subgrade additional curing time before operating equipment on the subgrade. Repair any damaged subgrade.
h.Succeeding Course. Cover the finished treated subgrade w ith the specified lift of HMA or aggregate base before it is subjected to freezing. If the finished treated subgrade is not covered with a lift of HMA or aggregate base and is subjected to freezing, the Engineer will determine when the subgrade needs to be reworked. KDOT will not pay for the replacement a nd refinishing of the treated subgrade if the material loses the required stability, density or finish before the next course is placed. 303 – CEMENT OR FLY ASH TREATED SUBGRADE 300-11 303.4 MEASUREMENT AND PAYMENT The Engineer will measure cement or fly ash used in the mixture by the ton. The Engineer will not measure additional cement or fly ash added to the mixture to reduce the moisture content. The Engineer will measure the manipulation for treated subgrade by the square yard. The Engineer will measure water used for cement tr eated subgrade by the M Gallon using calibrated tanks or water meters. The Engineer will measure water used for preparation of the subgrade, mixing subgrade and cement or fly ash, and the 7-day protection from drying period. The Engineer will not measure water used for dust control, water wasted through the Contractor’s negligence or water in excess of the quantity required for mixing and compacting the cement subgrade. If the Contractor opts to use asphalt material to cure the treated subgrade, the Engineer will not measure the asphalt material for payment. Payment for "Cement", "Fly Ash" and "Manipulation fo r Treated Subgrade" at the contract unit prices and "Water (Treated Subgrade) (S et Price)" at the contract set unit price is full compensation for the specified work. 304 – CRUSHED STONE SUBGRADE 300-12 SECTION 304 CRUSHED STONE SUBGRADE 304.1 DESCRIPTION Construct a uniform crushed stone subgrade as backfill in cut sections or as topping of fill sections as shown in the Contract Documents. B I D I T E M S U N I T S Crushed Stone Subgrade (*) Square Yard Water (Crushed Stone Subgrade) (Set Price) M Gallon *Thickness 304.2 MATERIALS Provide materials that comply w ith the applicable requirements. Aggregates fo r Backf ill ......................................................................................... DIVISION 1100 Water for Crushed St one Subgrade ....................................................................... DIVISION 2400 304.3 CONSTRUCTION REQUIREMENTS Prepare the cut or fill section for the crushed st one subgrade by scarifying, watering, blading and compacting to the specified lines and grades. Do not place crushed stone subgrade on frozen subgrade. The Engineer will obtain a sample of the crushed stone for backfill from materials stockpiled at the project site, and submit to MRC where the relative density will be determined using KT-69. Allow 48 hours for testing by the MRC. Uniformly mix the crushed stone with a sufficient qu antity of water to provide satisfactory compaction. The mixing methods are: Central Plant Method. Use a stationary mechanical mixing plant to mix the water and aggregate. Road Mix Method. After the aggr egate is placed in a uniform windr ow, use a motor grader, or other equipment approved by the Engineer, to mix the water and the aggregate. Spread and compact the crushed stone subgrade as specifi ed in the Contract Documents. If the thickness is greater than 6 inches, spread and compact the crushed st one subgrade in multiple lifts of equal thickness with a maximum lift thickness of 6 inches. Compact the crushed stone subgrade to a uniform density, a minimum of 70% of the relative density. The Engineer will verify th e relative density using a nuclear gauge (KT-41). If during production, the gradation changes ±10% from the single point designation on any single sieve, cease spreading and compaction operations. The Engineer will obtain a new sample for relative density, submit sample to the MRC and a new relative density value will be established. 304.4 MEASUREMENT AND PAYMENT The Engineer will measure crushed st one subgrade by the square yard. The Engineer will measure water used for crushed st one subgrade by the M Gallon using calibrated tanks or water meters. The Engineer will measure water us ed for subgrade preparation, mixing and compacting the crushed stone subgrade. The Engineer will not measure water used for dust control, water wasted through the Contractor’s negligence or water in excess of the quantity required for mixing and compacting the crushed stone subgrade. Payment for "Crushed Stone Subgrade" at the contr act unit price and "Water (Crushed Stone Subgrade) (Set Price)" at the contract set unit price is full compensation for the specified work. 305 – AGGREGATE BASE AN D AGGREGATE SHOULDERS 300-13 SECTION 305 AGGREGATE BASE AND AGGREGATE SHOULDERS 305.1 DESCRIPTION Construct aggregate base and aggregate shoulders on prepared subgrade as shown in the Contract Documents. B I D I T E M S U N I T S Aggregate Base (*)(**) Square Yard Aggregate Shoulder (*)( * * ) S q u a r e Y a r d C a l c i u m C h l o r i d e T o n Water (Aggregate Base) (Set Price) M Gallon Water (Aggregate Shoulders) (Set Price) M Gallon *Type of Aggregate **Thickness 305.2 MATERIALS Provide materials that comply w ith the applicable requirements. Aggregate for Aggr egate Base .............................................................................. DIVISION 1100 Aggregate for Shoulder ......................................................................................... DIVISION 1100 Calcium Chloride .................................................................................................. DIVISION 1700 Water for Aggregate Base an d Aggregate Shoulder .............................................. DIVISION 2400 305.3 CONSTRUCTION REQUIREMENTS
a.Subgrade Preparation. Unless other subgrade preparation is included in the Contract Documents, water, scarify, blade and compact the roadway and shoulde r subgrade to obtain the lines and grades shown in the Contract Documents. Remove all vegetation before sh aping and rolling. Remove and dispose of any excess material. If additional embankment material is needed, obtain the material from locations shown in the Contract Documents or as directed by the Engineer. Excavate the subgrade as shown in the Contract Documents. If existing pavements or bridges are encountered, excavate the subgrade at all control points to a depth that will allow placement of the required thickness, flush with the existing surface. Use a transition (from normal to speci al section) of sufficient length to prevent an abrupt or noticeable change in grade. Remove and dispose of the excavated subgrade. Compact the excavated areas to a depth of 6 inches, according to th e Contract Documents. When subgrade compaction is not specified in the Contract Documents, compact the excavated areas to a depth of 6 inches, according to Type B, MR- 90, SECTION 205 .
b.Mixing. The mixing methods are: Central Plant Method. Use a stationary mechanical mixing plant to uniformly mix the water and aggregate. Road Mix Method. After the aggr egate is placed in a uniform windr ow, use a motor grader, or other equipment approved by the Engineer, to uniformly mix the water and the aggregate. Mix the aggregate with sufficient water to allow compaction of the mixture to the specified density. If the aggregate is predominantly limestone, use the central plant. Use a central plant or road mix method to mix types of granular aggregate other than limestone, or to mix any type of aggregate if the original contract quantity is less than 15,000 square yards. When shown in the Contract Documents, mix calcium ch loride with the aggregate at the specified rate. Add the calcium chloride (in solution, flakes, pellets or granular) at the same time the water is mixed with the aggregate. 305 – AGGREGATE BASE AN D AGGREGATE SHOULDERS 300-14 c. Placing, Compacting and Finishing. Immediately after mixing the aggregate and water, use an aggregate spreader to place the mixture full-lane or full-shoulder width. Do not place the mixed material on the prepared subgrade when conditions are such that the haul ing and placing will damage the prepared subgrade. Do not dump or mix the aggregate on any paved surface. The maximum compacted thickness of any layer of aggreg ate base or shoulder is 6 inches. If the thickness is greater than 6 inches, spread and compact the aggregat e base in multiple lifts of equal thickness with a maximum lift thickness of 6 inches. The maximum compacted thic kness of any layer may be increased to 8 inches when vibrating compaction equipment or other compaction equipment is approved by the Engineer. On aggregate course projects without shoulders, construct all lifts, regardless of th ickness, with an edge slope of 1:1 or flatter. If the aggregate base or shoulder is constructed in more than 1 la yer, allow sufficient time for the initial layer to cure to prevent any rutting or surface di stortion from equipment being used to place the succeeding layers. Spread and compact the aggregate ba se or shoulders as specified in th e Contract Documents. Compact the aggregate base to a minimum uniform density of 95% of the standard density. Comp act the aggregate shoulders until no further consolidation is gained by additional blading and rolling. The Engineer will visually verify compaction of the a ggregate shoulders. After compacting the aggregate base, trim the surface to the specified lines and grades. On projects having more than 20,000 square yards of aggregate base, use automatic grade controlled equipment to trim the compacted aggregate base. In irregular areas, trim the aggregate ba se by wetting, blading and rolling. Compact the trimmed surface of the aggregate base with a sm ooth-wheel or a pneumatic-tire roller. When necessary, lightly scarify and blade the surface to eliminate equipment imprints while performing final rolling.
d.Curing and Maintena nce of Aggregate Base. Cure the compacted layer to develop sufficient stability to resist wheel truck rutting before vehicular hauling or h eavy equipment is permitted on the base. When Contract Documents call for a PGAB or cutback asphalt prime coat on the aggregate base, cure the compacted layer to maximum moisture content of 60% of optimum moisture content for AB-1, AB-2, & AB-4 and 70% for AB-3, prior to the construction of the Asphalt Prime Coat. The Engineer will perform testing to determine when the cure of the aggregate base is complete. The Engineer may require th at the surface of the aggregate base be kept moist during the curing period to prevent loss of surface material. Do not apply surfacing until the aggregate base is cured. Maintain the base until the surfacing is applied.
e.Shoulders, Entrances and Side Roads. When shoulder construction is not included in the Contract Documents, re-construct, compact and sh ape the existing shoulder from the top of the completed aggregate base to the shoulder line. Shape the shoulders to provide a uniform shoulder line. Raise the grade of entrances and side roads to meet the edge of the completed aggregate base. Construct, compact and shape the entrances and side roads full widt h with shoulders and shoulder radii adjacent to the shoulders of the roadway. Obtain additional embankment material for shoulders, entrances and side roads from adjacent slopes and ditches. Dispose of excess material from shoulders, entrances and side roads on adjacent backslopes. 305.4 MEASUREMENT AND PAYMENT The Engineer will measure aggregate base an d aggregate shoulder by the square yard. The Engineer will measure the water used in the mixture and used on the finished surface during the curing period by the M Gallon using calibrated tanks or distributors . The Engineer will not measure water in the mixture in excess of 5% above the optimum moisture. The Engineer will not measure water used for subgrade preparation or construction of earthen shoulders, entr ances and side roads. The Engineer will not measure water used for dust control or water wasted through the Contractor’s negligence. The Engineer will measure Grade 2 calcium chloride (c oncentrated calcium chloride or equivalent) used in the mixture by the ton. If Grade 1 calcium chloride (regular) is used, 1.2 tons of Grade 1 is the equivalent of 1 ton of Grade 2. The Engineer will not measure the wedges at the pavement edge. Payment for "Aggregate Base", "Aggregate Shoulders" and "Calcium Chloride" at the contract unit prices and "Water (Aggregate Base) (Set Price)" and "Water (Aggregate Shoulders) (Set Price)" at the contract set unit prices is full compensation for the specified work.
Source: Kansas Standard Specifications for State Road and Bridge Construction, 2015 Edition. Pages 152–160 of 978.