302.03 Construction Requirements.
b.Price Adjustments . When layers failing to meet the gradation band requirements are permitted to remain in place as specified in Subarticle 301.05(c), unit price adjustments will be m ade as specified therein.
c.Payment will be made under Item No.: 301-A * t Course, Type tt , ** , ttt Mixed, inches {mm} Compacted Thickness - per square yard {square meter} 301-B * t Course, Type tt , ** , ttt Mixed, - per cubic yard {cubic meter} 301-C Cement - per ton {metric ton} 301-D Lime - per ton {metric ton} 301-E * t Course, Type tt , ** , ttt Mixed, - per ton {metric ton} * Base Classification (Selected Materials, etc., Granular Soil, Soil Aggregate, Processed Reef Shell, Crushed Aggregate) t Base or Subbase tt Type ** Insert "with cement or lime additive," if required ttt Road, Yard, or Plant FULL DEPTH RECLAMATION WITH PORTLAND CEMENT
302.01 Description.
Full Depth Reclamation with Portland cement shall consist of pulverizing and mixing the in place existing materials as shown in the plans with Portland cement and water to produce a unif orm mixture and then compacting the mixture to serve as a base course for pavement.
302.02 Materials.
a.Cement. Cement shall meet the requirements given in Section 815 "Cement" for Type I or Type II Portland Cement.
b.Water. Water shall meet the requi rements given in Section 807.
302.03 Construction Requirements.
a.Offset Reference for the Establishment of the Roadway Alignment. The Contractor shall establish offset reference points before beginning of construction so that the original alignment of the roadway (centerlines, edges of pavement, etc.) will be restored during construction.
b.Job Mix Design. A "Job Mix Design" is a listing of all components of the mixture required for the full depth reclamation. If a Job Mix Design is shown on the plan s the Contractor shall use that mix design for the full depth reclamation work. If a Job Mix Design is not shown on the plans the Contractor shall determine the composition of the Job Mix Design and submit it to the Engineer for review. The Engineer will forward the proposed Job Mix Design to the Materials and Tests Engineer for approval. Job Mix Designs shown on the plans and submitted Job Mix Designs approved by the Materials and Tests Engineer shall not be changed without written approval of the Engineer . The Contractor shall submit the proposed changes to the Engineer with an analysis of the need for the change. The Engineer will forward the proposed change to the Materials and Tests Engineer for approval.
c.Submittal of a Proposed Job Mix Design by th e Contractor. The Contractor shall submit a proposed Job Mix Design no later than 21 Calendar Days after the date of Notice to Proceed. The Department will be allowed 21 Calendar Days to complete the verification and approval of the Job Mix design. The co mposition of a Job Mix Design submitted by the Contractor shall be established in accordance with the requirements given in ALDOT 416, "Laboratory Design of Soil -Cement and Full -Depth Reclamation Mixes". More than one Job Mix Design may be required due to the variability of the existing roadbed materials. Each proposed Job Mix Design and samples of the roadbed materials for each design shall be submitted for evaluation and approval.
302.03 Construction Requirements.
The Contractor shall submit five copies of each proposed Job Mix Design to the Materials and Tests Engineer for approval. . All of the requirements given in ALDOT 416 shall be addressed in the Contractor's submittal of the Job Mix Designs. Construction of full depth reclamation shall not begin until the Engineer returns a copy of each approved Job Mix Design to the Contractor. The Contractor shall submit 75 pounds of composite representative samples of the existing roadbed materials and 5 pounds of the cement proposed for each proposed Job Mix Design. The Contractor shall sample t he existing roadbed materials at least every 1000 feet along the roadbed. Samples shall be obtained from all layers to be reclaimed. These materials shall be submitted to the Materials and Tests Engineer with the Job Mix Design submittal.
d.Quality Co ntrol. The Contractor shall provide and maintain a quality control system to provide assurance that the full depth reclamation is constructed in accordance with the contract requirements. The Contractor shall submit six copies of a "Quality Control Plan for Full Depth Reclamation" to the Engineer for review prior to the preconstruction conference. This plan shall include the following minimum requirements: • The procedure, equipment, and frequency for monitoring the amount of cement placement. • The proc edure, equipment, and frequency for monitoring the material characteristics of the reclaimed material. • The procedure, equipment, and frequency for monitoring the amount of water, and depth of pulverization of the reclaimed material during mixing. • The proce dure, equipment and frequency for monitoring the reclaimed material moisture during production. • The procedure, equipment and frequency for monitoring the density and moisture content of the in- place full depth reclamation. • List of all equipment to be used during the construction of full depth reclamation. • Production rates. • The procedure for correcting problems such as equipment breakdown, weather related failures, and poor workmanship as determined by the Engineer • The procedure and equipment for repairing full depth reclamation no meeting the project requirements. • Other information requested by the Engineer during the Pre -Construction conference. The Contractor shall present weekly documentation to the Engineer that the work is being monitored in accordanc e with the requirements given in the quality control plan. The Engineer will not approve the Contractor's "Quality Control Plan for Full Depth Reclamation" but will review it for completeness. An incomplete plan will be returned to the Contractor. Construc tion shall not begin until the Engineer returns one copy of the plan to the Contractor and informs the Contractor in writing that no further information will be required. The Engineer will stop the production of full depth reclamation if the Contractor does not perform the work in accordance with the submitted plan.
e.Weather Limitations . All full depth reclamation operations including pulverizing, mixing, compaction, finishing, and curing shall be continuous and completed during daylight hours. No full d epth reclamation shall be constructed when the ambient temperature is below 40 ⁰ F without written permission of the Engineer. Working on full depth reclamation construction will not be allowed when it is raining or the possibility or rain is imminent. The Engineer will decide base on weather reports if the possibility of rain exists.
f.Equipment . The Engineer will prohibit the use of any piece of equipment that will not, or does not, produce acceptable results. The Contractor shall not begin the distribu tion of the cement until the Engineer informs the Contractor that the proposed equipment and method of monitoring cement placement is adequately described in the quality control plan.
302.03 Construction Requirements.
Equipment shall include a mechanical cement spreader of a type that has an adjustable rate of flow and will distribute the cement uniformly at the required rate in one pass. Pneumatic distribution of cement is prohibited. A mechanical mixer shall be used that is capable of pulverizing and mixing the existing pavement, base an d sub -grade to the required depth. The mechanical mixer shall be capable of pulverizing the material so that 100 % passes a 2 inch sieve. The mixer shall have a metered water system for adding water directly into the mixing chamber. Water shall not be appl ied from equipment that is not a part of the mixer.
g.Length of Roadbed Allowed to be Processed . Except by written permission of the Engineer, the length of roadbed pulverized at any time shall not exceed the length that can be completely pulverized, mix ed and compacted in the same working day.
h.Initial Pulverizing and Mixing . The width and depth of the required pulverizing and mixing will be shown on the plans. The depth of pulverizing shall be controlled to insure that the finished thickness will be within the required tolerance limits. The pulverizing and mixing shall break up the existing roadbed to the extent that 100 % by weight passes a 3 inch sieve, a minimum of 95 % passes a 2 inch sieve and a minimum of 50 % passes the No. 4 sieve. The mois ture content shall be maintained within ± 2 % of the theoretical optimum moisture content unless approved otherwise by the Engineer. The Engineer will check the gradation at least once for each 2000 linear feet or fraction thereof of each lane. Preliminar y pulverization and mixing of the roadbed materials will be allowed prior to final pulverization and mixing of the roadbed materials and cement to ensure uniformity of the mixture. The Engineer will monitor the pulverization in accordance with BMT -80, “Rat e of Spread and Pulverization of Cement Stabilized Soil”.
i.Spreading of Cement . Spreading of the cement shall be done to produce a uniform distribution. The amount of cement placed shall not vary more than 5 % by weight from the approved Job Mix Design. Cement dust shall be controlled by the Contractor so that dust is kept within the confines of the construction limits. Spreading of the cement when the wind or other weather conditions are unfavorable will not be permitted. Spreading of the cement by mot or grader will not be acceptable. Cement shall be applied in a limited area so that all the operations including compaction, finishing, and curing can be continuous and completed in daylight hours, within three hours of the application of the cement. Only the equipment that is used in spreading and mixing will be allowed to pass over the spread cement before it is mixed into the existing materials. Cement that has been displaced shall be replaced before mixing is started.
j.Mixing Water with Cement and Pu lverized Materials. Water shall be mixed into the mixture of cement and pulverized roadbed materials. The addition of water and the mixing shall be completed in one continuous pass. The mixture of the water, cement, and pulverized roadbed materials shall b e within the tolerance limits of theoretical optimum moisture content and shall be suitable for immediate compaction without further mixing or grading. A gage or gages shall be provided to allow the continuous monitoring of the amount of water that is appl ied. When the mixer will handle only a part of the roadbed width within a single lane, the successive increments shall be limited in length so that a cold joint will not be formed within the lane being constructed and the full width of lane of treated material will be promptly mixed, compacted, and finished. When the moisture content of the uncompacted mixture exceeds the specified tolerance for compaction, the entire affected section shall be reconstructed at the Contractor’s expense.
k.Compaction and F inishing . The pulverizing, mixing, and compaction shall be a continuous operation. The compaction of the mixture of water, cement, and roadbed materials shall begin within 30 minutes after the final mixing. The mixture shall be compacted to 96.0% of theor etical maximum density as established in the approved Job Mix Design in accordance with AASHTO T 134. The in -place density will be measured in accordance with the requirements given in AASHTO T 310, Direct Transmission Method only. The in -place density
302.03 Construction Requirements.
will be measured at least once for each 1000 linear feet or fraction thereof of each lane. Compaction and finishing shall be completed within a period of two hours after the initial mixing of the cement. After the mixture has been compacted, the surface shall be shaped to the required lines, grades, and cross sections and within the required tolerances. During the shaping, light scarifying may be necessary to prevent the formation of compaction planes. Broom dragging or clipping of the surface may be required as a part of the process of shaping the surface during compaction. The surface material shall be maintained at the specified moisture content during finishing operations. At the end of each day’s construction, a clean, straight, vertical, transverse const ruction joint shall be formed by cutting back to the full width and thickness of completed work.
l.Testing, Tolerance, and Deficiency Correction.
1.General. Areas of the full depth reclamation that are not within the required tolerances of thickness, density, and surface finish shall be reconstructed as directed by the Engineer without additional compensation. The amount of cement required for reconstruction will be in accordance with the approved Job Mix Design.
2.Cement Spread Rate. The C ontractor shall furnish and use a square piece of canvas that is one square yard in size for checking the spread rate. The canvas shall be weighed prior to cement placement each time placement rates are checked. After weighing, the canvas shall be placed a head of the spreading operation. The canvas and cement shall be weighed after the spreader has passed over the canvas. The Contractor shall perform this measurement in the presence of the Engineer and report the measured spread rate to the Engineer. Adjust ments shall be made and repeated testing will be required to insure that the required rate is being placed. The cement spread rate shall be checked each day before beginning production placement and for each 2000 linear feet or fraction thereof of spreading in each lane. The Engineer will record the amount of cement placed in accordance with BMT- 80, "Rate of Spread and Pulverization of Cement Stabilized Soil".
3.Thickness. The thickness of the reconstructed roadbed will be checked by the Engineer at int ervals of one test per 200 feet or fraction thereof of lane, or more often if necessary. The thickness of the entire reconstructed layer or layers shall not vary by ± 1 inch from that shown on the plans. Any section deficient by more than 1 inch shall be i mmediately reconstructed in accordance with all of the requirements given in this Section for full depth reclamation. Any section out of tolerance shall have additional cement added to correct the composition of the full depth reclamation mixture and shall be remixed and recompacted to the required depth, width and density.
4.Surface Finish. The Contractor shall be responsible for roadbed grade controls. The finished surface shall not vary more than 1/4 of an inch from a 16 foot straightedge placed anywhere on the surface parallel to the centerline of the roadbed. The finished surface shall not vary more than ¼ of an inch from a 10 foot straightedge placed anywhere on the surface perpendicular to the centerline of the roadbed. The cross slope shall not vary by ± 0.50 % from the required slope as shown on the plans. The surface finish shall be checked at least twice within an intervals not to exceed 100 feet along the roadway. High spots in the finished surface may be corrected by motor grader or pla ner without additional compensation, provided the resulting thickness is within the allowable tolerances.
m.Curing . The Contractor shall cover the finished surface with a prime coat within 24 hours from completion of compaction. The prime coat shall be maintained until a pavement layer or additional surface treatment is applied. The prime coat shall be as specified in the plans and shall be placed and paid in accordance with the requirements given in Section 401.
n.Workmanship . Any subgrade deficiencie s shall be determined by the Engineer. The Contractor will be given a specific time to repair any deficiencies without any additional compensation.
o.Opening to Traffic . Completed sections of the full depth reclaimed roadbed may be opened when necessary to lightweight local traffic, provided the surface has hardened sufficiently to prevent marring or distorting of the surface, and provided the curing is not impaired. Construction equipment shall not operate on
305.03 Construction Requirements.
the full depth reclamation sections except a s necessary to discharge into the spreader during paving operations. If the full depth reclaimed roadbed is impaired by premature opening to traffic, the entire affected section shall be reconstructed at the Contractor’s expense.
302.04 Method of Measur ement.
Full Depth Reclamation will be measured in units of square yards. The length of a lane will be measured along the center of the lane. The width of a lane will be the width shown on the plans. Additional areas required for crossovers, turnouts, etc., will be determined by the measurement of the length and width along the surface of the reclaimed area. Cement will be measured in units of tons.
302.05 Basis of Payment.
a.Unit Price Coverage. The contract unit price for Full Depth Reclamation shall b e full compensation for furnishing all materials (except Portland cement and Bituminous Treatment for curing) equipment, tools, labor, and incidentals necessary to complete the work. The contract unit price for Portland cement for Roadbed Reclamation shal l be full compensation for furnishing and applying the cement to complete the work of Full Depth Reclamation. Payment will only be made for the actual amount of cement applied to the reclaimed roadbed. Additional soil or aggregate material required to con struct the roadbed to the required plan grade and section, and any unsuitable material excavated, will be measured and paid for under the appropriate item of Unclassified Excavation or Borrow.
b.Payment will be made under Item No.: 302-A Full Depth Reclamation, ___ inches Thick - per square yard 302-B Portland Cement for Full Depth Reclamation - per ton SECTION 305 SOIL AND AGGREGATE MATERIALS FOR MISCELLANEOUS USE
305.01 Description.
This Section shall cover the work of furnishing and incorpora ting a soil or aggregate material of the type specified into the work at the locations shown on the plans or designated by the Engineer. The type material may be a local material, such as borrow or selected soil, or commercial material, such as crushed aggregate, or any combination thereof to produce a material consistent with the requirements of the type material specified. The intent of this Section is to provide a material for use in localized areas for patching, leveling, or minor widening wo rk. Layers of material of a nominal depth and width should be placed under the appropriate Section of the Standard Specifications.
305.02 Materials.
All materials furnished for use shall comply with the requirements of the appropriate sections of the Stand ard Specifications, except as modified by the plans or proposal. Special attention is directed to Sections 210 and 820 through 825.
305.03 Construction Requirements.
a.General . The work of placing the material in this Section includes surface preparation including the scarification of the existing material, the addition of the material, and the processing of the new material with the existing material to form an installation meeting plan requirements.
b.Surface Preparation . Surface preparation shall inc lude any work necessary to clean the surface of the area on which the new material is to be placed, along with scarifying the surface of the existing material to promote an acceptable bond of the new and old material.
Source: Alabama Standard Specifications for Highway Construction, 2022 Edition. Pages 168–171 of 934.