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R-80-276 - 1/24/1980RESOLUTION N0. ' 7 7 BE IT RESOLVED by the City Council of the City of Round Rock, Texas that Item 203 in the construction specifications as adopted on December 13, 1979 be revised as attached hereto and labeled "City of Round Rock, Item No. 203, Lime Treatment for Materials in Place, Revised January 24, 1980:', and that said revised item be and is hereby adopted. RESOLVED this 24th day of January, 1980. s Ail L RY L. To , Ma or.' City of Round Rock, Texas ATTEST: JO NE LAND, City Secretary Coring Thickness determinations shall be made in accordance with SDHPT Test Method Tex - 424-A or other methods approved by the Engineer. 203.8 Payment Work performed and materials furnished as prescribed by this item and measured as provided under "Measurement" will be paid for as follows: Lime will be paid for at the unit price bid per ton of 2000 pounds for "Lime." "Lime Treated Subgrade," "Lime Treated Existing Subbase" and "Lime Treated Existing Base," will be paid for at the unit price bid per square yard. The unit prices bid shall each be full compensation for preparing the roadbed; for furnishing all materials; for all freight involved; for public scales weighing charges or for furnishing scales and labor involved in weighing the material; for loosening, mixing, pulverizing, spreading, drying, application of lime, sprinkling, rolling, shaping, maintaining; and for all- manipulations, labor, equipment, fuels, tools and incidentals necessary to complete the work. Payment will be made under: Pay Item No. 203 -A: Lime treated subgrade -Per Square Yard. Pay Item No. 203 -B: Lime treated existing subbase -Per Square Yard. Pay Item No. 203 -C: Lime treated existing base -Per Square Yard. Pay Item No. 203 -D: Lime -Per Ton. CITY OF ROUND ROCK Item No. 203 Lime Treatment for Materials in Place Revised January 24, 1980 203.1 Description This item shall consist of treating the subgrade, existing subbase or existing base by the pulverizing, addition of lime, mixing and compacting the mixed material to the required density. This item applies to natural ground, embankment, or existing pavement structure and shall be constructed as specified herein and in conformity with the typical sections, lines and grades as shown on the plans or as established by the Engineer. 203.2 Materials - 1. "Hydrated Lime and Lime Slurry" named or referred to in this item shall meet and be the same as the types and grades specified in the State Depart- ment of Highways and Public Transportation, Item 264, entitled "Hydrated Lime and Lime Slurry" from their 1972 Standard Specifications for Construction of Highways, Streets and Bridges. 2. When Type B, Commercial Lime Slurry, is specified, the Contractor shall select, prior to construction, the grade to be used and shall notify the Engineer in writing before changing from one grade to another. 3. If the minimum design strength or the percent of lime to be used for the treated subgrade, existing subbase or existing base is specified, preliminary tests -for substantiation shall be performed in accordance with SDHPT Test Method Tex - 121 -E. In no case shall the amount of lime used in construction be less than that recommended in Fig. 3 of that test method, but may be more depending on Tex -121 -E test results. 4. It is the intent of this specification that the subgrade soil, subbase or existing base which is to be lime stabilized, be substantially free of organic matter such as concentrations of weeds, grass, leaves, rotting wood and other such organic matter deleterious to all kinds of soil stabilization, be removed, wasted and not included in the pavement sections or in the secondary subgrade. 203.3 Equipment 1. The machinery, tools and equipment necessary for proper prosecution of the work shall be on the project and approved by the Engineer prior to the beginning of construction operations. All machinery, tools and equipment used shall be maintained in a satisfactory and workmanlike manner. 2. Hydrated lime shall be stored and handled in closed weatherproof containers until immediately before distribution on the street. If storage bins are used they shall be completely enclosed. Hydrated lime in bags shall be stored in weatherproof buildings with adequate protection from ground dampness. 3. If lime is furnished in trucks, each truck shall have the weight of lime certified on public scales or the Contractor shall place a set of standard platform truck scales or hopper scales at a location approved by the Engineer. 4. If lime is furnished in bags, each bag shall bear the manufacturer's certified weight. Bags varying more than 5 percent from the weight may be rejected and the average weight of bags in any shipment, as shown by weighing 50 bags taken at random, shall not be less than the manufacturer's certified weight. 203.4 Construction Methods 1. General It is the primary requirement of this specification to secure a completed course of treated material containing a uniform lime mixture free from loose or segregated areas, of uniform density and moisture content, well bound for its full depth and with a smooth surface suitable for placing subsequent courses. It shall be the responsibility of the Contractor to regulate the sequence of his work, to use the proper amount of lime, maintain the work and rework the courses as necessary to meet the above requirements. The street subgrade shall be constructed and shaped to conform to the typical sections, lines and grades as shown on the plans or as established by the Engineer.The material, either before or after lime is added, shall be excavated to the secondary grade (proposed) bottom of lime treatment) and removed or windrowed to expose the secondary grade. Any wet or unstable materials below the secondary grade shall be corrected, as directed by the Engineer, by scarifying, adding lime and compacting until it is of uniform stability. If the Contractor elects to use a cutting and pulverizing machine that will remove the subgrade material accurately to the secondary grade and pulverize the material at the same time, he will not be required to expose the secondary grade nor windrow the material. However, the Contractor shall be required to roll the subgrade, as directed by the Engineer, before using the pulverizing machine and correct any soft areas that this rolling may reveal. This method will be permitted only where a machine is provided which will insure that the material is cut uniformly to the proper depth and which has cutters that will plane the secondary grade to a smooth surface over the entire width of the cut. The machine shall be of such design that a visible indication is given at all times that -the machine is cutting to the proper depth. 2 Application Lime shall be spread only on the area where the first mixing operations can be completed during the same working day. The application and mixing of lime with the material shall be accomplished by the methods hereinafter described as "Dry'Placing" or "Slurry Placing." • (a) Dry Placing (When approved by the Engineer.) The lime shall be spread by an approved spreader or by bag distribution at the rates shown on the plans or as directed by the Engineer. The lime shall be distributed at a uniform rate and in such manner as to reduce the scattering of lime by wind to a minimum. Lime shall not be applied when wind conditions, in the opinion of the Engineer, are such that blowing lime becomes objectionable to traffic or adjacent property owners. A motor grader will not be used to spread the lime. The material shall be sprinkled as directed by the Engineer, until the proper moisture content has been secured. (b) Slurry Placing The lime shall be mixed with water in trucks with approved distributors and applied as a thin water suspension or slurry. The distribution of lime at the rates shown on the plans or as directed by the Engineer shall be attained by successive passes over a measured section of roadway until the proper moisture and lime content has been secured. The distributor truck shall be equipped with an agitator which will keep the lime and water in a uniform mixture. 3 Mixing The mixing procedure shall be the same for "Dry Placing" or "Slurry Placing" as_hereinafter described. (a) First Mixing The material and lime shall be thoroughly mixed by approved road mixers or other approved equipment, and the mixing continued until, in the opinion of the Engineer, a homogeneous, friable mixture of material and lime is obtained, free from all clods or lumps. Materials containing plastic clays or other material which will not readily mix with lime shall be mixed as thoroughly as possible at the time of the lime application, brought to the proper moisture content and left to cure 1 to 4 days as directed by the Engineer. During the curing period the material shall be kept moist as directed. (b) Final Mixing After the required curing time, the material shall be uniformly mixed by approved methods. If the soil binder -lime mixture contains clods, they shall be reduced in size by raking, blading, discing, harrowing, scarifying or the use of other approved pulverization methods so that when all nonslaking aggregates retained on the No. 4 sieve are removed - the remainder of the material shall meet the following requirements when tested dry by laboratory sieves: Percent Minimum Passing 1 -3/4" Sieve 100 Minimum Passing No. 4 Sieve 60 During the interval of time between application and mixing, hydrated lime that has been exposed to the open air for a period of 6 hours or more or to excessive loss due to washing or blowing will not be accepted for payment. 4. Compaction Compaction of the mixture shall begin immediately after final mixing and in no case later than 3 calendar days after final mixing, unless approval is obtained from the Engineer. The material shall be aerated or sprinkled as necessary to provide the optimum moisture. Compaction shall begin at the bottom and shall continue until the entire depth of mixture is uniformly compacted. If the total thickness of the material to be treated cannot be mixed in one operation, the previously mixed material shall be bladed to a windrow just beyond the area to be treated and the next layer mixed with lime as specified in Number 3. The first layer of the treated material shall be compacted in such a manner that the treated material will not be mixed with the underlying material. The course shall be sprinkled as required and compacted to the extent necessary to provide the density specified below as determined by the use of the compaction ratio method: Description For lime treated subgrade, existing subbase or existing base that will receive subsequent subbase or base courses. For lime treated existing subbase or existing base that will receive surface courses. Density, Percent Not less than 95 except when otherwise shown on the plans. Not less than 98 except when otherwise shown on the plans. The testing will be as outlined in SDHPT Test Method Tex -113 -E or other approved methods. In addition to the requirements specified for density, the full depth of the material shown on the plans shall be compacted to the extent necessary to remain firm and stable under construction equipment. After each section is completed, tests as necessary will be made by the Engineer. If the material fails to meet the density requirements, it shall be reworked as necessary to meet these requirements. Additional lime shall be added, at the sole expense of the contractor, when any lime stabilized soil is reworked due to insuffient densities. It shall be the sole responsibility of the Engineer either to accept the reworked section or sections, or to require new Tex -113 -E moisture - density tests to determine the new density requirements on the then, different treated sections. Throughout this entire operation the shape of the course shall be maintained by blading and the surface upon completion shall be smooth and in conformity with the typical section shown on the plans and to the established lines and grades. Should the material, due to any reason or cause, lose the required stability density and finish before the next course is placed or the work is accepted, it shall be recompacted and refinished at the sole expense of the Contractor. 203.5 Finishing, Curing and Preparation of Surfacing After the final layer or course of the lime treated subgrade, subbase or base has been compacted, it shall be brought to the required lines and grades in accordance with the typical sections. The competed section shall then be finished by rolling as directed with a pneumatic tire or other suitable roller sufficiently light to prevent hair cracking. Where continued reshaping and rolling of lime treated materials the contractor, at his option, may blade off and waste the top 3/4 inch of retempered material or he may re- sprinkle with additional lime slurry and retain the material. In any case there shall be no final reduction in section thickness due to any blading off of retempered material. The completed section shall be moist -cured for a minimum of 7 days before further courses are added or any traffic is permitted, unless otherwise directed by the Engineer. In cases where subgrade treatment or subbase sets up sufficiently to prevent objectionable damage from traffic, such layers may be opened to traffic 2 days after compaction. If the plans provide for the treated material to be sealed or covered by other courses of material, such seal or course shall be applied within 14 days after final mixing is completed, unless otherwise directed by the Engineer. 203.6 Measurement Lime treatment of the subgrade, existing subbase, and existing base shall be measured by the square yard to neat lines as shown on the typical sections. When Type A, Hydrated Lime is used, the quantity of lime will be measured by the ton of 2,000 pounds, dry weight. When Type B, Commercial Lime Slurry, is used, the quantity of lime shall he calculated from the required minimum percent solids based upon the use of Grade 1, Grade 2, or Grade 3 as follows: Grade 1: The Dry Solids Content' shall be at least 31 percent by weight of the slurry and the quantity of lime will be calculated by the ton of 2000 _pounds }.based on the 31 percent, ad delivered on the road. Grade 2: The "Dry Solids Content" shall be at least 35 percent by weight of the slurry and the quantity of lime will be calculated by the ton of 2000 pounds based on the 35 percent, as delivered on the road. Grade 3: The "Dry Solids Content" shall be at least 46 percent by weight of the slurry and the quantity of lime will be calculated by the ton of 2000 pounds based on the 46 percent, as delivered on the road. 203.7 Tolerances The Engineer may elect to accept the work, provided that not more than 20% of the density tests performed each day are outside the specified density require- ments, from SDHPT Test Method Tex -113 -E testing, by no more than 2 pounds per cubic foot and where no two consecutive tests on continuous work are outside the specified limits. Density tests shall be determined by SDHPT Test Method Tex -115 -E or by other methods approved by the Engineer. It shall be the responsibility of the Contractor as set forth under "Description" and "Construction Methods" above, to construct in accordance with the specifications herein to the typical sections, lines and grades shown on the plans or as established by the Engineer. Depth tests shall be made for total thickness prior to final acceptance of the work. Thicknesses which are within 1/4 inch of plan thicknesses shall be construed as meeting plan thicknesses. Thicknesses deficient by more than 1/4 inch but less than 1/2 inch may be accepted by the Engineer provided not more than any 300 linear feet of continuous work is found to be deficient in thickness. When pavement is found to be over 1/2 inch deficient in thickness the Contractor shall bring the section, found to be deficient, to the correct thickness laying hot -mix, hot -lay surfacing at his sole expense.