612-1.1 The work shall consist of incorporating and blending or mixing an admixture with the type of subgrade, subbase, base, or surface course specified or as designated by the engineer.

The methods of incorporation shall be governed by the type of admixture used and by the type of course to which it is added.

MATERIALS

612-2.1 ADMIXTURE. The admixture used shall meet the following requirements:

The flaked calcium chloride shall conform to the requirements of the A. S. T. M. Designation D-98. The rate of application of calcium chloride shall be between one-half (2) percent and one and onehalf (12) percent by weight.

The stabinol shall be a resinous compound of uniform composition, and capable of waterproofing soil and soil blends. The material shall be in powdered form and be easy to handle and to distribute. The rate of application of stabinol shall be between one-half (1⁄2) percent and one and one-half (12) percent by weight.

The admixture shall be in a loose condition, and not caked or solidified, so that it cannot be readily spread by equipment intended for that purpose.

612-2.2 SOILS, SOIL BLENDS OR AGGREGATES. The soils, soil blends, or the aggregates which compose the subgrades, subbases, bases, or surface courses with which the admixture is to be mixed shall be designated in the proposal, by other specifications, or by the engineer.

The requirements of these materials will be included in other specifications, or the materials shall be as they exist in the natural condition either before or after grading operations.

CONSTRUCTION METHODS

612–3.1 WEATHER LIMITATIONS. The placing of admixtures and operations thereof shall be carried on only when the weather is suitable, when the surface is not wet or saturated, and when the atmospheric temperature is above 40° F. These requirements shall not be waived, unless directed by the engineer.

612-3.2 EQUIPMENT. Before the work is started all methods, equipment, tools, plants, and machinery employed or used in executing any part of this work shall be subject to the approval of the engineer. Items found unsatisfactory shall be changed or improved as required. All equipment, tools, machinery, and plant used must be maintained in a satisfactory working condition.

Road machines shall weigh not less than three (3) tons, shall have a wheel base not less than fifteen (15) feet and a blade not less than ten (10) feet. Road machines shall not be pulled with rollers. Motor patrols weighing not less than six (6) tons, with ten (10) foot minimum blades may be used in lieu of road machines.

Provision shall be made by the contractor for furnishing water at the plant or at the site of the work by equipment of ample capacity and of such design as to assure uniform application.

The mechanical spreader, when required for distribution of the admixture, shall be equipment similar to a chip-spreader, a limespreader, or similar approved device which will place the admixture uniformly and at the rate directed. The range of application shall be from one-half (2) to five (5) pounds per square yard.

If an admixture is to be incorporated and mixed with a material that is being processed or mixed by a central processing plant or a travel plant, such equipment shall be capable of storing, handling, measuring, and placing the admixture in the manner and quantity specified and as required.

The mixing equipment shall be designed, constructed, operated, and of the capacity so as to thoroughly incorporate the admixture with the materials.

For in-place mixing this equipment may consist of a rotary tiller or a mixing unit which combines pulverizing, blending, liquid application, and complete mixing with a single pass. Other types of mixing equipment can be used when the intended incorporation and mixing is obtained, and when approved by the engineer.

612-3.3 CENTRAL OR TRAVEL PLANT MIXING. When any material in which the admixture is to be incorporated is being processed or mixed in a central or travel plant, the admixture shall be measured and placed with the material prior to mixing. In the mixing process the admixture shall be thoroughly blended and mixed with the material. The kind and amount of admixture added shall be as given in the proposal. The moisture content of the material at the time of processing shall be such as to permit complete dispersement. After the processing, the material shall be placed, spread, and compacted as the material specification requires. The treated material shall be placed, spread, and compacted within a definite period of time when there is some reaction due to the presence of the admixture, when there is any loss in the quantity or quality of the admixture, or when there is likely to be a loss or gain in the moisture content. 612-3.4 PREPARING THE COURSE. The course in-place that is to be treated shall be spread to the proper thickness, grade,

and contour, and approved by the engineer. If the material is or has become compacted, it shall be scarified as directed to a uniform specified depth. Any depressions or high places shall be reshaped. The material shall be at the moisture content, as directed by the engineer, or brought to that content either by adding water or by aeration to permit the thorough mixing of the admixture.

612-3.5 SPREADING. When the admixture is handled in flake or powder form, it shall be spread by a suitable mechanical spreader. The spreader shall apply the admixture at a uniform and prescribed rate given in the proposal.

612–3.6 MIXING. When required to mix the admixture for a specified depth of three (3) inches or more, the mixing shall be accomplished by the required equipment, such as a rotary-tiller or similar approved equipment. The total surface area shall be covered by the mixer. The moisture content of the in-place material shall be such that complete distribution of the admixture is obtained.

When required to mix the admixture for a partial depth of two and one-half (22) inches or less, the procedure shall be accomplished by pulverizing equipment, such as a harrow, disc, or similar approved apparatus. Care must be exercised that the admixture is not mixed below the desired depth.

Immediately after the admixture has been distributed, it shall be mixed with the in-place material to the depth required. Mixing shall be continued for as long a period and repeated as often as may be necessary to insure a uniform mixture throughout. The moisture content of the material shall be such as to secure complete dispersement. The treated material shall be struck off or bladed to a smooth surface and compacted within a designated period when directed by the engineer.

612-3.7 COMPACTION. After the mixing is complete, the course shall be compacted by rolling. The rolling shall be continued until the density of the material meets the density requirements as specified for the course. No payment shall be made under this item of admixture for compaction directly, but shall be considered as a subsidiary obligation under other items of of the contract.

METHOD OF MEASUREMENT

612-4.1 The unit of measurement for the admixture shall be the pound or the ton, whichever is called for in the proposal, and which is used as ordered in the accepted work.

BASIS OF PAYMENT

612-5.1 The quantity of admixture, determined as provided above, shall be paid for at the contract unit price per pound or per ton in the bid schedule, which price and payment shall constitute full compensation for furnishing, delivering, and placing the admixture; for measuring, incorporating, and mixing when processed by plant

methods; for measuring, spreading, and mixing for in-place methods; for any blading or scarifying; and for all labor, equipment, tools, and incidentals necessary to complete the application.

The price and payment, stipulated above or elsewhere in the contract for other items of work, shall constitute full compensation for all watering, except that when the bid schedule contains an estimated quantity for watering of the course. Any authorized watering shall be paid for as provided.

Payment will be made under:

Item P-612-5.1 Admixtures-per pound or per ton.

DRAINAGE PIPE

ITEM D-701

CLAY PIPE FOR STORM SEWERS
AND CULVERTS

DESCRIPTION

701-1.1 This item shall consist of vitrified clay pipe of the types, classes, sizes, and dimensions required on the plans, furnished and installed at such places as are designated on the plans and profiles, or by the engineer in accordance with these specifications and in conformity with the lines and grades given.

The item shall include in the bid price per linear foot of pipe in place, the cost of common excavation and backfill, the cost of furnishing and installing all trench bracing, all fittings required to complete the pipe drain as shown on the plans; and the material for and the making of all joints, including all connections to existing drainage pipes and structures.

MATERIALS

701–2.1 GENERAL. The pipe shall be of the type called for on the plans or in the proposal, and shall be in accordance with the following appropriate requirements. When the plans or the proposals permit a choice of pipe, the contractor shall indicate in the bid the type proposed to be furnished.

701-2.2 VITRIFIED CLAY PIPE. Vitrified clay pipe shall conform to the requirements of A. A. S. H. O. Specification M-65. Standard strength clay pipe may be used to provide drainage outside the airport boundary. Standard strength clay pipe shall be restricted to installations on Class 1 and 2 airports.

701-2.3 MORTAR. Mortar for pipe joints and connections to other drainage structures shall be composed of one part by volume of Portland cement and two parts of mortar sand. The Portland cement shall conform to the requirements of A. S. T. M. Designation C-150, Type 1. The sand shall conform to the requirements of A. A. S. H. O. Specification M-45. Hydrated lime may be added to the mixture of sand and cement in an amount equal to fifteen (15) percent of the weight of cement used.

701-2.4 CONCRETE. Concrete for pipe cradles shall conform to the requirements of Item P-610.

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