151 SECTION 301 THROUGH SECTION 306-BLANK
CRUSHED AGGREGATE BASE COURSE
307.1 -DESCRIPTION : This work shall consist of furnishing, spreading, and compacting one or more courses of crushed aggregate on a prepared surface in accordance with these Specifications and in reasonably close conformity with the lines, grades, thicknesses, and typical cross sections shown on the Plans or established by the Engineer.
307.2 -MATERIALS : The crushed aggregate base course shall be composed of materials meeting the requirements of Subsection 704.6 for the class shown on the Plans.
307.2.1 -Quality Control Testing: Quality control of the crushed aggregate base course is the responsibility of the Contractor as specified in 106.1. The Contractor shall maintain necessary equipment and qualified personnel to perform all sampling and testing necessary to determine the magnitude of the various properties of the material governed by the Specifications and shall maintain these properties within the limits of the Specifications. The Contractor shall submit a quality control plan detailing the methods by which the quality control program will be conducted. This plan, prepared in accordance with the guidelines set forth in the appropriate portions of MP 307.00.50 and MP 717.04.21, shall be submitted to the Engineer at the preconstruction conference. The work shall not beg in until the plan is reviewed for conformance with the contract documents.
307.2.2 -Acceptance Testing: Acceptance sampling and testing of crushed aggregate base course is the responsibility of the Division, except for furnishing the necessary materials . Quality control sampling and testing performed by the Contractor may be used by the Division for acceptance.
307.2.3 -Sampling and Testing: Frequency of sampling and testing shall be in accordance with the Contractor ’s quality control plan. The mini mum frequencies shall be as indicated in applicable portions of MP 307.00.50. Crushed aggregate shall be sampled in accordance with MP 700.00.06, Aggregate Sampling Procedures.
307.2.4 -Acceptance Procedure: Material conforming to the specification requirements will be accepted at full contract price. Material failing to comply with the quality requirements of Table 704.6.2B shall not be incorporated into the work. Acceptance of crushed aggregate base course for compaction and for gradation shall be in accordance with appropriate portions of subsection 307.2.4.1.
307.2.4.1 -Acceptance Plan: 307.2.4.1 .1-For Compaction: Acceptance for compaction shall be on a lot by lot basis. A lot shall consist of a si ngle layer of not more than 2,000 linear f eet per width being placed. A lot shall be divided into five approximately equal sized sublots. One nuclear
152 moisture and density measurement in accordance with applicable portions of Section 717 shall be made at a random location within each of the five sublots. The random locations shall be determined in accordance with MP 712.21.26. If the result of five density tests on a lot indicates that at least 80 percent (80%) of the material, in accordance with subsection 106.3.1 (West Virginia AP -A), has been compacted to the specified target percentage of dry density, the lot will be accepted. If less than 80 percent (80%) has been compacted to the specified target percentage of dry density, no additional material sh all be placed on that layer until it has been reworked to meet the specified requirements. Reworking and retesting shall be at the expense of the Contractor. When the Division performs the testing in the evaluation of reworked lots, the testing will be a t the expense of the Contractor at the unit cost specified in subsection 109.2.2. Compaction of shoulder aggregate on resurfacing projects adjacent to asphalt or concrete pavement shall be based on visual inspection to assure that the surface of the shoul der has been compacted to the level of the finished pavement surface. Compaction of Class 7 aggregate shall be based on visual inspection to assure that the aggregate particles are arranged in a stable manner.
307.2.4.1.2 -For Gradation: The material shall be sampled and tested in accordance with Section 307.2.3. Acceptance for gradation shall be based on test results of consecutive random samples from a lot. A sublot is the quantity of material represented by a single gradation test as defined in MP 700.00.06 . A lot shall be considered the quantity of material represented by an average test value, not to exceed five sublots. In the case where only one sample is needed for the total plan quantity, the sublot shall be considered the lot. The average shall start on the second sample result. The average is continued for the third through fifth sample result, averaging all previous sample results. Thereafter, only the last consecutive five sample results will be averaged, i.e., second tes t value through sixth test value, third test value through seventh test value, and so forth as defined in MP 300.00.51. When the test value of a lot and the test value of the last sublot, or when the last three consecutive individual test values of a lot fall outside the gradation limits of Table 704.6.2A, the lot of material represented will be considered nonconforming to the extent that the last of its sublots are nonconforming. When this occurs, the last sublot shall have its price adjusted in accordance with Table 307.9.1.
307.2.4.2 -Degree of Nonconformance: When a sublot of material is to have its price adjusted, the percentage point difference between the nonconforming test value and the specification limit shall be determined for each sieve size determined to be nonconforming, and this value shall be mult iplied by its appropriate multiplication factor as set forth in Table 307.2.4.2 to determine the degree of nonconformance on that sieve.
153 TABLE 307.2.4.2 Nonconforming Sieve Size Multiplication Factor 2 in. (50 mm) 1.0 1 ½ in. (37.5 mm) 1.0 ¾ in. (19 mm) 1.0 No. 4 (4.75 mm) 1.0 No. 40 (425 μm) 1.5 No. 100 (150 μm) 2.0 No. 200 (75 μm) 2.5
The total measure of nonconformance of an individual sublot is the sum of all nonconformances on the various sieve sizes of that sublot. When the total degree of nonconformance has been established and it is 1 6.0 or less, the material will be paid for at an adjusted contract price as specified in Table 307.9.1. When the degree of nonconformance is greater than 1 6.0, the nonconforming sublot shall b e resolved on an individual basis, requiring a special investigation by the Engineer to determine the appropriate course of action to be followed. Pending resolution of the matter, additional lifts of base or pavement shall not be placed over the nonconfo rming material.
307.2.5-Reclaimed Asphalt Pavement: Reclaimed Asphalt Pavement (RAP) may be substituted for Class 10 Shoulder Stone material on roadways where edge line pavement markings exist or are installed. Materials testing will be waived, howeve r the Top Size gradation shall not exceed 1 ½ inches (37 mm) or the maximum shoulder placement thickness as defined on the Plans (whichever is less). Approval shall be by visual inspection by the Engineer. Payment for RAP shoulder material substitution shall be at the same unit bid price for Shoulder Stone Material in the Contract documents.
CONSTRUCTION METHODS
307.3 -EQUIPMENT : Any machine, combination of machines, or equipment which will handle the material without undue segregation and produce the completed base course meeting these Specifications for handling, spreading, moistening, mixing and compacting may be used when approved by the Engineer.
307.4 -PLACING : Prior to the placing of any base course material on the subgrade, the subgrade shall meet the applicable requirements of 207.9 or 228. The profile grade of the subgrade shall be such that the specifie d thickness of the base course may be obtained. No base shall be placed when the subgrade is frozen or when it is sufficiently wet that its surface can be marred by construction equipment. The base course shall be placed and shaped on the prepared surfac e in layers to achieve the compacted thickness shown on the Plans. When more than one layer is required, each layer shall be shaped and compacted to the required density before the succeeding layer is placed. Each layer shall be kept at least 500 f eet Ahead of the succeeding layer. Tailgating will not be permitted. If
154 power graders are used for spreading, the material shall be placed in windrows and uniformly and thoroughly mixed prior to final spreading and compaction. On resurfacing projects the exis ting shoulders shall be scarified to a depth of two ( 2) inches or as shown on the Plans. Subgrade soil or ditch soil shall not be mixed with the loosened material. The loosened material shall then be broken and reshaped to form a uniform grade and cross section. Aggregate for shoulders on resurfacing projects shall be spread over the prepared surface to a width as specified in the Plans and to a depth sufficient to bring the uncompacted surface to a height of at least one ( 1) inch above the finished pavement edge elevation. For compacted shoulder thicknesses exceeding three ( 3) inches, the differential from the pavement edge elevation must be increased to assure that the loose aggregate thickness is approximately equal to 1 -1/3 times the compacted thickn ess. The loose aggregate is then to be shaped to proper grade and cross section maintaining the height differential.
307.5 -COMPACTING : Each layer shall be compacted. The moisture content shall be m aintained at a level sufficient to facilitate compaction. Required density and testing shall be in accordance with the provisions of the appropriate portions of 717. The surface of each layer shall be maintained during the compaction operations in such a manner that a uniform texture is produced and the aggregates firmly keyed. The surface of the top layer of the base course shall be carefully trued by blading if necessary. Shoulder aggregate adjacent to concrete or asphalt pavement shall be compacted b y pneumatic tire rollers when the drum roller is wider than the shoulder width or as directed by the engineer.
307.6 -TOLERANCE : 307.6.1 Surface Tolerance: The completed surface shall not vary more t han 3/8 inch above or below Plan grade, nor more than 3/8 inch from a straightedge ten ( 10) feet long applied parallel to the centerline of the pavement. Deviations shall be corrected by scarifying, adding additional approved aggregate if necessary, reshaping, and recompacting. Shoulder surfaces on resurfacing projects adjacent to concrete or asphalt pavement do not need to be checked with a straightedge.
307.6.2 -Thickness Tolerance: The base course shall be checked for proper thickne ss after final compaction. The Contractor shall refill all test holes with approved base course material and adequately recompact the material. Any deficiency in total thickness of the base course in excess of ½ in ch shall be corrected.
307.7 -MAINTENANCE: The surface of the completed base shall be protected against the loss of fine material by the addition of moisture when necessary, and it shall be maintained in a satisfactory and smooth conditio n until such time that it is surfaced or finally accepted.
307.8 -METHOD OF MEASUREMENT : 307.8.1 Cubic Yard Measurement: The quantity of work done will be the number of cubic yards measured in place. Any additional work beyond the scope of the original Plans but authorized by the Engineer will be measured in cubic yards in place and paid for at the unit bid price for this item, subject to the provisions of 104.2 and 109.2.
155 Base co urse constructed outside the lines, dimensions, and cross sections shown on the Plans or designated will not be measured for payment.
307.8.2 -Ton Measurement: The quantity of work done will be the number of tons of material complete in place and accepted. The number of tons shall be determined by the total of the weights shown on receipted railroad freight bills when materials are shipped by rail; by actual measured displacement of barges certified by the producer when water shipments are made, providing materials delivered by the methods are not stockpiled or stored; or determined by the Contractor from the total of weigh slips for each vehicle load weighed on an approved standard scale or from digital printout slips from an automatic batching plant, and certified by the Contractor to be correct. Truck scales shall be provided by the producer or Contractor, except that truck scales are not required where the material is weighed at properly calibrated automatic batching plant facilities which are equi pped with digital print -out equipment. The scales shall be of sufficient size and capacity to weigh the heaviest loaded trucks that are used for delivery of the material. All truck scales shall be mounted on solid foundations, which will insure their re maining plumb and level. All truck scales shall be inspected and sealed by the West Virginia Division of Labor, Bureau of Weights and Measures, or other appropriate agencies of the State or its political subdivisions. The Division may, at its option, acc ept inspection and sealing by out of state agencies when the material is weighed outside West Virginia. The producer shall provide a weigh person. The weigh person shall certify that the weight of the material, as determined either by the truck scales o r from the digital printout of the weights, is correct. Each truck shall be weighed empty prior to each load, except at automatic batch plants approved to operate without truck scales. A digital recorder shall be required on all truck scales. The digital recorder shall produce a printed record of the gross, tare and net weights, and the time, date, truck identification and project number. Provision shall be made for constant zero compensation and further provision shall be made so that the scales may n ot be manually manipulated during the printing process. The system shall be interlocked so as to allow printing only when the scale has come to rest. In case of a breakdown of the automatic equipment, the Engineer may permit manual operation for a reaso nable time, normally not to exceed 48 hours, while the equipment is being repaired. When reconditioning surface with aggregate is specified it shall include the cost of all surface reconditioning work.
307.9BASIS OF PAYMENT :
The quantities, determined as provided above, will be paid for at the contract unit price bid for the items listed below, which price and payment shall be full compensation for furnishing all the materials including water for compaction, scarification and manipulation of existing surface, and doing all the work prescribed in a workmanlike and acceptable manner, including all labor, tools, equipment, supplies, and incidentals necessary to complete the work.
307.9.1 -Price Adjustment: Aggregates not conforming with the gradation requirements as described in 307.2.4.1 will be paid for at the adjusted contract price based on the degree of nonconformance as specified in Table 307.9.1.
156 TABLE 307.9.1 Adjustment of Contract Price for Gradation not Within Specifications Degree of Nonconformance Percent of Contract Price to be Reduced 1.0 to 3.0 2 3.1 to 5.0 5 5.1 to 8.0 8 8.1 to 12.0 12 12.1 to 16.0 16 Greater than 16 *
* The Division will make a special evaluation of the material and determine the appropriate action.
307.10PAY ITEMS :
ITEM DESCRIPTION UNIT 307001 -* Aggregate Base Course, Class “class” Cubic Yard 307005 -* Aggregate Base Course, “aggregate type”, Class “class” Ton
* Sequence number “aggregate type” shall be either stone and gravel, slag or steel slag “class” From Table 704.6 2 A and B