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2001-04-25 Street Construction Specs -T able of Contents -'" I I I I I I I I I I I I I I I I I I I STREET CONSTR UCTION SPECIFICA TIONS 1.0 Scope 2.0 Grading 3.0 Clearing of Street Right of Way 4.0 Aggregate Base 5.0 Bituminous Base Course 6.0 Bituminous Wear Course 7.0 Haul Slips 8.0 Construction Observation & Testing 9.0 Cleanup Revised 4/25/01 I 2 I I the "Specified Density Method". I Density tests shall be taken to evaluate the compaction achieved. The quantity of tests shall be determined by the Engineer in the field. I Where density tests are taken to evaluate the compaction, the fill shall meet the requirements of a minimum of 100% of Standard Proctor Density (AASHTO T-99) in the upper three feet of the embankment and a minimum of 95% of Standard Proctor Density below the upper three feet. At the time of compaction, the moisture content of the backfill material shall be not less than 75%, nor more than 125%, of "optimum", the Engineer may, at his discretion, revise the compaction requirements. I The Engineer reserves the right to reject materials which are over "optimum" moisture content. 1 Sub grade excavation is further defined under Section 2.06 of these specifications. Granular borrow and select granular borr.ow shall meet the requirements of MnDOT Specification ~o. 3149; maximum particle size to be six inches in diameter. I. 1 2.04 TEST ROLliNG (2111 MODIFIED) After the above work relative to compaction is completed, the sub grade shall be test-rolled in accordance with MnDOT Specification No. 2111, except as follows; 1 A. Test rolling shall be performed prior to, intermittently during, and after completion of subgrade preparation (2112) or subgrade excavation work (2105) when ordered by the En~ineer. The limits of yielding or rutting portion of this Specification 2111.3 shall apply only to the test roll for final acceptance of the sub grade preparation; earlier test rolling shall be for the purpose of identifying those areas needing sub grade excavation, etc. Later test rolling on the aggregate base course shall be to determine if required stability and density exists. The "required stability" shall be such that when test rolled, the surface shows yielding or rutting of no more than 1 \1" measured from the top of the constructed grade to the bottom of the rut. The "required density" shall be 100% Standard Proctor. I I 1 In embankmentlfill areas, the subgrade may be test rolled at an elevation lower than finished subgrade elevation if the condition of the soils being placed indicate that normal sub grade preparation (2112) cannot be performed and that subgrade excavation (2105) may be necessary; this procedure is to eliminate having to remove materials just previously placed. Test rolling shall also be used in conjunction with the placing of aggregate or bituminous base courses when ordered by the Engineer. The sub grade shall pass the test rolling prior to placement of the aggregate base and the aggregate base shall pass the test rolling prior to placement of the curbing or bituminous base. I I B. The Contractor will furnish a wheel loader (with operator) or other equipment approved by the Engineer for test rolling. The wheel loader shall have an approximate bucket size of three cubic yards and shall be fully loaded. Test rolling will be required over the entire length and width of the proposed roadway and one foot outside the back of curb. Test rolling shall be performed as many times as deemed necessary by the Engineer. The costs of the wheel loader and operator and any other costs incurred during test rolling shall be incidental to construction of the subgrade or base and no direct compensation will be made therefore. Test rolling, including re-testing of repaired, failed sections, shall also be considered as incidental. I 1 I 2.05 SUBGRADE PREP ARA nON (2112) The subgrade shall be prepared in accordance with MnDOT Specification 2112, except as follows: I The Contractor shall have the option, at his discretion, to choose one of the methods described below for I d I I prior to attempting subgrade preparation, subgrade soil removal (top 12"), and test rolling. I All excavation shall be by the load and haul method, in an attempt not to disturb the already questionable stability of the virgin soils below the sub-cut. Common excavation, common borrow, granular borrow, or base materials, when used in replacing materials removed through subgrade excavation, shall be as follows: I A. Common Excavation Material (2105.2A) Common excavation material to be used in sub grade excavation must be approved by the Engineer prior to placing. When this material is used, the Contractor shall be paid for both excavation of the unsuitable materials and replacement of the unsuitable materials with common excavation, at the common excavation unit price, provided the common. excavation material is furnished from an initial excavation area. If the common excavation material has been moved once initially and stockpiled, then the material will bepaid as common borrow material, as described below. The excavation and replacement are both paid through the unit bid price of the material used for replacement. I I I B. Common Borrow Material (210SB) _- When suitable or ample common excavation material cannot be found within the excavation ~its, the common borrow material approved by the Engineer will be used in subgrade excavation. Borrow material will be obtained within the right-of-way if available; it not, it may be obtained off the right-of-way at a location located and negotiated by the Contractor and Engineer. Regardless of the location of the borrow source, only one bid item will apply for furnishing of the borrow. When common borrow is used, the Contractor shall be paid for both excavation of the unsuitable materials and replacement of the unsuitable materials with common borrow, at the common excavation unit price. The excavation and replacement are both paid through the unit bid price of the material used for replacement. I I I C. Granular Borrow Material (3149) When common excavation or common borrow material cannot be obtained by the contractor on or off the right-of-way, the Engineer may direct the Contractor to use granular borrow material for sub grade excavatlOn. I I When granular borrow is used, the contractor shall be paid for both replacement of the unsuitable materials and excavation of the unsuitable materials with granular borrow at the granular borrow unit price. The excavation and replacement are both paid through the unit bid price ofthe material used for replacement. I All materials used for replacement in areas of sub grade excavation shall be compacted in accordance with 2105, as previously mentioned in Section 2.03. I Payment for subgrade excavation shall be by the original in-place cubic yard (c.y.) and shall be compensation for excavation, disposal of the material, and placement of suitable soils at material unit cost. I INCLEMENT WEATHER; No subgrade excavation shall be used to correct conditions caused by inclement weather. In cases where inclement weather is continuous and for long periods of time, and does not allow for expeditious completion of subgrade preparation by use of 2112,2105, and/or Section 2.05, the Engineer may require the Contractor to prepare the roadways as follows: I A. Make a core excavation of the subgrade to a depth as directed by the Engineer. I B. Replace the excavated material below subgrade with the same materials to be used for base material (Class 5 etc.) and then immediately continue to place the loose material in the area above the subgrade elevation. The sub grade excavation and the base course both shall be constructed with base material in a fashion which will contribute to "bridging". In this case, after the subgrade excavation has been made and I I r o I I Gravel material shall be of the class designated on the typical section of the Plans. Gravel material shall meet the requirements of Section 3138 of MnDOT Specifications for Highway Construction, 1988 Edition, except as modified hereafter. I I 4.03 TESTING Samples of the aggregate base material shall be taken at the project site at the r:lte of one test for every 1000 feet of base (minimum). A minimum of two tests shall be required on the project. An independent lab shall perform the tests and confirm the gradation. All test reports shall indicate the location where the samples were taken. The gravel shall meet Class 5 gradation requirements prior to the placement of curbing or bituminous application. I I I 4.04 COMP AcnON Compaction shall be by the "Specified Density Method." Tests shall be taken at the rate of one (1) test for every 100 feet of aggregate placed. Testing shall be by an independent test lab and shall be paid for on a per-test basis. Re- testing shall not be paid for. The base material shall be compacted to 100% of Standard Proctor Density. 4.05 OUALITY CONTROL The gravel base shall be approved 24 hours before the bituminous base application. The base shall be within ~"..:t at the crown and quarter crown. I 4.06 PAYMENT Payment for the aggregate base shall be on the basis of cubic yards of material furnished and compacted in place and shall be compensation in full for all costs incidental to its construction. I I 5.00 BITUMINOUS BASE COURSE I 5.01 WORK INCLUDED The Contractor shall, unless specified otherwise, furnish all material, equipment, tools and labor for the construction of a paver-laid bituminous base as noted on the Plans, and shall be done in accordance with Section 2331 ofMnDOT Specifications for Highway Construction, 2000 Edition, except as modified below. I I 5.02 AGGREGATE The aggregate material shall meet the requirement of aggregate size B, Table 3139-1, Section 3139, for both type 31 and type 32, Base Course Mixtures, Section 2331. I 5.03 BITUMINOUS MATERIAL The bituminous material shall be asphalt cement, classified by the Performance Grading (pG) System and shall meet or exceed the requirements for PG 52-34. I The oil content shall be within plus or minus 0.3% of the amount determined by the design mix. The oil content shall meet or exceed the minimum percentages by weight identified in Table 2331-1, Section 2331, for the appropriate mixture type. Cost of the design mix shall be incidental to the payment for bituminous base. I I I 5.04 CONSTRUCTION AJl concrete curb and gutter must be backfilled before any blacktop is applied to the street. Prior to placement of the base course, any existing bituminous surface abutting it shall have a straight SaW-Cllt joint made, it shall be I 8 I 1 I Compaction shall be by the "ordinary compaction" method. Each layer shall be compacted until there is no further evidence of consolidation, using a tamping, steel-wheeled or pneumatic-tired roller, meeting the requirements of the MnDOT Specification 2123. The Engineer may elect to test the compaction with field density tests_ The wear material shall be compacted to 100% of Standard Proctor Density. I The bituminous wear course at the edge of the curb and gutter shall be 1.4" above the edge, following compaction. The additional cost of the materials along the edge shall be incidental to the cost of the wear course. I 6.05 PAYMENT The bituminous wear shall be paid for on the basis of square-yard-inch at plan thickness. Unless otherwise directed by the Engineer, all streets shall be constructed with a bituminous thickness as shown on the Plans. I Payment shall be compensation for cutting the existing bituminous, sweeping, tack coat, furnishing materials, laying and rolling. _''" 1- - At the conclusion of the project, cores in the blacktop may be ordered if, in the opinion of the Engineer, the pavement does not meet the Specifications. A minimum of one core for every 400 feet of roadway shall be taken. The following tests shall be run by an independent test lab at the Contractor's expense. I 1. Thickness 2. Marshall Density 3. Gradation 4. Extraction 5. Void Content 1 I If the Marshall density for the cores is less than the specified minimum density, then in lieu of being removed and replaced to an acceptable condition it will be accepted at a reduced rate, according to MnDOT Specification 2331.3, 2000 Edition. 1 I In addition, an average thickness of all the cores shall be computed. Based upon that thickness, payment for both the wear and base shall be adjusted according to the following schedule: a. average thickness 0.00-0.15 inches less than plan and average thickness greater than plan (except where ordered by the Engineer): payment made at unit prices. I b. average thickness: 0.16-D.25 inches less than plan; 15% reduction of unit prices as bid. 1 c. average thickness 0.26-0.50 inches less than plan: 30% reduction of unit prices as bid. d. any specific area which has a test thickness less than plan thickness minus 0.50 inches shall be replaced. I I 7.00 HAUL SLIPS "Haul slips" showing tonnage of all bituminous and rock material delivered to the job site shall be submitted to the Engineer on a daily basis. All tonnage tickets shall be wei~hed and not estimated. I Unless the method of payment called for on the proposal is by the ton, all haul slips supplies will be used for verification or the cubic yard or square yard quantities only. 1