Sec.6 - Construction

6.1 General

6.1.1

The Construction Engineer shall be responsible to the WCRC for ongoing liaison with construction contractors, and shall be available on a regular basis for consultation with WCRC staff.

6.1.2

The Construction Engineer shall coordinate utility installation and relocations so that completed road and drainage improvements are not damaged.

6.1.3

The Construction Engineer shall set and check grade and alignment, conduct tests and furnish test slips and material certifications from suppliers to the WCRC of materials incorporated in the road and drain construction, and supervise the inspection of all construction in the right-of-way and drainage easements.

6.1.4

Any field changes to the approved plans and specifications deemed necessary due to unforeseen circumstances encountered during construction shall be submitted to the WCRC for approval before the work begins. If work is performed without approval, the work may need to be redone, in accordance with WCRC requirements. Costs associated with such work shall be the responsibility of the Developer. All field changes shall be illustrated and/or noted on the as constructed drawings.

6.1.5

The Construction Engineer shall provide a certificate of satisfactory construction following each stage of construction. A Permit-to-Place from the WCRC will be required prior to each succeeding stage of construction. A copy of the Permit-to-Place form can be found in the Appendix (Figure 36).

6.1.6

The Construction Engineer must submit any proposed changes in the approved construction plans or specifications in writing, and written approval from the WCRC must be obtained before construction proceeds on the revised plan.

6.1.7

The Developer shall be responsible for the maintenance of all roads and drainage systems throughout the construction period and prior to acceptance of the roads by the WCRC. The Developer shall maintain the roadway surface in a safe, smooth and clean condition.

6.2 Pre-construction Meeting

A pre-construction meeting shall be held between the Developer and the Construction Engineer, the independent material sampling and testing agent, the Contractor, utility companies, representatives of the governing body, and WCRC staff. The meeting is intended to delineate the proposed construction, discuss testing requirements and progress inspections, identify haul routes, and define the sequence of construction and construction schedule.

6.3 Construction Inspection

Spot inspections will be conducted by the WCRC during construction. The Construction Engineer remains primarily responsible for setting and checking grade and alignment, documenting all construction and making all observations necessary during all phases of construction to verify that the proper materials are used, and that the work conforms to the approved plans and specifications.

6.4 Inspection and Testing

6.4.1

Inspections may be performed by the WCRC authorized representative prior to, during and after any road construction. The Developer shall allow access onto the site as a condition of the road and drainage construction plan approval. Upon completion of each of the elements in the road building process, the Construction Engineer shall request and accompany the WCRC, or County Highway Engineer representative, on an inspection of the completed construction. If WCRC and the Construction Engineer grant written approval of the completed construction, the contractor may continue with the road building process. WCRC personnel will inspect for suitability of the completed work only. WCRC inspection does not relieve the Construction Engineer of the responsibility of ensuring and certifying that the roadway is built per the approved plans and the specifications herein.

6.4.2

Copies of all independent testing results shall be forwarded to the WCRC as soon as they are available so that an evaluation can be made as to whether subsequent construction should continue or not. The independent testing agent shall inform the contractor when tests indicate that the required materials fail to meet specifications or the required density is not being achieved. Upon notice, the contractor shall alter its construction methods to meet or exceed the requirements contained herein.

6.4.3

Inspection by the WCRC shall not relieve the Construction Engineer of any of his or her obligations but will verify the proper construction of the roads in their various stages of construction by means of spot inspections during the course of construction. The Construction Engineer shall inspect grades and alignment, verify all materials incorporated into road and utility construction, arrange and supervise independent materials testing services, evaluate the test results and inspect all roadway construction so that he or she can certify that the roadways are constructed per the approved plans and the specifications herein. The following inspection notifications to the WCRC are required with at least 24-hour advance notice:

  1. Soil erosion and sedimentation control measures, tree removal, rough grading and land balancing, storm water management facilities
  2. Underground drainage and all utility installation including gas main at road crossings and conduit for the franchised utilities.
  3. Finish subgrade
  4. Install subgrade underdrain (Urban)
  5. Complete subbase
  6. Complete aggregate base course
  7. Install curb and gutter (Urban)
  8. Place pavement (HMA Base, Leveling and Top courses or PCC pavement)

6.5 Soil Erosion & Sedimentation Control

Soil erosion and sedimentation controls shall be installed and maintained in accordance with current MDOT standard plans, special details, and standard specifications for construction.

6.6 Clearing & Grubbing

All trees, stumps, brush, and roots shall be entirely removed from within the grading limits of all proposed roads and shall be disposed of outside the right-of-way.

6.7 Grading

All peat and muck shall be removed from beneath the roadway in accordance with the current MDOT Standard Plan R-103 series, Treatment of Peat Marshes, Method A-1, Total Excavation and Backfill (For Single Roadways).

6.8 Utilities

6.8.1

All utility installations shall conform to the current MDOT Standard Specifications For Construction and WCRC requirements herein.

6.8.2

All underground utilities, including lot services, shall be installed prior to subgrade approval. All underground utilities shall be stubbed to the right-of-way line or beyond.

6.8.3

The following backfill requirements shall apply to all utilities located within an area delineated by a one on one slope measured from the back of curb or the outside edge of shoulder toward the right-of-way line:

  1. Pipe bedding material shall conform to MDOT specifications or the governing body standard requirements, whichever is more stringent.
  2. All trench excavations shall be backfilled with MDOT class II or class III granular material compacted to 95% of its maximum unit weight in accordance with MDOT specifications. Where the existing soils are cohesive the top two feet will be clay compacted to 95% of its maximum unit weight. Backfill material shall be placed in lifts so that standard mechanical compaction equipment can thoroughly and uniformly achieve the stated compaction requirements. An independent testing agent shall perform material and compaction testing and the results reported to and approved by the WCRC before subgrade preparation can begin. All testing shall be performed by an independent testing agent and conform to MDOT specifications.
  3. The use of native material may be approved if an approved soils investigation report indicates that the native material meets the requirements of MDOT Class II or III granular material and if the material testing frequency and effort meets the approval of the WCRC. Material and compaction testing shall conform to the Controlled Density Method for Embankment as contained in the current MDOT Standard Specifications for Construction. An independent testing agent, throughout the backfilling operation, shall perform native material analysis and compaction testing and the results sealed by a licensed professional engineer licensed to practice in the State of Michigan. The results shall be reported in a timely manner and shall be approved by the WCRC before subgrade preparation can begin. All borrow pits must be approved by the WCRC.

6.9 Storm Sewer & Culverts

6.9.1

Shop drawings shall be submitted to the WCRC for review and approval for all storm sewer, culverts and appurtenances prior to installation. Shop drawings shall include supplier certifications.

6.9.2

The construction of storm sewer, culverts and appurtenances shall conform to the approved plans and current MDOT Standard Specifications For Construction.

6.9.3

Video inspection is required for all storm sewers pursuant to the current MDOT Standard Specifications For Construction. One copy of the videotape and a written log of all damage and installation defects identified in the video shall be submitted to the WCRC for review prior to issuance of a permit to place the final pavement course.

6.9.4

Mandrel testing shall be conducted for all corrugated plastic pipe in accordance with the current MDOT Standard Specifications For Construction. Pipe with diameter reduced by 5 percent or more shall be removed and either reinstalled or replaced prior to issuance of a permit to place the final pavement course.

6.10 Subgrade

6.10.1

The finished subgrade shall be smooth and free of all topsoil, stones, stumps, organic material, muck, peat and material prone to frost heave. The finished subgrade shall be prepared in accordance with MDOT specifications. An independent testing agent shall perform material and compaction testing and the results reported to and approved by the WCRC before subbase installation can begin. All testing shall conform to MDOT specifications.

6.10.2

Upon completion of the subgrade preparation, the Construction Engineer shall request and accompany the WCRC representative on an inspection of the finished subgrade. A proof-roll will be conducted with a loaded tri-axle truck, earth scraper or front end loader with full bucket to identify areas of unstable materials. Inspection shall be conducted with a level or string line to ensure that the prepared subgrade has been constructed to the proper grade and transverse slope. If approval of the subgrade is granted through a permit to place signed by the Construction Engineer and an authorized representative of WCRC, installation of subbase material may begin. WCRC personnel will inspect the subgrade for suitability only. WCRC inspection does not relieve the Construction Engineer of the responsibility of ensuring and certifying that the roadway is built per the approved plans and the specifications herein. Sufficient construction staking shall be present so that horizontal and vertical alignment can be determined and subgrade elevations can be verified.

6.11 Subbase

6.11.1

Sand subbase shall consist of MDOT class II granular material compacted to 95% of its maximum unit weight in accordance with MDOT specifications. An independent testing agent shall perform material and compaction testing and the results reported to and approved by the WCRC before aggregate base installation can begin. All testing shall conform to MDOT specifications. At least one sieve analysis per 3,000 cubic yards of material used shall be conducted with a minimum of one sieve analysis per project. Density tests shall be taken in accordance with the MDOT sampling and testing guidelines every 1,500 square yards of roadway at varying depths to verify compaction requirements. Frequency of sieve analyses and density testing may be increased if compaction is difficult or if the subbase material characteristics show significant variability throughout the project. Conversely, frequency of sieve analyses and density testing may be decreased if consistent acceptable compaction is obtained and the subbase material characteristics remain consistent throughout the project. This also applies to granular material under the concrete curb and gutter.

6.11.2

Upon completion of subbase installation, the Construction Engineer shall request and accompany the WCRC representative on an inspection of the subbase installation. Inspection shall be conducted with a level or string line to ensure that the prepared subgrade has been constructed to the proper grade and transverse slope.

6.11.3

If written approval of the subbase from the Construction Engineer and WCRC is granted, installation of aggregate base material may begin. WCRC personnel will be inspecting the subbase for suitability only. WCRC inspection does not relieve the Construction Engineer of the responsibility of ensuring and certifying that the roadway is built per the approved plans and the specifications herein. Sufficient construction staking shall be present so that horizontal and vertical alignment can be determined and subbase elevations can be verified. Construction staking is the responsibility of the Developer.

6.12 Aggregate Base

6.12.1

Aggregate base material shall conform to MDOT specifications and as illustrated on the approved plans. Aggregate base shall be compacted to 98% of its maximum unit weight in accordance with MDOT specifications. An independent testing agent shall perform material and compaction testing and the results reported to and approved by the WCRC before preparation for pavement placement can begin. All testing shall conform to MDOT specifications. At least one sieve analysis per 1,000 tons or 600 cubic yards of aggregate base material used shall be conducted with a minimum of one sieve analysis per project. Density tests shall be taken in accordance with the MDOT sampling and testing guidelines every 1,500 square yards of roadway at varying depths to verify compaction requirements. Frequency of sieve analysis and density testing may be increased if compaction is difficult or if the aggregate base material characteristics show significant variability throughout the project.

6.12.2

Upon completion of aggregate base installation, the Construction Engineer shall request and accompany the WCRC representative on an inspection of the aggregate base installation. If written approval of the aggregate base is granted by the Construction Engineer and a WCRC authorized representative, preparation for pavement placement may begin. WCRC personnel will inspect the aggregate base for suitability only. WCRC inspection does not relieve the Construction Engineer of the responsibility of ensuring and certifying that the roadway is built per the approved plans and the specifications herein. Sufficient construction staking shall be present so that horizontal and vertical alignment can be determined and aggregate base elevations can be verified. Construction staking is the responsibility of the Developer.

6.13 Curb & Gutter

6.13.1

Roadway cross-section elements, back of curb elevations and standard WCRC curb and gutter details shall be shown on the plans. Materials and methods for construction of concrete curb and gutter shall conform to MDOT specifications and shall include two continuous half-inch (1/2”) diameter deformed reinforcing bars. An independent testing agent shall perform material testing and the results reported to and approved by the WCRC before paving can begin. Verification of proper base installation and compaction, air tests, slump tests and strength tests of concrete shall conform to the MDOT sampling and testing guidelines. At least one series of concrete tests shall be performed per day during concrete placement. During “all day” pours, concrete tests shall be performed at least once in the A.M. and once in the P.M.

6.13.2

WCRC personnel shall be given a minimum of 48 hours notice of intent to place concrete curb and gutter. Placement of concrete curb and gutter shall not commence until the Construction Engineer has approved the line and grade of the curb and gutter.

6.13.3

Expansion joint material shall be placed at all spring points, at 400-foot maximum intervals as measured along the back of curb and gutter, and in adjacent contraction joints each side of a catch basin. Contraction joints shall be located at 10-foot intervals.

6.13.4

Horizontal sawing of curb cuts on straight back curbs is allowed provided the finished curb cut conforms to the geometric requirements of MDOT Standard Plan Series R-29.

6.14 Hot Mix Asphalt Pavement

6.14.1

HMA production and placement shall conform to MDOT specifications, this document and the approved plans. HMA shall be compacted to 97% of the theoretical maximum density from the job mix formula in accordance with MDOT specifications or as contained herein. An independent testing agent shall perform material and compaction testing and the results reported to and approved by the WCRC before further paving can begin. All testing shall conform to MDOT specifications.

6.14.2

WCRC personnel shall be given a minimum of 48 hours notice of intent to place HMA pavement. Placement of HMA shall not commence when the existing aggregate base is frozen or the pavement surface temperature is below 40 degrees Fahrenheit. Paving shall occur only between May 5 and November 15 of any year. Should the Developer wish to pave before or after these dates, written requests must be submitted to WCRC and approved by an authorized representative. Requests to pave will not be granted after December 1 unless approved by the Board. All paving operations shall comply with MDOT specifications.

6.14.3

HMA placement shall not exceed an application rate of 330 lbs. per square yard for any single lift of base or leveling course unless approved by the WCRC.

6.14.4

HMA placement shall not exceed an application rate of 220 lbs. per square yard for any single lift of top course unless approved by the WCRC.

6.14.5

Pavements to receive additional lifts of HMA pavement shall be swept clean of all dirt, dust, grit and other loose material prior to application of the HMA bond coat.

6.14.6

Butt joints shall be provided at connections to existing paved roads

6.14.7

The independent material sampling and testing company shall conduct at least one extraction test per course of HMA mixture placed in a day or one extraction test per 1,000 tons of mixture placed.

6.15 Portland Cement Concrete Pavement

6.15.1

PCC pavements shall conform to MDOT specifications, this document and the approved plans. An independent testing agent shall perform material testing and the results reported to the WCRC in a timely manner. All testing shall conform to MDOT specifications.

6.15.2

WCRC personnel shall be given a minimum of 48 hours notice of intent to place PCC pavement. Placement of PCC pavement shall not commence unless the ambient air temperature is at least 25 degrees Fahrenheit and the concrete temperature no more than 90 degrees Fahrenheit. The contractor shall provide cold weather, hot weather and rain protection, as directed by the WCRC, to protect the concrete from environmental damage during curing.

6.15.3

Integral curb and gutter may be allowed if approved by the WCRC.

6.16 Turf Establishment

All areas lacking acceptable vegetative growth within the right-of-way shall be top soiled, seeded, fertilized and mulched. The methods and time of seeding and mulching shall be in accordance with MDOT specifications. All disturbed areas within the road right-of-way shall be covered with a minimum of three inches (3”) of topsoil. Vegetative cover shall be established, to the WCRC satisfaction, on all ditches and drainage courses within the right-of-way before the roads are accepted into the County road system.

6.17 Construction Within the Existing Road Right-Of-Way

Construction activities within existing County road right-of-way are allowed only in accordance with and subject to the terms and conditions of the current WCRC Procedures and Regulations For Permit Activities and permits issued thereunder. Such work typically involves the construction of by-pass lanes, turn lanes, shoulder additions, underground utilities, drainage facilities and intersection construction. Typical details illustrating road approaches can be found in the Appendix (Figures 22 through 29).