King County Environmental Purchasing Program

Construction Recycling and Waste Management

• Introduction
• Usage History and Experience
• Bid and Contract Specifications
  • King County Regional Justice Center Project
  • King County Vashon Recycling/Transfer Station Project
• For More Information
  • King County Solid Waste Division's Construction Recycling Guide
  • King County Solid Waste Division's Contractor's Guide
• Vendor Information

Introduction

Construction projects typically generate large volumes of waste material. Recycling can reduce the amount of material sent to the landfill and avoid landfill disposal costs.

Waste materials which can be recycled include used asphalt, used portland cement concrete, scrap gypsum wallboard, surplus paint, scrap lumber, landclearing debris such as stumps and branches, used pallets, scrap metals, and other materials.

Usage History and Experience

King County often includes language in contracts to encourage waste management and recycling on job-sites.  Following are specifications from two large projects, demolition of a site which now houses the Regional Justice Center and demolition/construction of the Vashon Recycling/Transfer Station.  These specifications sometimes require contractors to use the material they generate on-site as fill for the new construction. They also require detailed reporting of materials separated, salvaged and recycled.

Bid and Contract Specifications

This section includes various contract provisions by which materials were recycled and re-used in the project.

King County Regional Justice Center Project (1994)

This project involves the development of a new regional justice center, including courthouse and detention facilities. The project manager has required that materials be recycled on the project site and used in place of new material.

The project used recycled concrete aggregate from the demolition for backfill, general fill, pipe bedding and as aggregate base course for pavement construction in new construction.

The paragraphs below are excerpted from contract documents related to this project.

Section 01010 Summary of Work

 

F. Ownership and Disposal of Materials

1. The County wants to recycle as much material as possible during demolition and the demolition schedule has been planned to maximize the amount of recycling, reuse, and salvage that can be achieved during demolition.

1.04 Base Contract Work Includes:

4. Demolish building and foundations. Crush and stockpile concrete rubble and dispose of all re-bar. Do not mix asphalt with concrete in stockpile.

 

5. Remove drives, parking areas, walks and pads. Segregate different material types (concrete and asphalt), load, haul, crush, consolidate and stockpile material on site.

 

7. Backfill pits, holes and excavations with clean recycled crushed concrete. Backfill to surrounding grades.

 

8. Recycled crushed materials of differing material types are not to be mixed. Segregate concrete and asphalt stockpiles. Concrete which has been overlaid with asphalt shall be kept separate from other stockpiles.

 

Section 01595

 

1.03 Requirements:

 

A. The County requires the Contractor to recycle, reuse, and salvage as much material as possible. The demolition schedule was planned to allow for selective removal and sorting of materials.

 

B. The County requires the Contractor to submit a waste handling plan detailing how the waste streams will be separated and managed.

 

E. The Contractor is responsible for removing and reusing, recycling, or salvaging all other materials associated with the demolition of the buildings, pavement, vegetation, utilities, and any other site improvements.

 

Section 02235 Recycled Crushed Materials

 

Part 1-GENERAL

 

A. Concrete including concrete and cement shall be crushed on site. Crushed concrete shall be stockpiled separately on-site. Crushed concrete shall be used as backfill as specified in Section 02200, Earthwork.

 

B. Asphalt and Concrete Asphalt mixtures shall be crushed on site. No asphalt or combination of asphalt products shall be used as fill by the Demolition Contractor.

 

C. Crushed asphalt shall not be mixed with crushed concrete.

1.02 Description of Work

 

This section pertains to work involving recycled crushed concrete, crushed asphalt, and crushed concrete/asphalt materials produced on site during demolition operations. Potential sources of recycled crushed materials on site include (but are not limited to) existing foundations, floor slabs, reinforced concrete walls, and pavements. Mixed crushed recycled concrete/asphalt may occur as a result of demolishing concrete slab areas overlain by asphalt surfacing. All reinforcing steel shall be removed from concrete elements prior to crushing, and exported from the site.

Recycled crushed concrete may be used on site as backfill in the parking garage over excavation zone identified on the project plans, or as general backfill to fill depressions produced during demolition or within low areas. Recycled crushed concrete will also be stockpiled on site for use during future site work, as backfill in future footing over excavation zones, as general fill, pipe-bedding or backfill, and as aggregate base course for pavement construction. Recycled crushed asphalt or mixed asphalt/concrete will be stockpiled on site for use during future site work, as general fill or aggregate base beneath paved areas. Brick, masonry, and CMU elements will be demolished as part of this contract. These materials will not be reused on site, but should be demolished and exported from the site.

 

1.03 Description of Site Conditions:

 

A. Reuse, recycle and salvage as much material as possible.

 

B. Stockpile the various types of crushed recycled materials in separate, secure areas as directed by the County.

 

C. Do not mix recycled materials with soil, and do not mix crushed recycled concrete with asphalt.

 

 

Part 2 - PRODUCTS

2.01 Crushed Recycled Concrete:

 

A. Crushed recycled concrete materials shall conform to the following gradation specification:

B. Recycled concrete materials used or stockpiled on site shall be uniform in quality and free from wood, steel, roots, bark or other extraneous material. In addition, the recycled concrete materials shall meet the following requirements:

Los Angeles Abrasion, 500 rev. -- 35%max Sand Equivalent -- 30 min

2.02 Crushed Recycled Asphalt Pavement:

 

A. Existing asphalt concrete pavement on site shall be pulverized by a method that limits damage or dislodging of the material below the pavement. The pulverized material shall conform to the following gradation:

B. Acceptance of the gradation will be based on visual inspection by Hong West, King County's Representative.

2.03 Mixed Crushed Concrete/Asphalt

A. Any mixed crushed concrete/asphalt shall conform to the gradation specified above in Section 2.02.

Part 3 - EXECUTION

 

A. The Contractor shall crush, haul and stockpile the crushed Materials to a stockpile area on site designated by King County, and crushed recycled materials shall not be placed higher than Elevation 33 within the parking garage excavation, as shown on the project plans.

B. Where used as backfill in the parking garage over excavation zones, the recycled concrete shall be placed on properly-prepared subgrade. Where very soft, wet subgrade conditions are encountered, use a geotextile separator between subgrade soils and the recycled concrete. Evaluation of conditions requiring use of a geotextile separator, and monitoring of geotextile placement, shall be performed in the field by Hong West, King County's Representative.

C. Where placed as compacted fill, recycled concrete materials shall be moisture conditioned to within 3 percent of the optimum moisture content, placed in horizontal lifts less than 8 inches in loose thickness, and compacted to at least 95 percent maximum dry density, determined using ASTM D 1557. Where used as general backfill in areas to be reloaded, the recycled concrete shall be compacted to at least 90 percent maximum dry density, and using the same criteria.

PART 4 - QUALITY CONTROL

 

A. The Contractor is responsible for the quality of the work and for complying with the specifications. Testing will be conducted by Hong West and King County.

 

B. The following laboratory tests will be performed on the recycled concrete:

 

L.A. Abrasion Testing for determination of aggregate durability, using ASTM C 131.
Sand Equivalent Testing, using ASTM C 2419.
Sieve analysis for acceptance of aggregate gradation, using ASTM D 422.

C. Other tests may be performed as necessary based on field conditions, to verify the suitability of the crushed recycled materials for the intended purpose.

 

PART 5 - MEASUREMENT AND PAYMENT

 

A. Crushing, placement, and stockpiling of crushed recycled materials shall be measured by lump sum as part of the base bid.

 

B. Crushed recycled materials that do no meet gradation or other criteria specified herein shall be removed from the site and disposed of at the Contractor's expense.

 

C. Unauthorized excavation consists of removal of materials beyond indicated subgrade elevations or dimensions, or beyond that level required for normal clearing and grubbing operations or removal of structural elements, without specific direction of King County. Unauthorized excavations within footing over excavation zones shall be backfilled in accordance with these specifications, at the Contractor's expense. Any unauthorized excavations in other areas of the site shall be backfilled as directed by Hong West.

 

D. Any additional testing required due to recycled crushed materials failing laboratory or field density test specifications shall be at the Contractor's expense. In addition, testing related to backfilling of unauthorized excavations shall be at the Contractor's expense.

 

E. No payment will be made for materials which have become mixed with other material or misplaced by the Contractor's action, or lack of action. Crushed recycled material which is contaminated by the Contractor by spills or mixing with other site soils, or by any other means, shall be tested, removed, and disposed of by the Contractor at the Contractor's expense.

 

2.03 BACKFILLING (Supplemental)

 

G. 5. The Contractor shall backfill the portion of the excavation above the lean concrete using recycled crushed concrete and/or structural fill, in accordance with applicable sections of the

Specifications.

Summary:

The Regional Justice Center project team was able to recycle ninety-five percent of the demolition-debris generated during the demolition phase of the project and saved almost $250,000. Most of the concrete and asphalt, 31,840 tons, was crushed and used as fill-material on the project site. A local recycler accepted 1,518 tons of concrete rubble, 791 tons of steel and 918 tons of waste-wood, ; and 750 tons of lumber was salvaged. Only 1706 tons of the material generated was not able to be recycled.

King County Vashon Recycling/Transfer Station (1998)

Construction Waste Management

PART 1 GENERAL
1.01 DESCRIPTION

A. The Owner desires that this Project shall generate the least amount of waste possible and that processes that ensure the generation of as little waste as possible due to error, poor planning, breakage, mishandling, contamination, or other factors shall be employed.

B. Of the inevitable waste that is generated, as many of the waste materials as economically feasible shall be reused, salvaged, or recycled.

C. With these goals, the Contractor shall develop, for the Engineer's review, a Waste Management Plan for the Project.

D. Contractor shall be responsible for all costs associated with Contractor's disposal at the Vashon Island Landfill. The Contractor shall weigh in and out of the scales and pay the appropriate disposal fee.

1.2 WASTE MANAGEMENT PLAN

A. Draft Waste Management Plan: Within fourteen working days after effective date or Notice to Proceed, or prior to any waste removal, whichever occurs sooner, the Contractor shall submit 3 copies of the Draft Waste Management Plan to the Engineer.

B. The following resources are available from the King County Solid Waste Division Construction, Demolition and Landclearing (CDL) Program. These materials may be used for development of the Waste Management Plan. In addition, the Contractor may request specific technical assistance from the CDL program in the development of the Waste Management Plan, for on-site contractor and subcontractor training, and on-site inspections.

C. Final Waste Management Plan: Once the Owner has determined which of the recycling options addressed in the above draft Waste Management Plan are acceptable, the Contractor shall submit, within 14 working days, a Final Waste Management Plan.

The Final Waste Management Plan shall contain the following:

1. Analysis of the proposed jobsite waste to be generated, including types and quantities.

2. A list of all materials from the Project that will be separated for reuse, salvage, or recycling.

1.03 MANAGEMENT PLAN IMPLEMENTATION

A. Manager: The Contractor shall designate an on-site party (or parties) responsible for instruction workers and overseeing and documenting results of the Waste Management Plan for the Project. The Owner will provide staff to assist in this training and to make periodic site visits.

B. Distribution: The Contractor shall distribute copies of the Waste Management Plan to the Job-Site Supervisor, each Subcontractor the Owner and the Engineer.

C. The Contractor shall provide on-site instruction of appropriate separation, handling separation, handling, and recycling, salvage, reuse and return methods to be used by all parties at the appropriate stages of the Project.

D. Separation Facilities: The Contractor shall lay out and label a specific area to facilitate separation of materials for potential recycling, salvage, reuse and return. Recycling and waste bin areas are to be kept clean and clearly marked in order to avoid contamination of materials.

E. Hazardous wastes: Hazardous wastes shall be separated, stored, and disposed of according to local regulations.

F. Submission of Progress Reports: The Contractor shall submit with each Progress Report a summary of Waste generated at the Project. The Summary shall be submitted on a form acceptable to the Owner and shall contain the following information.

For More Information

Further information may be available through the following main menu selections:

 

King County Recycled Content Supply Contracts
Resources for Buyers
Standard Paragraphs for Contracts

Vendor Information

In King County, a construction, demolition, and landclearing debris (CDL), materials management resource guide is available. This guide lists vendors who accept material from scrap metal to used pallets. The guide also offers hints for recycling and buying recycled materials.

King County Solid Waste Division's Contractor's Guide

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