Construction_ Renovation_ Demolition - Environmental by dfsdf224s

VIEWS: 7 PAGES: 6

									Environmental                                           Chapter 5 – Guidelines For Purchasing Specific Types of Products

           Purchasing Guide

5.8 Construction, Renovation, Demolition

5.8.1        Construction and Demolition
             Waste
An Overview
Moving, renovating, and demolishing facilities can generate significant waste. Construction and
demolition waste accounts for up to 25% of the waste stream. Reorganizations in offices and facilities
both add to the challenge and open new opportunities to apply sound environmental practices. These
practices can lead to improved energy efficiency and workplace and public facility standards.
For the “renovation component” of any required work you may also refer to section 5.1.1 through 5.1.8
to consider replacement materials.
Potential Environmental Impacts
     n   Poor waste management practices throughout any construction, renovation or demolition project
         will add to disposal volumes and their impacts on the environment.
Things to Consider If You Write Your Own Specifications
Contractors should be required to submit a Waste Management Plan with their quotations. The plan
should include:
     n   Procedures for educating workers and subcontractors in order to ensure adherence to the Waste
         Management Plan
     n   Methods for reducing waste such as ordering material only as required, using up excess material on
         site where possible, or prefabricating sections off site
     n   The percentage of recycled content in construction materials
     n   Methods and techniques for collecting, separating, and recycling waste materials and packaging,
         including a list of materials to be recycled and percentage expected to be recycled or sent to
         landfills
     n   Provisions for dealing with hazardous waste, including procedures for handling, clean-up and
         disposal
     n   A list of carriers and disposal destinations for each material to be disposed of or recycled. The list
         should be provided initially or at least before the final payment is made. This will ensure that all
         materials are being recycled and waste is legally disposed of
     n   Alternative options for recovering higher percentages of materials and related costs
     n   The cost associated with the recovery of the material and the anticipated revenues from the sale of
         such material.
Specifications from Other Agencies and Seals of Approval
Sample specifications from other agencies are outlined in the pages following immediately and in
Appendix C - GVRD Project Waste Management Master Specification.
Case Study: Energy Efficient City Hall
                                           Thanks to innovative design and attention to environmental
                                           details, the new Richmond City Hall will be 25 per cent more
                                           energy efficient than a standard office building. From energy
                                           efficient boilers to a system that automatically shuts off air
                                           conditioning when windows are opened, City Hall is a model for
                                           energy conservation. In fact, the City has been awarded federal
                                           funds in recognition of the building’s energy efficiencies.

 Richmond City Hall


48       City of Richmond                                                                                  February 2001
                                                                                                                 287998
Chapter 5 – Guidelines For Purchasing Specific Types of Products              Environmental
                                                                                       Purchasing Guide

  Case Study: Construction waste                                   An example from King County Washington
  management at Richmond City                                      highlights some typical specifications:
  Hall.
  When City of Richmond staff prepared the
                                                                    King County Regional Justice Center
  construction documents for the new City                           Project Overview
  Hall, they began a process that would not
  only see significant volumes of waste                             This project involved the development of
  recycled but would result in scores of                            a new regional justice center, including
  contractors being introduced to value of                          courthouse and detention facilities. The
  construction waste recycling. Richmond                            project manager required that materials be
  used the GVRD Project Waste                                       recycled on the project site and used in
  Management Master Specifications to set                           place of new material.
  out standards for recycling and waste
  management on the construction site.
                                                                    The project used recycled concrete
  During construction, wood waste, scrap
                                                                    aggregate from the demolition for
  metal, drywall and cardboard were
                                                                    backfill, general fill, pipe bedding and as
  targeted for recycling. Weekly site
                                                                    aggregate base course for pavement
  meetings were used to educate and inform
  contractors about the recycling program.                          construction in new construction.
  A site safety officer wass responsible for
  talking to contractors, keeping recycling                         The Regional Justice Center project team
  bins clear of contamination, and ensuring                         was able to recycle ninety-five percent of
  the program ran smoothly.                                         the demolition-debris generated during
  Urban Wood Waste Recyclers of south                               the demolition phase of the project and
  Vancouver accepted and sorted the co-                             saved almost $250,000. Most of the
  mingled bins of materials. Wood waste                             concrete and asphalt, 31,840 tons, was
  was processed into hogfuel and taken to                           crushed and used as fill-material on the
  Canadian Forest Products where it was                             project site. A local recycler accepted
  used to make value-added products such                            1,518 tons of concrete rubble, 791 tons of
  as hardboard paneling and hydro-seeding                           steel and 918 tons of waste-wood, ; and
  mulch. Cardboard went to Crown                                    750 tons of lumber was salvaged. Only
  Packaging for recycling into new                                  1706 tons of the material generated was
  cardboard products. Scrap metal was sent                          not able to be recycled.
  to Richmond Steel, ABC Recycling and
  others for recycling.
                                                                    The paragraphs below are edited from
                             Calculations suggest                   contract documents related to this project.
                             that 81% of total
                             waste material was
                             diverted to recycling.
                             Source: GVRD
                             Construction and
                             Demolition
                             Recycling
                             Document.

   City Hall -
   New Construction




February 2001                                                                           City of Richmond      49
287998
Environmental                                     Chapter 5 – Guidelines For Purchasing Specific Types of Products

           Purchasing Guide

Summary of Work                                             n   The County requires the Contractor
                                                                to submit a waste handling plan
Ownership and Disposal of Materials                             detailing how the waste streams will
                                                                be separated and managed.
                                                            n   The Contractor is responsible for
     n   The County wants to recycle as much                    removing and reusing, recycling, or
         material as possible during                            salvaging all other materials
         demolition and the demolition                          associated with the demolition of the
         schedule has been planned to                           buildings, pavement, vegetation,
         maximize the amount of recycling,                      utilities, and any other site
         reuse, and salvage that can be                         improvements.
         achieved during demolition.
                                                         Recycled Crushed Materials
Base Contract Work
                                                         General
     n   Demolish building and foundations.
         Crush and stockpile concrete rubble
         and dispose of all re-bar.                         n   Concrete including concrete and
     n   Do not mix asphalt with concrete in                    cement shall be crushed on site.
         stockpile.                                             Crushed concrete shall be stockpiled
     n   Remove drives, parking areas, walks                    separately on-site. Crushed concrete
         and pads. Segregate different                          shall be used as backfill as specified
         material types (concrete and asphalt),                 in Section 02200, Earthwork.
         load, haul, crush, consolidate and                 n   Asphalt and Concrete Asphalt
         stockpile material on site.                            mixtures shall be crushed on site. No
     n   Backfill pits, holes and excavations                   asphalt or combination of asphalt
         with clean recycled crushed concrete.                  products shall be used as fill by the
         Backfill to surrounding grades.                        Demolition Contractor.
     n    Recycled crushed materials of                     n   Crushed asphalt shall not be mixed
         differing material types are not to be                 with crushed concrete.
         mixed. Segregate concrete and
         asphalt stockpiles. Concrete which              Description of Work
         has been overlaid with asphalt shall
         be kept separate from other                     This section pertains to work involving
         stockpiles.                                     recycled crushed concrete, crushed
                                                         asphalt, and crushed concrete/asphalt
Requirements                                             materials produced on site during
                                                         demolition operations. Potential sources
                                                         of recycled crushed materials on site
     n   The County requires the Contractor              include (but are not limited to) existing
         to recycle, reuse, and salvage as               foundations, floor slabs, reinforced
         much material as possible. The                  concrete walls, and pavements. Mixed
         demolition schedule was planned to              crushed recycled concrete/asphalt may
         allow for selective removal and                 occur as a result of demolishing concrete
         sorting of materials.                           slab areas overlain by asphalt surfacing.
                                                         All reinforcing steel shall be removed
                                                         from concrete elements prior to crushing,
                                                         and exported from the site.

50       City of Richmond                                                                            February 2001
                                                                                                           287998
Chapter 5 – Guidelines For Purchasing Specific Types of Products             Environmental
                                                                                     Purchasing Guide

 Recycled crushed concrete may be used                                     Sieve Size    Percent Passing by
 on site as backfill in the parking garage                                 U.S. Standard Dry Weight
 over excavation zone identified on the
                                                                           1 – ½ inch      100
 project plans, or as general backfill to fill
                                                                           ¾ inch          40-75
 depressions produced during demolition
                                                                           ¼ inch          25-50
 or within low areas. Recycled crushed
                                                                           No. 40          5-20
 concrete will also be stockpiled on site for
                                                                           No. 200         10 max.
 use during future site work, as backfill in
 future footing over excavation zones, as
 general fill, pipe-bedding or backfill, and                               Recycled concrete materials used
 as aggregate base course for pavement                                     or stockpiled on site shall be
 construction. Recycled crushed asphalt or                                 uniform in quality and free from
 mixed asphalt/concrete will be stockpiled                                 wood, steel, roots, bark or other
 on site for use during future site work, as                               extraneous material. In addition,
 general fill or aggregate base beneath                                    the recycled concrete materials
 paved areas. Brick, masonry, and CMU                                      shall meet the following
 elements will be demolished as part of                                    requirements:
 this contract. These materials will not be
 reused on site, but should be demolished                                  Los Angeles Abrasion, 500 rev.
 and exported from the site.                                               — 35% max Sand Equivalent —
                                                                           30 min.
 Description of Site Conditions
                                                                     n   Crushed Recycled Asphalt Pavement
    n   Reuse, recycle and salvage as much
        material as possible.                                              Existing asphalt concrete
    n   Stockpile the various types of                                     pavement on site shall be
        crushed recycled materials in                                      pulverized by a method that limits
        separate, secure areas as directed by                              damage or dislodging of the
        the County.                                                        material below the pavement. The
    n   Do not mix recycled materials with                                 pulverized material shall conform
        soil, and do not mix crushed recycled                              to the following gradation:
        concrete with asphalt.

                                                                           Sieve Size    Percent Passing by
 Products                                                                  U.S. Standard Dry Weight
                                                                           1 – ½ inch      100
    n   Crushed Recycled Concrete                                          ¾ inch          40 min.

            Crushed recycled concrete                                      Acceptance of the gradation will
            materials shall conform to the                                 be based on visual inspection by
            following gradation specification:                             the County's Representative.

                                                                     n   Mixed Crushed Concrete/Asphalt

                                                                   Any mixed crushed concrete/asphalt shall
                                                                   conform to the gradation specified above.


February 2001                                                                           City of Richmond   51
287998
Environmental                                       Chapter 5 – Guidelines For Purchasing Specific Types of Products

           Purchasing Guide

Execution                                                             L.A. Abrasion Testing for
                                                                      determination of aggregate
     n   The Contractor shall crush, haul and                         durability, using ASTM C 131.
         stockpile the crushed Materials to a                         Sand Equivalent Testing, using
         stockpile area on site designated by                         ASTM C 2419.
         King County, and crushed recycled                            Sieve analysis for acceptance of
         materials shall not be placed higher                         aggregate gradation, using ASTM
         than Elevation 33 within the parking                         D 422.
         garage excavation, as shown on the
         project plans.                                    Other tests may be performed as
     n   Where used as backfill in the parking             necessary based on field conditions, to
         garage over excavation zones, the                 verify the suitability of the crushed
         recycled concrete shall be placed on              recycled materials for the intended
         properly prepared subgrade. Where                 purpose.
         very soft, wet subgrade conditions
         are encountered, use a geotextile
                                                           Measurement and Payment
         separator between subgrade soils and
         the recycled concrete. Evaluation of
         conditions requiring use of a                        n   Crushing, placement, and stockpiling
         geotextile separator, and monitoring                     of crushed recycled materials shall
         of geotextile placement, shall be                        be measured by lump sum as part of
         performed in the field by County's                       the base bid.
         Representative.                                      n   Crushed recycled materials that do
     n   Where placed as compacted fill,                          no meet gradation or other criteria
         recycled concrete materials shall be                     specified herein shall be removed
         moisture conditioned to within 3                         from the site and disposed of at the
         percent of the optimum moisture                          Contractor's expense.
         content, placed in horizontal lifts less             n   Unauthorized excavation consists of
         than 8 inches in loose thickness, and                    removal of materials beyond
         compacted to at least 95 percent                         indicated subgrade elevations or
         maximum dry density, determined                          dimensions, or beyond that level
         using ASTM D 1557. Where used as                         required for normal clearing and
         general backfill in areas to be                          grubbing operations or removal of
         reloaded, the recycled concrete shall                    structural elements, without specific
         be compacted to at least 90 percent                      direction of King County.
         maximum dry density, and using the                       Unauthorized excavations within
         same criteria.                                           footing over excavation zones shall
                                                                  be backfilled in accordance with
                                                                  these specifications, at the
Quality Control
                                                                  Contractor's expense. Any
                                                                  unauthorized excavations in other
     n   The Contractor is responsible for the                    areas of the site shall be backfilled as
         quality of the work and for                              directed by the County
         complying with the specifications.                       representative.
         Testing will be conducted by County.
     n   The following laboratory tests will
         be performed on the recycled
         concrete:


52       City of Richmond                                                                              February 2001
                                                                                                             287998
Chapter 5 – Guidelines For Purchasing Specific Types of Products            Environmental
                                                                                     Purchasing Guide

    n   Any additional testing required due                        Case Study: Deconstruction, not
        to recycled crushed materials failing                      demolition.
        laboratory or field density test
        specifications shall be at the                             When the University of British
        Contractor's expense. In addition,                         Columbia decided to raze the wood-
        testing related to backfilling of                          framed “Pan-Hellenic House” to make
        unauthorized excavations shall be at                       way for a new building, project
        the Contractor's expense.                                  specifications stated that the building
    n   No payment will be made for                                was to be deconstructed, not
        materials which have become mixed                          demolished. Bidders were asked to
        with other material or misplaced by                        submit material reuse and recycling
        the Contractor's action, or lack of                        targets along with their pricing.
        action. Crushed recycled material                          The successful bidder, Litchfield & Co.
        which is contaminated by the                               Ltd., deconstructed the building using
        Contractor by spills or mixing with                        primarily manual labour. The interior
        other site soils, or by any other                          was stripped of salvageable items (e.g.
        means, shall be tested, removed, and                       cedar siding, dimensional lumber,
        disposed of by the Contractor at the                       electrical and bathroom fixtures) and
        Contractor's expense.                                      recyclable materials (e.g. drywall, wood
                                                                   waste, scrap metal and stucco). In total
 Supplemental Backfilling                                          94% of demolition material was
                                                                   salvaged or recycled and only 6%
                                                                   landfilled.
    n   The Contractor shall backfill the
        portion of the excavation above the                        Of the total recovered materials, 17 %
        lean concrete using recycled crushed                       was salvaged and 77% was taken to
        concrete and/or structural fill, in                        local scrap metal, concrete, wood and
        accordance with applicable sections                        drywall recycling facilities. Glulam
        of the specifications.                                     beams and tongue-and-groove decking
                                                                   salvaged from the “Pan-Hellenic House”
                                                                   were used on site in the construction of
See also the GVRD Project Waste                                    the new Liu Centre for the Study of
Management Master Specification,                                   Global Issues.
Appendix C.
                                                                   Source: Demolition and Salvage Facts,
                                                                   GVRD.




                                                                   Pan-Hellenic House at UBC




February 2001                                                                         City of Richmond       53
287998

								
To top