Published on:

27 June 2016

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Types of use:  concrete, random rubble masonry, aggregate base
concrete (ABC), road base, manufacturing sand, asphalt

Environmental Impacts:

Extraction

Erosion of channel bed and banks, increase in channel slope, and change
in channel morphology. These impacts may cause:

  1. the undercutting and collapse of river banks
  2. the loss of adjacent land and/or structures
  3. upstream erosion
  4. downstream erosion
  5. downstream changes in patterns of deposition
  6. destruction of riverine habitats

Transport

Transport using large trucks affects rural roads and may cause noise and
air pollution.

Production/Treatment

Often used after crushing into uniform sizes or fines (sand). Crushing plants cause noise, air pollution, silting of water bodies/ wetlands etc.

Toxicity

None

Environmental Benefits: 

None

Potential Material Alternatives: 

crushed rock, crushed rubble (debris)

Environmental Better Practices:

Design and Planning

  • Plan and design construction to minimize waste
  • Use alternatives to concrete/mortar (e.g., stabilized earth walls)
  • Use premixed concrete instead of in-situ mixing
  • Use prefabricated concrete items

Storage

  • Locate stockpiles to provide safe access for withdrawing material.

Use 

  • Adhere to the building specifications mixing mortar and concrete and
    Overuse of material will not add any additional strength and will
    only cause waste.
  • Mix in small adequate batches to minimize waste. Don’t mix up more fresh concrete/mortar than you will use in a two-hour period.

Disposal 

Never dispose wash out cement, sand, cement mortar or concrete into
environment. They can be:

  1. reused onsite/offsite for construction purposes (e.g. filling)
  2. safely transported to a construction material recycling facility, or
  3. safely transported to a sanitary landfill

Key Resources for River Gravel/Boulders:

Environmental, Health, and Safety Guidelines for Construction Materials Extraction – International Finance Corporation (IFC)

Sand, Rarer than One Thinks – Global Environmental Alert Service, UNEP

Construction Site Best Management Practice (BMP) – California Department of Transport

Standards for Material Handling, Storage and Disposal – US Bureau of Reclamation

Recycled Aggregates – Portland Cement Association (PCA)

Guidelines for Selective Demolition and On Site Sorting – Civil Engineering and Development Department (Hong Kong)