Construction Materials: Geology, Planning & the Environment
Stephen Davey, from Klipberg Consulting, will present the Department of Geological Sciences seminar with a talk entitled, "Construction Materials: Geology, Planning & the Environment".
Construction materials are an essential component in the economic revival of South Africa.
Every construction and development project in South Africa requires basic construction materials such as building sand, stone aggregate, cement and bricks.
Municipalities depend on construction materials in order to develop infrastructure and improve the living conditions for people, yet most Spatial Development Frameworks (SDF) hardly include anything about the sources of suitable construction materials.
Perhaps, because it is assumed that these basic construction materials are readily available everywhere, very little attention is paid to identifying the sources of suitable construction materials in Strategic Environmental Assessments (SEA) and Environmental Impact Assessments (EIA).
Suitable construction materials are not distributed evenly over South Africa. The underlying geology determines the location of mineral resources including construction materials.
Construction and development is not only required in towns and cities there are many projects situated in the rural areas of South Africa e.g. renewable energy projects, the Square Kilometre Array (SKA) and the provision of basic services in numerous smaller towns and villages.
“Concrete is the world’s most consumed resource after water”. Concrete is used in all infrastructure projects that are essential to communities’ economic and social development. The concrete base for a single wind turbine on a Wind Farm can use up to 60 truckloads of concrete. Concrete is made of cement, sand, stone aggregate and water.
This paper focuses on the sand and stone aggregate that needs to be obtained from quarries or borrow pits.
There are SANS specifications for concrete sand in terms of grain size, grading, clay content etc. and so not all sand is suitable for making concrete.
For example, much of the Karoo is underlain by shale or mudstone, and these are fine-grained rocks that do not weather into sand that can be used for making concrete. So suitable concrete sand, for the construction of the Square Kilometre Area (SKA) and for renewable energy projects may need to be transported for long distances to the construction sites.
More attention is required in forward planning instruments such as SDFs and SEAs as well as in project level EIAs to the responsible sourcing of construction materials
Whereas good quality biodiversity information is available on line (e.g. CBA maps) from the South African National Biodiversity Institute (SANBI), geological maps and information is not so easily available on line from the Council for Geoscience (CGS).
The Council for Geoscience is a statutory council (like the CSIR) responsible for providing information related to geology and mineral resources (including construction materials).
Town planners and environmental consultants should consult with the Council for Geoscience (www.geoscience.org.za) in order to obtain the latest and most relevant geological information applicable to their area so that the most suitable and environmentally responsible sites can be identified as potential sources for the required construction materials.