Slag aggregates

By-products of the steel and iron industries, slag aggregates have many valuable properties that can be used in construction, infrastructure and agriculture.


At Tarmac we have over 40 years experience of processing slag into premium and more sustainable construction materials. A direct alternative to primary aggregates, slag aggregates offer versatility and most importantly sustainable solutions to standard construction products. Steel aggregates have a high abrasion and crushing resistance for road applications: air cooled blast furnace products bond particularly well to cement and bitumous binders. They also offer significant environmental benefits such as the reuse or recycling of material and the avoidance of the need to quarry natural aggregates.

Advantages over traditional aggregates



Manufacturing

Steel aggregates have a high abrasion and crushing resistance for road applications: air cooled blast furnace products bond particularly well to cement and bitumous binders. They also offer significant environmental benefits such as the reuse or recycling of material and the avoidance of the need to quarry natural aggregates.


Agriculture

In agriculture, slag aggregates (Ag-Slag) have been used as an agricultural liming material since the 1920's in all types of crop production and landscaping. The materials are used to maximise yields of cultivated crops and pasture, improve soil texture and neutralize high soil acidity.


Concrete

In concrete, processed steel and blast furnace slag provide a sustainable alternative to primary aggregates in the production of lightweight or dense ready-mixed concrete. Blast furnace slag can also be used to make Ground Granulated Blast-furnace Slag (GGBS) which is used as a cement replacement in concrete.


Slag aggregates
in asphalt


An ideal aggregate for base, binder and surface course asphalt products, the inherent properties in steel slag are assessed in accordance with the requirements of the European standard EN 13043.

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Slag aggregates
in concrete


In concrete, processed steel and blast furnace slag provide a sustainable alternative to primary aggregates in the production of lightweight or dense ready-mixed concrete.

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Slag aggregates
in agriculture


High quality, calcium rich aggregates. Tarmac Ag Slag provides essential nutrients to soils in a slow release form.

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Why use slag aggregates?


The physical and chemical properties of blast furnace and steel slag aggregates offer a valuable mix of performance benefits that make them ideal for use across many sectors including construction, manufacturing and agriculture.


  • Durable and strong

  • Lower specific gravity and greater surface area than most primary aggregates

  • Highly resistant to weathering action such as freeze

  • Mildly alkaline (pH-value 8-10)

  • Reduced shipping and handling costs for precast units

  • High resistance to sulphate attack and alkali-silica reaction

  • Superior thermal properties to primary aggregates

  • Higher levels of fire resistance in masonry

  • Superior sound absorption

  • No corrosion risk to steel in pilings or to steel embedded in concrete made with blast furnace slag cement and/or aggregates

  • Reduced energy use and emissions from quarrying, processing and transportation of primary aggregates

  • Steel slag aggregates have high abrasion and skid resistance properties making them ideal for use in asphalt surface course materials

SteelMac proprietary asphalts

A proprietary asphalt product range produced by Tarmac using steel slag. SteelMac takes advantage of the high durability of steel slag compared to standard aggregate products. The products combined with advanced asphalt design and bitumen technology, offer application solutions for all industrial locations.


SteelMac AC 10 – car park areas, low-medium stress areas

SteelMac AC 10 HD - high stress areas

SteelMac ULTISHIELD – fuel resistant

SteelMac 10 HT - higher speed areas requiring superior surface textures

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