Page 120 - ICJ Jan 2023

TECHNICAL PAPER COLLECTOR’S EDITION

Table 7. Availability of selected RSA in the UK

Material Waste Amount to Uses in concrete
generation landfill
(per annum) (per annum)
Glass Cullet 1.7 m tonnes 1.3 m tonnes Crushed glass may be used as fine aggregate, and very fine
particles may have pozzolanic properties.
Incinerator Ash 0.5 m tonnes 0.5 m tonnes Bottom ash may be developed as a lightweight aggregate. Fly
ash used as a filler material.

Used Tyres 37 million tyres banned since Used to improve thermal and sound properties of concrete,
2008 increase freeze-thaw resistance and provide impact resistance.
Oil Drill 0.3 m tonnes 0.3 m tonnes Whole or partial replacement of fine aggregate.
Cuttings

• Class B – covering most combinations of aggregates is more contentious than
natural and recycled aggregate and suitable recycled aggregates despite their inclusion in
for most ‘moderate’ exposure conditions; BS EN 12620. For one, concrete should not be seen
5
and as an alternative form of landfill, and furthermore
many of these materials will only ever be suitable
• Class C – those aggregates suitable for only
the ‘mildest’ exposure conditions. for low-value concretes. However, this is again
where the concept of appropriate use of materials
Consequently, the project provided the technical is important, and research undertaken by Dhir et al
details required to increase the use of recycled and others has shown that used appropriately in,
aggregate in concrete, and give industry greater
confidence and informing future revisions to the for example, general grade concrete, foundations
concrete standard. and low quality pavements which make up over
75% of all concrete use, there is scope for using
enormous quantities of crushed glass, municipal
SECONDARY AGGREGATES
solid waste incinerator bottom ash, oil drill cuttings
The use of some other recycled materials and used/shredded tyres (Table 7).
and industrial by-products as manufactured

The Indian Concrete Journal | November 2018 121