- Project plans
- Project activities
- Legislation and standards
- Industry context
- Specialist wikis
Last edited 27 Dec 2020
Chert is a type of fine-grained and silica-rich sedimentary rock. It often contains microfossils and/or macrofossils, and can be found in a great variety of colours. It is often confused with flint which is a particular type of chert.
Chert occurs in geology as nodules, concretionary masses and layered deposits, and is characterised by its hardness and conchoidal fractures that create sharp edges. It was these properties that meant chert was used in early human civilisations for creating tools and weapons.
Chert is often used as an aggregate and as a material for road surfacing. It is particularly suited to road surfacing as rainwater firms and compacts it rather than making it 'muddy' like some other fill materials.
However, there can be problems when is used as an aggregate in concrete, such as the development of surface pop-outs as a result of freezing and thawing. This is due to the high porosity of weathered chert. In addition, some kinds of chert can undergo an alkali-silica reaction (ASR) when they come into contact with high-alkali cement which can lead to cracking or expansion.
 Find out more
 Related articles on Designing Buildings Wiki
Featured articles and news
Two new research reports published by APM.
50% off APM Associate membership for Designing Buildings users.
A commentary from the insurance perspective.
In brief with further links.
A definitive book on a pioneer of green architecture.
Using heritage as a catalyst for reviving historic centres.
Declaration prioritising sustainable urbanisation adopted.
Some brief words about the actuator.
After 34 years at the Institute.
To support the next generation of engineers.
CIAT reporting from the Competition and Markets Authority.
Making sustainable construction number one priority.
Interview with ECA CEO.
Many provisions came into force on June 28, 2022.
With room to expand.
Refurbishment, Energy Efficiency, Indoor air and process.
Why building acoustic considerations must be non-negotiable.
Aluminium Composite Panels (ACP) is one example.
Inventors and innovators at ICE.
Life, death and art at the Stuart court. Book review.
Real estate, place adaptation and innovation.
Review and comment on the revised draft before July 11.
Write about something you know, help us build and grow !
A blended event and triumphant return.
Mark Reynolds succeeds Andy Mitchell as Co-Chair of CLC