Gravel v hardcore v aggregates
Gravel, hardcore and aggregates are similar types of materials that are used in construction, and as such, the terms are often confused or used interchangeably.
Gravel is a loose aggregation of small, variously sized fragments of rock which can either be naturally-formed or manufactured. Gravel can be used for the manufacture of concrete, as well as for mixing with asphalt as part of road construction. It can be used as the base layer for roads before being covered with tarmac, and is also commonly used to surface roadways.
For more information see: Gravel.
The term 'hardcore' refers to the mass of solid materials used as a make-up, formation material to raise levels, fill irregularities in excavations and create a firm and level working base onto which heavy load-bearing surfaces such as stone or concrete can be laid. Hardcore helps evenly spread imposed loads. Hardcore may be used in the formation of roads, paving, driveways, foundations, ground floor slabs, and so on. It may also be used on its own to form a temporary road surface on construction sites. Gravel can be used to make up a hardcore level.
For more information see: Hardcore.
Aggregate is a material used in construction as a means of stabilising and reinforcement, included, for example as a component of concrete and cement. It is a broad category which includes coarse-to-medium grained particulate materials such as sand, gravel, crushed stone, slag, and so on. Aggregates are also used in construction to provide drainage, fill voids, protect pipes, and to provide hard surfaces.
For more information see: Aggregate.
[edit] Find out more
[edit] Related articles on Designing Buildings Wiki
Featured articles and news
Professional practical experience for Architects in training
The long process to transform the nature of education and professional practical experience in the Architecture profession following recent reports.
A people-first approach to retrofit
Moving away from the destructive paradigm of fabric-first.
International Electrician Day, 10 June 2025
Celebrating the role of electrical engineers from André-Marie Amperè, today and for the future.
New guide for clients launched at Houses of Parliament
'There has never been a more important time for clients to step up and ...ask the right questions'
The impact of recycled slate tiles
Innovation across the decades.
EPC changes for existing buildings
Changes and their context as the new RdSAP methodology comes into use from 15 June.
Skills England publishes Sector skills needs assessments
Priority areas relating to the built environment highlighted and described in brief.
BSRIA HVAC Market Watch - May 2025 Edition
Heat Pump Market Outlook: Policy, Performance & Refrigerant Trends for 2025–2028.
Committing to EDI in construction with CIOB
Built Environment professional bodies deepen commitment to EDI with two new signatories: CIAT and CICES.
Government Grenfell progress report at a glance
Line by line recomendation overview, with links to more details.
An engaging and lively review of his professional life.
Sustainable heating for listed buildings
A problem that needs to be approached intelligently.
50th Golden anniversary ECA Edmundson apprentice award
Deadline for entries has been extended to Friday 27 June, so don't miss out!
CIAT at the London Festival of Architecture
Designing for Everyone: Breaking Barriers in Inclusive Architecture.
Mixed reactions to apprenticeship and skills reform 2025
A 'welcome shift' for some and a 'backwards step' for others.