Loose Aggregates
(4 Products)Loose Aggregates form a core group of granular construction materials used for sub-base formation, drainage systems, concrete production, and surface finishing. This range includes sand, gravel, crushed stone, and recycled aggregate, providing essential mass, stability, and permeability across civil engineering and building applications.
Understanding Loose Aggregates
Loose aggregates refer to free-draining, unbound mineral materials used across multiple phases of construction. They form the foundational and load-bearing layers beneath pavements, roads, and slabs, distributing weight and enhancing stability.
These mineral-based granular materials are used in construction for forming sub-bases, concrete mixes, and surface layers. They serve as a fundamental component of the built environment, combining with binders such as cement or bitumen to form stable and durable composite materials.
Aggregate performance depends on grading, particle shape, and mineral composition, influencing strength, compaction, and permeability. Aggregates are classified by size into coarse and fine fractions.
Fine aggregates, typically sand, fill voids and improve mix cohesion, while coarse aggregates, including gravel or crushed rock, contribute to structural integrity. Their geological origin, whether natural or processed, affects physical and chemical behaviour in construction environments.
Quality control of loose aggregates follows strict testing for particle size distribution, fines content, and resistance to degradation. Suitability varies with application, requiring specific blends for concrete, asphalt, or sub-base layers to meet engineering design requirements.
Natural aggregates originate from riverbeds, quarries, or pits, whereas recycled and secondary aggregates are derived from processed demolition waste or industrial by-products. Selection depends on application-specific requirements for compaction, permeability, or visual appearance. In drainage and landscaping, washed aggregates are preferred for their cleanliness and consistent grading.
Aggregate classification is generally based on size, with fine aggregates such as sand used for mortar and plaster, and coarse aggregates like gravel and crushed stone employed in structural and load-bearing applications.
Material Range
- Sand: Fine aggregate produced from natural deposits or crushed rock, used in mortar, render, and concrete.
- Gravel: Rounded or sub-rounded coarse aggregate sourced from river beds or pits, suited to drainage and decorative use.
- Crushed Stone: Mechanically fractured rock offering angular particles for high interlock strength in road bases and concrete.
- Ballast: Coarse blend of stone and sand used for track beds and foundations requiring drainage and stability.
- Recycled Aggregates: Derived from crushed concrete or asphalt, providing a sustainable alternative to quarried materials.
Key Features
- Grading: Controlled particle distribution ensuring consistent compaction and load-bearing performance.
- Durability: Resistance to crushing, weathering, and chemical attack under varying environmental conditions.
- Permeability: Variable drainage capacity depending on particle size and composition.
- Compatibility: Suitability for use with cementitious or bituminous binders in structural mixes.
- Sustainability: Recycled and secondary aggregates reduce quarrying demand and embodied carbon.
Typical Applications
- Concrete production: Coarse and fine aggregates form the structural matrix in reinforced and unreinforced concrete.
- Road and pavement bases: Crushed rock and graded blends provide load distribution and sub-base stability.
- Drainage systems: Open-graded gravels facilitate water movement in soakaways and filter beds.
- Landscaping and surfacing: Decorative gravels and chippings used for paths, driveways, and planting areas.
- Railway track ballast: Coarse aggregates maintain track alignment and provide rapid drainage.
Specification & Standards
- BS EN 12620: Specifies aggregate requirements for concrete, including grading, impurities, and strength characteristics.
- BS EN 13043: Defines properties and grading for aggregates used in asphalt and road construction.
- BS EN 13242: Covers aggregates for unbound and hydraulically bound mixtures used in civil engineering works.
- BS EN 933: Describes testing methods for particle size distribution and shape classification.
- BS EN 1097: Establishes testing for mechanical and physical properties such as density, strength, and resistance to fragmentation.
- BS EN 16236: Sets out quality management requirements for aggregate sourcing, cleanliness, and grading verification.
Related Materials and Construction Uses
Loose aggregates combine with cement, bitumen, and geotextiles in structural, civil, and geotechnical systems. They provide the foundation for concrete, asphalt, and precast components, forming critical base and binder layers.
Aggregates interface with drainage pipes, paving slabs, and structural fills, influencing the performance of associated materials including mortar, screed, and concrete blocks.
Frequently Asked Loose Aggregates Questions
What Is The Difference Between Primary And Recycled Aggregates?
Primary aggregates are sourced from quarries and include materials like limestone and granite. Recycled aggregates are produced by processing construction waste, meeting standards such as BS EN 12620 for concrete aggregates.
What Standards Govern The Quality Of Loose Aggregates?
Loose aggregates must comply with BS EN 12620 for concrete, BS EN 13242 for unbound and hydraulically bound mixtures, and BS EN 13139 for mortar. These standards specify grading, cleanliness, and particle shape.
How Is Aggregate Grading Determined?
Grading refers to particle size distribution, tested according to BS EN 933-1. Proper grading ensures stability, workability, and compaction depending on the intended use, such as drainage or structural fill.
What Are Typical Uses For Loose Aggregates In Construction?
They are used for concrete production, road bases, drainage layers, pipe bedding, and general fill. Specific aggregate sizes are selected based on performance requirements and load-bearing capacity.
Can Loose Aggregates Be Used For Permeable Surfaces?
Yes. Washed gravels and coarse aggregates are commonly used in permeable paving and sustainable drainage systems (SuDS) to promote infiltration and reduce surface water runoff.
How Should Loose Aggregates Be Stored On Site?
Aggregates should be stored on firm, level ground, separated by type, and protected from contamination and excessive moisture to maintain grading and performance consistency.
