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Stone quarrying plays a crucial role in modern construction and everyday life, supplying essential materials like sand, gravel, and stone for building roads, homes, and infrastructure.

In this guide, we will delve into the intricacies of quarrying, including what exactly it is, quarrying processes, and the materials produced.

What is Quarrying?

Quarrying is the extraction of stone or other materials from the earth, primarily to be used for construction. This process involves removing large blocks of stone or other raw materials from the ground, which are then processed and used in various construction projects.

It’s important to note that quarrying is different from mining, although people often confuse the two. Quarrying involves the extraction of non-metallic materials, whereas mining is the extraction of minerals and metals. 

At Armstrongs, we extract materials such as sand, gravel, and various types of stone, collectively known as aggregates, which are essential for construction.

The Quarrying Process

Extraction Methods

Extraction methods in quarrying can vary significantly based on the type of stone being quarried and the intended use of the material. The most common method involves drilling and blasting to break the stone into manageable pieces.

Crushing and Screening

After extraction, the stone undergoes a process called crushing and screening. Crushing reduces large blocks of stone into smaller pieces, which are then sorted by size through screening. This process ensures that the aggregates produced meet specific size and quality requirements for various construction applications. 

Crushing and screening are essential steps in producing materials like sand, gravel, and different sizes of crushed stone, which are used in concrete, asphalt, and other building materials.

Types of Quarry Stone

Sandstone

Sandstone is a sedimentary rock composed mainly of sand-sized mineral particles or rock fragments. Its characteristic layers and variety of colours, ranging from tan to yellow and red, make it a popular choice for both construction and decorative purposes. 

Sandstone is highly durable and resistant to weathering, making it ideal for use in building facades, garden walls, and paving stones. At Armstrongs, our quarries produce high-quality sandstone that is used in various prestigious projects, such as the completion of the Sagrada Familia cathedral in Barcelona.

Granite

Granite is an igneous rock known for its hardness and durability. It is composed mainly of quartz, feldspar, and mica, which give it a distinctive appearance. Granite is widely used in construction due to its strength and aesthetic appeal.

Our unique pink granite can be found at our Shap Quarry. This stone is used in both structural and decorative applications, including building facades, monuments, and countertops. 

The high grade material is also high in demand for rock armour to build up the UK’s sea and river defences. Shap quarry recently received visitors from Balfour Beatty and Wyre Council when they came to witness the blast that would produce the stone for their latest coastal defence project as part of the Wyre Beach Management Scheme.

Gritstone

Gritstone is a type of sandstone that is popular for its strength and durability. It is typically used in construction projects requiring robust and long-lasting materials. Gritstone’s rough texture makes it suitable for non-slip surfaces, and it is often used in road construction, paving, and as a base material for buildings.

Armstrongs’ Montcliffe Quarry produces high-quality gritstone, which is processed using traditional methods of crushing and screening to meet specific project needs.

Armstrongs’ Quarries

Brinscall Quarry

Brinscall Quarry covers 40 acres near the town of Chorley and has been operational for over a hundred years. This quarry produces a highly desirable sandstone known for its quality and aesthetic appeal. 

The sandstone from Brinscall is used in various construction and decorative projects, including the ongoing building of the Sagrada Familia cathedral in Barcelona. The quarry operates using traditional methods of extraction, crushing, and screening to produce top-quality aggregate materials.

Montcliffe Quarry

Montcliffe Quarry spans 64 acres near the town of Horwich, Greater Manchester, and has been in operation for over a century. This quarry is known for its high-quality gritstone, a durable and versatile stone used in construction projects. 

The gritstone from Montcliffe is ideal for road building, paving, and as a foundation material due to its strength and resistance to wear. The quarry uses traditional methods of crushing and screening following blasting to produce aggregate materials of exceptional quality.

Pilkington Quarry 1 & 2

Pilkington Quarry, covering 53 acres near Horwich, includes both operational and non-operational sites. Pilkington Quarry 1, now exhausted, is used for inert waste disposal, while Pilkington Quarry 2 remains unmined and contains highly durable pale buff/brown gritstone.

Shap Quarry

Shap Quarry, located on a 53-acre site near the village of Shap, has been operational since 1950. It is renowned for producing Shap pink granite, a highly sought-after decorative building stone.

The quarry also yields light and dark Shap granite, each serving different purposes. Light Shap granite is primarily used as aggregate, while dark Shap granite is used architecturally, as seen in the historic Midland Hotel in Manchester. 

Waddington Fell Quarry

Waddington Fell Quarry, covering 66 acres near Clitheroe, has been operational since the 1960s. This quarry produces a variety of sandstones, known for their strength and range of colours.

The sandstone from Waddington Fell is used in numerous construction projects, including cut products such as fireplaces, lintels, and even complete houses. The quarry employs traditional methods of crushing and screening following blasting to produce high-quality aggregate materials.

Uses of Quarried Stone

Construction

Quarried stone plays a crucial role in various construction projects. It is used to produce essential building materials such as aggregates for concrete and asphalt, bricks, and dimension stones for structural and decorative purposes.

Armstrongs’ stone is renowned for its quality and durability, making it a preferred choice in construction. For example, our sandstone from Brinscall Quarry is used in the Sagrada Familia cathedral in Barcelona, showcasing its high quality and aesthetic appeal.

Decorative Applications

In addition to its structural uses, quarried stone is also widely used in decorative applications. Armstrongs’ stone is crafted into fireplaces, nameplates, and bespoke architectural features. 

Our Shap pink granite and Waddington Fell sandstone are particularly popular for their unique colours and textures, enhancing the beauty of homes and public spaces. Decorative stone from our quarries adds elegance and a natural touch to various projects.

Infrastructure

Quarried stone is essential for infrastructure projects, providing the necessary materials for road construction, railway ballast, and sea and river defences. Armstrongs’ gritstone from Montcliffe Quarry and granite from Shap Quarry are used to build robust road foundations and protect coastal areas from erosion.

These projects demonstrate the importance of durable and high-quality stone in maintaining and developing infrastructure.

Environmental Considerations

At Armstrongs, we are committed to sustainable quarrying practices to minimise our environmental impact. We implement various strategies to reduce our carbon footprint and preserve natural resources.

This includes efficient extraction methods, recycling water used in the quarrying process, and rehabilitating quarry sites after extraction is complete. Our commitment to sustainability ensures that we operate responsibly and contribute to environmental conservation.

FAQs about Stone Quarrying

What is a stone quarry?

A stone quarry is a site where natural stone is extracted from the earth. The stone is typically used for construction and decorative purposes. Quarries can produce a variety of stone materials, including sandstone, granite, and gritstone. These materials are essential for building infrastructure, homes, and various other applications.

How does a quarry work?

A quarry operates through several key steps, starting with the selection of a suitable site with abundant stone reserves. The site is then prepared by clearing vegetation and setting up infrastructure.

Extraction methods such as drilling, blasting, and cutting are used to remove the stone from the ground. The stone is then crushed, screened, and sometimes treated to meet specific requirements before being distributed for use.

What types of stone are quarried?

Various types of stone are quarried, including sandstone, granite and gritstone.

What are the uses of quarried stone?

Quarried stone has a wide range of uses. One of the primary uses is for construction, with quarried stone playing a key part in the production of concrete, asphalt, bricks, and building stones.

Quarried stone also has decorative applications, where it is used for fireplaces, nameplates, and architectural features.

Finally, you can expect to see quarried stone used in road construction, railway ballast, and sea and river defences.

What is the difference between quarrying and mining?

Quarrying and mining are both methods of extracting materials from the earth, but they differ in the types of materials extracted and the processes used.

Quarrying primarily focuses on extracting building materials such as stone, sand, and gravel, whereas mining is used to extract minerals and metals such as gold, coal, and gemstones. The tools and techniques used in quarrying are also typically different from those used in mining.

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At Armstrongs and our subsidiary AMIX Concrete, we understand the important role that concrete mix ratios play in the success of any construction project. Knowing the right mix ratios is essential to achieving the desired strength, durability, and performance of concrete.

In this guide, we will explain everything you need to know about concrete mix ratios, so you can make informed decisions when it comes to mixing concrete for your projects.

What is a Concrete Mix Ratio?

A concrete mix ratio simply refers to the proportions of the components used in creating concrete. These components typically include:

• Cement
• Sand
• Aggregate
• Water

The mix ratio determines the concrete’s strength, workability, and durability. For example, a common mix ratio is 1:2:3, which means one part cement, two parts sand, and three parts aggregate. Understanding these ratios is crucial for producing concrete that meets the specific needs of your project.

Importance of Correct Concrete Mix Ratios

Strength and Durability

The strength of concrete largely depends on the correct proportion of its components. A well-balanced mix means that the concrete can withstand the intended loads and stresses over time. 

Setting Time and Workability

The mix ratio also affects how quickly the concrete sets and how workable it is during placement. Proper ratios ensure that the concrete is easy to work with and has the right setting time, preventing premature hardening or excessive delays.

Consequences of Incorrect Mix Ratios

Incorrect mix ratios can lead to several issues, such as reduced strength, increased risk of cracking, and poor durability. For example, too much water can weaken the concrete, while too little can make it difficult to work with and compact properly.

Types of Concrete Mix Ratios

Standard Mix Ratios

Standard concrete mix ratios are predefined formulas that provide consistent results for general construction purposes. Some of the most common ratios include:

1:2:3 

This mix ratio (one part cement, two parts sand, and three parts aggregate) is widely used for general construction purposes, such as small concrete projects and non-load-bearing structures.

1:3:6

This ratio (one part cement, three parts sand, and six parts aggregate) is often used for foundations and large concrete masses where strength is a primary concern.

These standard ratios are well-suited for a variety of construction tasks and provide reliable results.

Custom Mix Ratios

Custom concrete mix ratios are tailored to meet specific project requirements. These ratios can be adjusted based on the desired properties of the concrete, such as increased strength, quicker setting time, or enhanced durability.

For example, a custom mix ratio might be designed for a high-performance concrete application requiring additional admixtures or specific aggregate types. Custom mix ratios are particularly useful for specialised construction needs, ensuring that the concrete performs optimally for the intended application.

Common Concrete Mix Ratios and Their Uses

Concrete Mix Ratio for Slab

When it comes to slabs and flooring, the ideal concrete mix ratio is typically 1:2:4 (one part cement, two parts sand, and four parts aggregate). This ratio provides a balanced combination of strength and workability, making it suitable for both residential and commercial slab construction.

It ensures a durable and smooth surface capable of withstanding various loads and environmental conditions.

Concrete Mix Ratio for Driveways

For driveways and pathways, the best concrete mix ratio is often 1:2.5:3.5 (one part cement, 2.5 parts sand, and 3.5 parts aggregate). This ratio delivers high strength and durability, essential for areas subjected to frequent vehicle traffic. It creates a robust surface that can endure heavy loads while resisting cracking and wear over time.

Concrete Mix for Foundations

Foundations require concrete mixes that provide exceptional strength and stability. A common mix ratio for foundation work is 1:3:6 (one part cement, three parts sand, and six parts aggregate). This ratio ensures that the foundation has the necessary compressive strength to support the structure above, preventing settling and structural issues.

For more demanding foundation projects, a mix ratio of 1:2:4 can be used to achieve even higher strength and durability, particularly in load-bearing applications.

Adjusting Concrete Mix Ratios for Different Weather Conditions

Weather conditions can significantly impact the performance and setting time of concrete. Adjusting the mix ratios accordingly ensures optimal results in various climates.

Hot Weather

In hot weather climates, concrete tends to set faster due to the increased temperature. To counteract this, it is essential to use a mix with a higher water content or incorporate admixtures like liquid retarders to slow down the setting process. This prevents premature hardening and ensures adequate working time.

Cold Weather

In cold weather climates, concrete sets more slowly, which can lead to potential freezing before it gains sufficient strength. Using a mix with less water and incorporating accelerators can help the concrete set faster and achieve the required strength before freezing temperatures can cause damage.

Adjusting Concrete Mix Ratios for Specific Project Requirements

Different projects may have unique requirements for concrete properties, such as higher strength or quicker setting times.

High Strength

For projects requiring high-strength concrete, such as structural components and heavy load-bearing applications, the mix ratio can be adjusted to include a higher proportion of cement. This increases the overall compressive strength of the concrete, ensuring it can withstand greater loads.

Quick Setting

For projects that require fast turnaround times, such as repairs and emergency construction, quick-setting concrete mixes are essential. These mixes often include specific admixtures like accelerators to reduce the setting time, allowing the concrete to harden rapidly and be put into service sooner.

AMIX Concrete’s Ready-Mixed Solutions

At AMIX Concrete, we offer a wide range of ready-mixed concrete to meet the diverse needs of our clients. Our mixes range from GEN1, suitable for general use, to RC50, which is used for heavy-duty applications such as motorway precast concrete. Each mix is designed to provide optimal performance for specific applications, ensuring durability and reliability.

Quality and Consistency

We pride ourselves on the quality and consistency of our concrete products. By using pure Portland cement and high-quality aggregates sourced from our own quarries, we ensure that every batch of concrete meets the highest standards. 

This commitment to quality means that you can rely on AMIX Concrete for consistent performance in all your construction projects.

Admixtures and Additives

To cater to specific project requirements, AMIX Concrete offers a range of admixtures and additives, including Rapid Setting, Fibre Enhanced, Foamed and Waterproof mixes. 

These admixtures help tailor the concrete mix to meet the specific needs of your project, enhancing its performance and durability.

Concrete Mix Ratios FAQs

What is the best concrete mix ratio?

The best concrete mix ratio depends on the specific application. A common and versatile mix is the 1:2:3 ratio, which consists of one part cement, two parts sand, and three parts aggregate. This mix provides a good balance of strength and workability for general construction purposes. 

For high-strength applications, a 1:1.5:3 ratio is often used to enhance the compressive strength of the concrete.

How much water do you mix with cement?

The amount of water mixed with cement is crucial for achieving the desired concrete consistency and strength. A general guideline is to use a water-cement ratio of 0.45 to 0.60 by weight. This means that for every 100 pounds of cement, you would use 45 to 60 pounds of water.

However, the exact amount can vary based on the specific requirements of the project and the properties of the cement and aggregate used.

Can you use too much cement in a concrete mix?

Using too much cement in a concrete mix can lead to several issues. While it may increase the initial strength, it can also make the mix less workable and more difficult to place and finish. 

Additionally, excessive cement can lead to increased shrinkage and cracking as the concrete cures. It is essential to use the right balance of cement, sand, and aggregate to achieve the desired properties without compromising the performance of the concrete.

What is the difference between cement and concrete?

Cement and concrete are often used interchangeably, but they are distinct materials. Cement is a fine powder made from limestone and other minerals, which acts as a binder when mixed with water.

Concrete, on the other hand, is a composite material made from cement, water, sand, and aggregates. Cement is one of the key components of concrete, but concrete includes additional materials to create a durable and versatile building material.

How do you make a strong concrete mix?

To make a strong concrete mix, it is essential to use the correct proportions of cement, water, sand, and aggregate. A typical high-strength mix ratio is 1:1.5:3 (one part cement, 1.5 parts sand, and three parts aggregate). Using high-quality materials and ensuring proper mixing are also crucial. 

What is the sand to cement ratio for mortar?

The sand to cement ratio for mortar typically ranges from 3:1 to 4:1, depending on the specific application and desired properties. For general-purpose mortar, a 4:1 ratio (four parts sand to one part cement) is commonly used.

For higher-strength mortar, such as for load-bearing walls, a 3:1 ratio may be more appropriate. The correct ratio ensures the mortar has adequate strength, workability, and bonding properties.

How do you ensure consistency in concrete mix?

Ensuring consistency in a concrete mix involves several key practices:

• Accurate Measuring: Use precise measurements for all components (cement, sand, aggregate, and water) to maintain the correct mix ratio.
• Thorough Mixing: Mix the concrete thoroughly to ensure even distribution of all materials.
• Quality Materials: Use high-quality and consistent materials to reduce variability in the mix.
• Regular Testing: Perform regular tests on the concrete mix to check for consistency in properties like strength, workability, and setting time.
• Adhering to Standards: Follow industry standards and guidelines for concrete mixing and quality control.

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Aggregate is granular material, such as sand, gravel and crushed stone that has a range of different uses across various industries. In this guide, we’ll explain all you need to know about aggregates including the different types and their uses.

Construction aggregates play an important role in building and infrastructure projects, offering essential support and strength to various structures. In this guide, we will explore the different types of construction aggregates, their uses, and the benefits they offer.

What is Construction Aggregate?

Construction aggregate is a broad category of coarse- to medium-grained particulate material used in construction. It includes materials such as sand, gravel, crushed stone, slag, and recycled concrete. Aggregates are used in various construction applications, from residential buildings to major infrastructure projects, providing foundational strength and stability.

Types of Construction Aggregate

Natural Aggregates

Natural aggregates are sourced from natural deposits and are commonly used in construction projects. These include:

• Sand: Fine aggregate used in concrete and mortar, providing bulk, strength, and stability.
• Gravel: Coarse aggregate typically used in concrete mixes, road construction, and drainage systems.
• Crushed Stone: Made from crushed natural rock, it is used in construction, road bases, and as a binding material.

Recycled Aggregates

Recycled aggregates are produced from recycled materials such as demolished concrete, asphalt, and other construction debris. Examples include:

• Recycled Concrete: Created by crushing old concrete and used for road base, backfill, and new concrete mixes.
• Recycled Asphalt: Made by reprocessing used asphalt and commonly used in road construction and repair.

Using recycled aggregates offers several benefits, including reducing waste sent to landfills, conserving natural resources, and often providing cost savings. They are an eco-friendly alternative to natural aggregates, contributing to sustainable construction practices.

Manufactured Aggregates

Manufactured aggregates are produced through industrial processes. Examples include:

• Slag: A byproduct of steel production, slag is used in road construction, concrete, and as a soil amendment.
• Expanded Clay: Lightweight aggregate made from heating clay, used in lightweight concrete, insulation, and hydroponics.

Manufactured aggregates are designed to meet specific engineering standards and offer unique properties, such as improved strength and durability.

Natural Aggregate at Armstrongs

Natural aggregates are valued for their strength, versatility, and availability. At Armstrongs, we provide natural aggregates from our 5 quarries across the North West and Cumbria including Shap, Brinscall, Montcliffe, Pilkington 1 & 2 and Waddington Fell. 

The Extraction Process

The first step in the process of creating natural aggregate is identifying the perfect place to blast for the required stone. Once the right place in the quarry has been found, holes are drilled to the depth that is needed, depending on the amount of aggregate required. 

The holes are then filled with explosives, which allow us to release the stone we need for making the aggregate. 

Then it’s time for the blast! Once everyone has evacuated to a safe distance, we give the all clear and an almighty rumble is sent through the quarry as the rock is blasted.

Usually, this produces large pieces of stone that would otherwise be used for projects that require cut stone, such as buildings. However, for aggregate, we collect the large pieces and bash them using an excavator with a pecker tip.

We then put the smaller broken down pieces of stone into the crusher machine, which does exactly what it says on the tin! The stone is crushed down to various sizes which is sorted into categories.

Using an excavator and a truck, the pile of smaller aggregate is then transported to the screener, which will wash and sort the piles.

The Screening And Washing Process

The screener is a large vibrating box which consists of a number of various sized screens and meshes. This will separate the different sized aggregates like a sieve until they are all separated and washed.  

These sieves will separate the different sizes of aggregates and create t piles which will vary in sizes. During this screening process, the aggregate is washed to remove any unwanted materials such as clay, silt and dirt which may be present. We do this so that there is no drying effect or impurities in the future which could lead to cracking.

The various sized aggregates can be used for different functions. At Armstrongs, we produce a range of aggregate sizes from 2mm and 10mm all the way to 75mm and the gabion sized aggregate 150mm.

What is Aggregate Used for in Construction?

Structural Uses

Aggregates help with the structural integrity of concrete and asphalt, two of the most commonly used materials in construction. In concrete production, aggregates act as a filler material that provides bulk, strength, and stability to the mix.

The combination of aggregates with cement and water creates a robust material capable of withstanding significant loads and environmental stresses. Similarly, in asphalt production, aggregates are mixed with bitumen to create a durable and flexible material suitable for road surfaces.

The importance of aggregates extends to foundation construction, where they are used to create a stable base for buildings and infrastructure. Aggregates help distribute the weight of the structure evenly and provide necessary drainage, preventing water accumulation that could undermine the foundation.

Coastal Protection

Another example of aggregates and their uses are gabion baskets, which is a large aggregate inside a metal mesh basket. These gabion baskets create a sturdy structure which is perfect for coastal management.For this, we use a 150mm sized aggregate. Gabions are used in garden purposes and also civil engineering projects as well. 

Train Track Aggregate

Have you ever noticed the stone which is laid between and around the tracks which trains run on? Large and rough aggregate is used to hold down the cross tie pieces of wood between the tracks, so that they do not separate. This also helps to absorb the vibrations from the trains themselves.

Decorative Uses

Beyond their structural and coastal applications, aggregates are also used for decorative purposes in landscaping and construction. Decorative aggregates, such as coloured stones, pebbles, and gravel, are employed to enhance the aesthetic appeal of outdoor spaces. They are commonly used in pathways, garden beds, and as ground cover to create visually pleasing and low-maintenance landscapes.

In decorative concrete, aggregates can be exposed to create unique textures and patterns. This technique, known as exposed aggregate concrete, is popular for driveways, patios, and walkways. It combines the functionality of concrete with the natural beauty of aggregates, offering both aesthetic and functional benefits.

Here’s a table to demonstrate different aggregate sizes and their example uses:

Aggregate Product	Application Example
0-2mm Sand, dry or washed	Mortar and Render
0-4mm Sand, dry or washed	M Grade sand, Concrete production, Block Pavers, Flags
10mm	Suitable for pathways and drives, concrete production. Pipe bedding
20mm	Suitable for pathways and drives, concrete production. Pipe Bedding
10-5mm
20-5mm
40mm	Sub Base and Type B drainage material
75mm	Sub base and Type B drainage material
150mm	Clean 6g Gabion material for civil engineering projects
40mm crusher run	Combination of crushed rock and stone dust creates a low void sub base material
75mm crusher run	Backfill, trench fill sub base
6F2	A recycled material used as bulk fill or cap and lay material. Good for Piling Mats
6F5	A recycled material used as bulk fill or cap and lay material
MOT Type 1	Granular sub base material, good load bearing properties
Rip Rap	Used for shoreline, bridge abutments, pilings
Dimensional Stone	Can be trimmed or cut to any shape or size.
Rock Armour	Sea/River defences, Stabilisation projects

 

Properties of Construction Aggregates

Physical Properties

The physical properties of construction aggregates, such as size, shape, texture, and grading, significantly influence their performance in concrete and asphalt applications.

• Size: Aggregates are classified by size, ranging from fine particles like sand to coarse aggregates like gravel and crushed stone. The size affects the workability and strength of the concrete mix.
• Shape: The shape of aggregates can be angular, rounded, or irregular. Angular aggregates interlock better and provide higher strength, while rounded aggregates improve workability.
• Texture: The surface texture of aggregates impacts the bonding between the aggregate and the cement paste in concrete. Rough-textured aggregates provide better bonding and strength.
• Grading: Proper grading of aggregates ensures a well-distributed particle size, which enhances the density and strength of the mix.

These physical properties are crucial in determining the quality and performance of construction materials. 

Mechanical Properties

The mechanical properties of construction aggregates, including strength, durability, and abrasion resistance, are essential for their performance in different construction applications.

• Strength: Aggregates must have sufficient strength to withstand the loads and stresses imposed on them in concrete and asphalt applications. High-strength aggregates contribute to the overall strength of the structure.
• Durability: Durability refers to the ability of aggregates to resist weathering, chemical attack, and freeze-thaw cycles. Durable aggregates ensure the longevity and stability of the construction material.
• Abrasion Resistance: Aggregates used in surfaces subjected to wear and tear, such as roads and pavements, must have high abrasion resistance to maintain their integrity and appearance over time.

Understanding and selecting aggregates with the appropriate mechanical properties is vital for the success of construction projects.

Sustainable Aggregate Practices at Armstrongs

Sustainability is a core value at Armstrongs. We prioritise recycling and the reuse of materials to minimise environmental impact. Any excess stone from blasts carried out to produce large stone for building projects is turned into aggregates.  

Armstrongs is FORS Accredited 

As part of our ongoing efforts to continually improve our working practice we are delighted to announce that Armstrongs Aggregates LTD is now FORS accredited.

The Fleet Operator Recognition Scheme (FORS) is a voluntary accreditation scheme for fleet operators which aims to raise the level of quality within fleet operations.

Achieving our FORS accreditation demonstrates our long term commitment to our customers, staff and the industry; as an industry pace setter and a leader in fleet transport best practice.

Instilling a mindset of continual improvement, joining an elite group of operators that boast exemplary levels of safety, efficiency and environmental awareness.

Aggregates FAQs 

What is construction aggregate?

Construction aggregate is a broad category of coarse- to medium-grained particulate material used in construction, including sand, gravel, crushed stone, slag, and recycled concrete. These materials are essential components in creating concrete, asphalt, and other construction materials.

What types of aggregate are used in construction?

There are three main types of aggregates used in construction: natural aggregates (such as sand, gravel, and crushed stone), recycled aggregates (such as recycled concrete and asphalt), and manufactured aggregates (such as slag and expanded clay). Each type serves specific purposes based on its properties and the requirements of the construction project.

How are construction aggregates produced?

Construction aggregates are produced through a series of processes, starting with the extraction of raw materials from quarries. These materials are then crushed, screened, and washed to achieve the desired size and quality. Armstrongs employs state-of-the-art machinery and strict quality control measures to ensure that our aggregates meet industry standards.

What is aggregate used for in construction?

Aggregates are used in various construction applications, including as a key component in concrete and asphalt production, as a base material for roads and foundations, and in decorative applications such as landscaping and pathways. They provide essential structural support, durability, and stability to construction projects.

How does Armstrongs ensure the quality of its aggregates?

Armstrongs ensures the quality of its aggregates through rigorous quality control processes at every stage of production. From quarrying and extraction to processing and final inspection, we adhere to strict standards to ensure consistency and performance. Our commitment to quality is reflected in the high satisfaction of our customers.

Where can I buy construction aggregates?

You can purchase construction aggregates directly from Armstrongs. We offer a wide range of high-quality aggregates to meet various project needs. Our knowledgeable team is available to assist you in selecting the right materials and providing technical support. Contact us for more information and to place your order.

How can I choose the right aggregate for my project?

Choosing the right aggregate for your project involves considering factors such as the project’s specific requirements, the properties of the aggregate, environmental conditions, and sustainability. Armstrongs’ team of experts can help you assess these factors and recommend the most suitable aggregates for your needs.

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At Armstrongs, we supply a wide range of aggregate materials to the construction industry for a range of different applications, direct from our own quarries.

Construction aggregates play an important role in building and infrastructure projects, offering essential support and strength to various structures. In this guide, we will explore the different types of construction aggregates, their uses, and the benefits they offer.

What is Construction Aggregate?

Construction aggregate is a broad category of coarse- to medium-grained particulate material used in construction. It includes materials such as sand, gravel, crushed stone, slag, and recycled concrete. Aggregates are used in various construction applications, from residential buildings to major infrastructure projects, providing foundational strength and stability.

Types of Construction Aggregate

Natural Aggregates

Natural aggregates are sourced from natural deposits and are commonly used in construction projects. These include:

• Sand: Fine aggregate used in concrete and mortar, providing bulk, strength, and stability.
• Gravel: Coarse aggregate typically used in concrete mixes, road construction, and drainage systems.
• Crushed Stone: Made from crushed natural rock, it is used in construction, road bases, and as a binding material.

Recycled Aggregates

Recycled aggregates are produced from recycled materials such as demolished concrete, asphalt, and other construction debris. Examples include:

• Recycled Concrete: Created by crushing old concrete and used for road base, backfill, and new concrete mixes.
• Recycled Asphalt: Made by reprocessing used asphalt and commonly used in road construction and repair.

Using recycled aggregates offers several benefits, including reducing waste sent to landfills, conserving natural resources, and often providing cost savings. They are an eco-friendly alternative to natural aggregates, contributing to sustainable construction practices.

Manufactured Aggregates

Manufactured aggregates are produced through industrial processes. Examples include:

• Slag: A byproduct of steel production, slag is used in road construction, concrete, and as a soil amendment.
• Expanded Clay: Lightweight aggregate made from heating clay, used in lightweight concrete, insulation, and hydroponics.

Manufactured aggregates are designed to meet specific engineering standards and offer unique properties, such as improved strength and durability.

Natural Aggregate at Armstrongs

Natural aggregates are valued for their strength, versatility, and availability. At Armstrongs, we provide natural aggregates from our 5 quarries across the North West and Cumbria including Shap, Brinscall, Montcliffe, Pilkington 1 & 2 and Waddington Fell. 

The Extraction Process

The first step in the process of creating natural aggregate is identifying the perfect place to blast for the required stone. Once the right place in the quarry has been found, holes are drilled to the depth that is needed, depending on the amount of aggregate required. 

The holes are then filled with explosives, which allow us to release the stone we need for making the aggregate. 

Then it’s time for the blast! Once everyone has evacuated to a safe distance, we give the all clear and an almighty rumble is sent through the quarry as the rock is blasted.

Usually, this produces large pieces of stone that would otherwise be used for projects that require cut stone, such as buildings. However, for aggregate, we collect the large pieces and bash them using an excavator with a pecker tip.

We then put the smaller broken down pieces of stone into the crusher machine, which does exactly what it says on the tin! The stone is crushed down to various sizes which is sorted into categories.

Using an excavator and a truck, the pile of smaller aggregate is then transported to the screener, which will wash and sort the piles.

The Screening And Washing Process

The screener is a large vibrating box which consists of a number of various sized screens and meshes. This will separate the different sized aggregates like a sieve until they are all separated and washed.  

These sieves will separate the different sizes of aggregates and create t piles which will vary in sizes. During this screening process, the aggregate is washed to remove any unwanted materials such as clay, silt and dirt which may be present. We do this so that there is no drying effect or impurities in the future which could lead to cracking.

The various sized aggregates can be used for different functions. At Armstrongs, we produce a range of aggregate sizes from 2mm and 10mm all the way to 75mm and the gabion sized aggregate 150mm.

What is Aggregate Used for in Construction?

Structural Uses

Aggregates help with the structural integrity of concrete and asphalt, two of the most commonly used materials in construction. In concrete production, aggregates act as a filler material that provides bulk, strength, and stability to the mix.

The combination of aggregates with cement and water creates a robust material capable of withstanding significant loads and environmental stresses. Similarly, in asphalt production, aggregates are mixed with bitumen to create a durable and flexible material suitable for road surfaces.

The importance of aggregates extends to foundation construction, where they are used to create a stable base for buildings and infrastructure. Aggregates help distribute the weight of the structure evenly and provide necessary drainage, preventing water accumulation that could undermine the foundation.

Coastal Protection

Another example of aggregates and their uses are gabion baskets, which is a large aggregate inside a metal mesh basket. These gabion baskets create a sturdy structure which is perfect for coastal management.For this, we use a 150mm sized aggregate. Gabions are used in garden purposes and also civil engineering projects as well. 

Train Track Aggregate

Have you ever noticed the stone which is laid between and around the tracks which trains run on? Large and rough aggregate is used to hold down the cross tie pieces of wood between the tracks, so that they do not separate. This also helps to absorb the vibrations from the trains themselves.

Decorative Uses

Beyond their structural and coastal applications, aggregates are also used for decorative purposes in landscaping and construction. Decorative aggregates, such as coloured stones, pebbles, and gravel, are employed to enhance the aesthetic appeal of outdoor spaces. They are commonly used in pathways, garden beds, and as ground cover to create visually pleasing and low-maintenance landscapes.

In decorative concrete, aggregates can be exposed to create unique textures and patterns. This technique, known as exposed aggregate concrete, is popular for driveways, patios, and walkways. It combines the functionality of concrete with the natural beauty of aggregates, offering both aesthetic and functional benefits.

Here’s a table to demonstrate different aggregate sizes and their example uses:

Aggregate Product	Application example
0-2mm Sand, dry or washed	Mortar and Render
0-4mm Sand, dry or washed	M Grade sand, Concrete production, Block Pavers, Flags
10mm	Suitable for pathways and drives, concrete production. Pipe bedding
20mm	Suitable for pathways and drives, concrete production. Pipe Bedding
10-5mm
20-5mm
40mm	Sub Base and Type B drainage material
75mm	Sub base and Type B drainage material
150mm	Clean 6g Gabion material for civil engineering projects
40mm crusher run	Combination of crushed rock and stone dust creates a low void sub base material
75mm crusher run	Backfill, trench fill sub base
6F2	A recycled material used as bulk fill or cap and lay material. Good for Piling Mats
6F5	A recycled material used as bulk fill or cap and lay material
MOT Type 1	Granular sub base material, good load bearing properties
Rip Rap	Used for shoreline, bridge abutments, pilings
Dimensional Stone	Can be trimmed or cut to any shape or size.
Rock Armour	Sea/River defences, Stabilisation projects

Properties of Construction Aggregates

Physical Properties

The physical properties of construction aggregates, such as size, shape, texture, and grading, significantly influence their performance in concrete and asphalt applications.

• Size: Aggregates are classified by size, ranging from fine particles like sand to coarse aggregates like gravel and crushed stone. The size affects the workability and strength of the concrete mix.
• Shape: The shape of aggregates can be angular, rounded, or irregular. Angular aggregates interlock better and provide higher strength, while rounded aggregates improve workability.
• Texture: The surface texture of aggregates impacts the bonding between the aggregate and the cement paste in concrete. Rough-textured aggregates provide better bonding and strength.
• Grading: Proper grading of aggregates ensures a well-distributed particle size, which enhances the density and strength of the mix.

These physical properties are crucial in determining the quality and performance of construction materials. 

Mechanical Properties

The mechanical properties of construction aggregates, including strength, durability, and abrasion resistance, are essential for their performance in different construction applications.

• Strength: Aggregates must have sufficient strength to withstand the loads and stresses imposed on them in concrete and asphalt applications. High-strength aggregates contribute to the overall strength of the structure.
• Durability: Durability refers to the ability of aggregates to resist weathering, chemical attack, and freeze-thaw cycles. Durable aggregates ensure the longevity and stability of the construction material.
• Abrasion Resistance: Aggregates used in surfaces subjected to wear and tear, such as roads and pavements, must have high abrasion resistance to maintain their integrity and appearance over time.

Understanding and selecting aggregates with the appropriate mechanical properties is vital for the success of construction projects.

Sustainable Aggregate Practices at Armstrongs

Sustainability is a core value at Armstrongs. We prioritise recycling and the reuse of materials to minimise environmental impact. Any excess stone from blasts carried out to produce large stone for building projects is turned into aggregates.  

Armstrongs is FORS Accredited 

As part of our ongoing efforts to continually improve our working practice we are delighted to announce that Armstrongs Aggregates LTD is now FORS accredited.

The Fleet Operator Recognition Scheme (FORS) is a voluntary accreditation scheme for fleet operators which aims to raise the level of quality within fleet operations.

Achieving our FORS accreditation demonstrates our long term commitment to our customers, staff and the industry; as an industry pace setter and a leader in fleet transport best practice.

Instilling a mindset of continual improvement, joining an elite group of operators that boast exemplary levels of safety, efficiency and environmental awareness.

Aggregates FAQs 

What is construction aggregate?

Construction aggregate is a broad category of coarse- to medium-grained particulate material used in construction, including sand, gravel, crushed stone, slag, and recycled concrete. These materials are essential components in creating concrete, asphalt, and other construction materials.

What types of aggregate are used in construction?

There are three main types of aggregates used in construction: natural aggregates (such as sand, gravel, and crushed stone), recycled aggregates (such as recycled concrete and asphalt), and manufactured aggregates (such as slag and expanded clay). Each type serves specific purposes based on its properties and the requirements of the construction project.

How are construction aggregates produced?

Construction aggregates are produced through a series of processes, starting with the extraction of raw materials from quarries. These materials are then crushed, screened, and washed to achieve the desired size and quality. Armstrongs employs state-of-the-art machinery and strict quality control measures to ensure that our aggregates meet industry standards.

What is aggregate used for in construction?

Aggregates are used in various construction applications, including as a key component in concrete and asphalt production, as a base material for roads and foundations, and in decorative applications such as landscaping and pathways. They provide essential structural support, durability, and stability to construction projects.

How does Armstrongs ensure the quality of its aggregates?

Armstrongs ensures the quality of its aggregates through rigorous quality control processes at every stage of production. From quarrying and extraction to processing and final inspection, we adhere to strict standards to ensure consistency and performance. Our commitment to quality is reflected in the high satisfaction of our customers.

Where can I buy construction aggregates?

You can purchase construction aggregates directly from Armstrongs. We offer a wide range of high-quality aggregates to meet various project needs. Our knowledgeable team is available to assist you in selecting the right materials and providing technical support. Contact us for more information and to place your order.

How can I choose the right aggregate for my project?

Choosing the right aggregate for your project involves considering factors such as the project’s specific requirements, the properties of the aggregate, environmental conditions, and sustainability. Armstrongs’ team of experts can help you assess these factors and recommend the most suitable aggregates for your needs.

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Recycled concrete aggregate plays an important role in construction projects. From road construction to foundation work, RCA helps reduce waste, conserve natural resources, and promote environmentally friendly building practices.

At Armstrongs, we provide top-quality aggregate materials for a range of different applications, including RCA.  In this guide, we’ll be explaining exactly what recycled concrete aggregate is, what it’s used for and the benefits it has to offer.

What is Recycled Concrete Aggregate?

Recycled concrete aggregate (RCA) is a material derived from the crushing and processing of construction and demolition waste, primarily consisting of concrete. This material often includes other aggregate components such as sand, gravel, slag, and crushed stones. RCA is specifically classified as recycled concrete aggregate when the primary material used is concrete.

The production of RCA involves collecting and processing concrete waste from various sources, such as demolished buildings, roads, and bridges. This waste material is then crushed and refined to produce aggregate of a specific size and quality.

The result is a cost-effective and sustainable alternative to traditional quarried aggregates, helping to reduce the burden on landfill sites and preserve natural resources.

At Armstrongs, we take pride in producing high-quality RCA that meets stringent industry standards. Our commitment to quality and sustainability ensures that our recycled concrete aggregate is a reliable choice for your construction needs.

How is Recycled Concrete Aggregate Produced?

Collection and Sorting

The production of recycled concrete aggregate (RCA) begins with muck away, the process of removing inert waste from various sites. Muck away can be classified into three categories: inert, hazardous and non-hazardous.

Inert muck away is waste that hasn’t gone through any chemical physical or biological changes and thus is less likely to affect any other matter that it comes into contact with. Inert muck away includes brick, concrete, hardcore soil and subsoil.

Hazardous muck away is defined as a gathering of waste that has properties that make it harmful to human health and the environment.

Non-hazardous materials can include a collection of different waste products that are considered not harmful to the environment and human life.

Once our tipper trucks are full of waste they will be transported to our inert landfill at Pilkington Quarry in Horwich. We separate the waste by classification of inert and Non-Hazardous waste. Inert waste such as soil is returned to the land. However, other materials such as brick and concrete are recycled.

Crushing Process

Once the concrete waste has been sorted and cleaned, it is fed into crushing machines. These machines use impact force to break down large chunks of concrete into smaller, more manageable pieces. The crushing process is typically carried out in stages, using different types of crushers to achieve the desired size and consistency.

Refining and Mixing

After the initial crushing, the material undergoes further refinement to remove any remaining impurities and to achieve a uniform size. The refined concrete is then mixed with other aggregate materials such as sand and gravel to create a product that meets specific engineering requirements.

This mixture enhances the consistency and density of the recycled concrete aggregate, ensuring it performs well in various construction applications.

Properties of Recycled Concrete Aggregate

Recycled concrete aggregate has several notable physical properties. It is available in various sizes, ranging from fine particles to larger chunks, allowing it to be used in a wide range of construction applications. The texture of RCA is generally rough, which can improve the bonding properties when used in concrete mixes.

In terms of durability, RCA is comparable to natural aggregates, making it suitable for load-bearing applications. Its strength characteristics depend on the quality of the original concrete and the thoroughness of the crushing and refining process.

Environmental Properties

One of the significant advantages of using recycled concrete aggregate is its lower energy consumption during production compared to traditional concrete. The recycling process requires less energy and reduces the need for natural resources, such as virgin aggregate and water. 

Additionally, using RCA helps to decrease the environmental impact associated with mining and quarrying natural aggregates. It also reduces the amount of waste that ends up in landfill sites, promoting a more sustainable construction industry.

Advantages of Using Recycled Concrete Aggregate

Cost-Effectiveness

One of the primary advantages of using recycled concrete aggregate (RCA) is its cost-effectiveness. RCA is generally less expensive than quarried stone due to the lower costs associated with sourcing and processing.

This can result in significant savings for construction projects. Additionally, companies using RCA may be eligible for tax rebates and incentives for employing sustainable practices, further enhancing the cost savings.

Environmental Benefits

Recycled concrete aggregate offers substantial environmental benefits. By using RCA, the amount of construction waste sent to landfill sites is significantly reduced, which helps in conserving landfill space.

Recycling concrete also reduces the need for mining natural aggregates, thereby preserving natural resources and minimising environmental degradation. This practice promotes a more sustainable construction industry.

Performance Benefits

RCA is known for its durability and suitability for various ground conditions, including wet or soft soils. Its rough texture enhances the bonding properties in concrete mixes, leading to strong and durable construction materials. 

Additionally, RCA has improved water absorption properties compared to traditional concrete, which can be beneficial in specific applications requiring better drainage and seepage control.

Uses of Recycled Concrete Aggregate

Construction Applications

Recycled concrete aggregate is highly versatile and can be used in various construction applications. It is particularly effective for compaction purposes, making it ideal for building foundations.

RCA is also suitable for use in wet or soft ground conditions, providing a stable and durable base for construction projects.

Specific Uses

Beyond general construction applications, RCA is used in several specific scenarios. It serves as an excellent material for pipe bedding, offering stability and protection for underground pipes. RCA is also commonly used for backfilling trenches and landscaping projects.

Additionally, Armstrongs produces specialised recycled aggregates such as 6F2 and 6F5, a durable aggregate formed from crushed concrete or brick hardcore, and green MOT Type 1, a blend of clean quarry stone and quality aggregates.

Armstrongs’ Commitment to Quality and Sustainability

Our Production Process

At Armstrongs, we use state-of-the-art machinery and advanced processes to produce high-quality recycled concrete aggregate (RCA). Our sites are equipped with the latest crushing and screening technology to make sure that the aggregate produced meets the highest standards of consistency and performance.

Each step of our production process, from collection to refining, is carefully managed to maintain the quality of our recycled concrete materials. This commitment to excellence guarantees that our RCA is reliable, durable, and suitable for a wide range of construction applications.

Environmental Responsibility

Armstrongs is dedicated to reducing environmental impact through sustainable practices. One of our key initiatives is the production of recycled aggregate at our Head Office in Horwich. By recycling concrete and other construction materials, we minimise the amount of waste sent to landfill sites and reduce the need for virgin aggregate.

This not only conserves natural resources but also lowers the carbon footprint of our operations. Our commitment to sustainability in construction ensures that our practices contribute to a healthier environment and a more sustainable future.

Learn more about Armstrongs’ Aggregates

For more information on each of Armstrongs’ aggregates, don’t hesitate to contact our friendly team. Call 01204 668021 or send us an email today!

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