NEWS

What is an Expansion Joint, and Why Do You Need Them in Concrete?

28.03.23
Construction Products

Do you need concrete expansion joints for your next construction project? Discover the best types and products available to ensure the integrity of your structure.

Whenever working with concrete, it’s vital to understand its altering condition and how that may affect the structural integrity of your construction.

So, whether you’re laying a driveway or using separate concrete slabs for a construction project, planning how you position your expansion joints is a vital first step.

Today we’ll discuss the different types of expansion joints and what products you can use to support your concrete construction project.

Our concrete expansion joint solutions can serve multiple project types, with UK-wide delivery and an extensive range of sizes available.

What is an Expansion Joint?

Expansion joints, also called “movement joints” and “control joints” provide a gap within concrete structures to allow concrete to expand and contract. Typically, the gap lies between one concrete structure and whatever concrete it adjoins.

The purpose of expansion joints is to ensure the structural integrity of a concrete structure, avoiding cracking as the building moves or expands under pressure and temperature changes. Expansion joints can also absorb vibration and sustain soil movement, whether from the result of heavy vehicles or even earthquakes.

Expansion joints are used for multiple construction projects, including:

– Buildings
– Bridges
– Pavements/driveways/foundations
– Railway tracks
– Piping systems
– Shipbuilding

Without prior industry knowledge, it will surprise you to know the extent seasonal weather changes can force a building or structure to expand or contract. All construction projects must account for these potential adverse effects. Such issues make expansion joints an essential assembly feature for numerous concrete structures.

Referred to as coefficient expansion in concrete, the average value of around ten millionths per degree Celsius (10×10-6/C). However, thermal expansion and contraction depending on the concrete aggregate type, such as shale, limestone, siliceous gravel, and granite. Then there is the cementitious material content and water-cement ratio to consider before the temperature range, concrete age, and relative ambient humidity.

With the increasing demand for concrete roads and building construction worldwide, the supply for expansion joints is rising, witnessing a 6% CAGR for 2021 and 2030.

Types of Expansion Joints

Due to the versatility of construction, expansion joints come in numerous variations and from multiple materials, including metal, rubber and fabric.

General distinctions between bridges, masonry, railway, piping, and ducted air systems. However, here is an extensive list of the types of expansion joints you can expect to find with specific purposes and requirements:

– Single expansion joints
– Hinged expansion joints
– Rectangular expansion joints
– Universal expansion joints
– Thick wall expansion joints
– In-line pressure balanced expansion joints
– Externally pressurised expansion joints
– Elbow pressure balanced expansion joints
– Toroidal expansion joints
– Slip-type expansion joints
– Refractory lined expansion joints
– Gimbal expansion joints

While piping systems require pressurised variations and single expansion joints are sufficient for smaller projects, finding the type you need is essential for your structure.

Do You Need Expansion Joints in Concrete?

Concrete naturally shrinks as it dries before it expands or contracts depending on the ambient temperature. And with the unpredictable nature of British weather, construction projects must be extra aware when planning their concrete project.

Your expansion joint is only necessary when the concrete meets another structure, such as a building or attaching to another concrete slab. If you’re building a bridge or building, avoiding your concrete cracking is paramount to the safety of your structure.

When Do You Need an Expansion Joint in Blockwork?

Concrete blockwork is known to move, particularly with contraction in the UK. Therefore, we recommend you include expansion joints in block terraces containing over three houses. These expansion/movement joints should be in the outer leaves at 12 meters centres or stated otherwise by your designer.

For general concrete blockwork, the vertical spacing between expansion blocks should sit between six and nine meters apart.

Expansion joints are not necessary for single-block masonry walls unless the walls are over six meters high. For concrete blockwork, the general wall of vertical spacing between expansion blocks should sit between six and nine meters apart.

Expansion Joint Products to Add to Your Shopping List

At Hickman & Love, we supply a range of expansion products that can help you with your concrete construction projects. As specialists in reinforced concrete, we’re a quality-assured company with a wealth of industry experience.

Here is a list of our expansion joint products to fulfil your needs:

Expansion Joint Foam

Expansion joint foam works as a joint filler for its lightweight, clean and easy-to-use properties. Transferable across all building surfaces, our expansion joint foam has high chemical resistance alongside oil and ozone resistance.

Available in numerous sizes, from 10 x 100mm up to 25mm x 250mm, you can place your order online and request a convenient delivery date, time, and location.

Wood Fibre Fillerboard

Wood fibre filler board is ideal for making concrete slabs and wall constructions as an industry-standard expansion joint product.

Hickman & Love offers premium Bitumen impregnated wood fibre filler board sheets, providing excellent resistance to compression at a density of 230kg/m3.

Our wood fibre filler boards are low-cost and available in the following dimensions and quantities:

– WFB12 – 12mm (2133x1219mm) – Qty 80
– WFB20 – 20mm (2133x1219mm) – Qty 50
– WVF25 – 25mm (2133×1219) – Qty 40

You can also use the fibre board with PVC void formers to create sealant voids boasting superior recovery characteristics. This product is ideal as an expansion joint filler for making concrete slabs and wall constructions.

Corkfill

For water retaining assurance, invest in our Bitumen Bonded Corkfill, perfect for civil and structural expansion joints. Our Corkfill is an ideal waterproof joint expansion solution as it will not absorb moisture.

We offer superior Bitumen Bonded Corkfill boards in the following three sizes:

– CF13 – 13mm (2130 x 914mm) – Qty 80
– CF19 – 19mm (2130 x 914mm) – Qty 50
– CF25 – 25mm (2130 x 914mm) – Qty 40

Corkfill makes for another excellent expansion joint solution that can aid the structural integrity of your next concrete project.

Speak to Concrete Joint Expansion Experts

For over 80 years, we’ve been leading the way in the steel reinforcement fabrication market.