Concrete is one of the most widely used construction materials in the world. Although it has conventionally been used to make foundations, columns, beams and slabs, it can also be used to make walls with higher strength than typical masonry structures. Continue reading to understand what precast concrete wall panels are, types, applications and benefits of prefab concrete walls and learn how precast walls are fixed in buildings.
What are Precast Concrete Wall Panels?
Concrete is a calculated mix of cement, sand and aggregates, which is commonly combined with steel rebars to form a strong and durable material called Reinforced Cement Concrete (RCC). When concrete is poured into moulds and cured in controlled factory settings, it forms precast concrete wall panels. They are commonly referred to as prefabricated concrete walls or readymade concrete walls and are used as stronger and quicker alternatives to masonry structures.
Why Use Precast Concrete Wall Panels?
The benefits that prefabricated wall panels bring to the table are exceptional. These include:
- Strength: Concrete has extremely high compressive strength. When combined with reinforcements like steel bars, it also obtains high tensile strength. Thus, concrete precast walls can be used to form load-bearing structures that have a very high strength-to-weight ratio.
- Durability: Prefabricated concrete wall panels exhibit a high resistance to harsh environmental conditions, rusting, extreme climates, abrasion, fires and corrosion. They can last for multiple decades without undergoing any degradation.
- Uniform Quality: Since they are manufactured in controlled factory settings, precast concrete building panels have extremely uniform quality. Each of their properties—including compressive and tensile strength, aesthetics, size and flexural strength—is carefully tested before they are shipped to construction sites for installation. This level of quality control is difficult to achieve with conventional wall construction techniques like stone and brick masonry.
- Simple Installation and Dismantling: With standardised fixing techniques and procedures, prefab concrete wall panels can quickly and easily be installed with minimal labour on site, although higher transportation costs are involved. They can also be dismantled at the end of the building’s life cycle, allowing them to be reused in other projects.
- Finishing: Precast concrete wall panels can retain versatile finishes like paints, tile, panel or stone cladding and polishes easily. They can also be left exposed without any finishing if a raw, industrial aesthetic is desired.
Types of Precast Wall Panels
Types of Prefab Concrete Walls Based on Structural Function
According to the Indian Standard IS Code: 15916 (2011), prefab concrete panels can be classified into three types based on their structural function:
- Load Bearing Precast Concrete Walls: Load-bearing walls carry and help transfer building loads down to the foundation. When made of precast concrete, they have a minimum thickness of 150mm.
- Non-Load Bearing Walls: These walls do not carry any structural loads and are used as barriers to protect from environmental forces or as internal partitions. They can be as thin as 100mm.
- Shear Walls: Walls designed especially to resist lateral forces like those caused by heavy winds, hurricanes and earthquakes are called shear walls. They are particularly beneficial for high-rise structures, where wind loads are high. Their minimum thickness when made with precast concrete is typically 150mm.
Types of Prefabricated Concrete Walls Based on Composition
- Solid or Single Skin Precast Concrete Panels: These are the most commonly used types of precast concrete wall panels and consist of solid concrete reinforced with steel, glass fibre or FRP rebars. They have a thickness ranging from 100 – 250mm, depending on their structural function.
- Hollow Core Concrete Panel Wall: In such panels, the amount of concrete is reduced by using hollow voids, pipes or other plastic/ metal sections. This significantly reduces the weight of the panel and enables easier routing of plumbing and electrical lines. However, these panels are much thicker (generally a minimum of 200mm).
- Sandwich Precast Panels: Sandwich RCC precast walls consist of an insulating layer sandwiched between the outer concrete layers. Materials like rockwool or foam are used as the core layer to provide building insulation by reducing the heat exchange rate and enhancing thermal comfort.
How is a Precast Wall Fixed?
Precast concrete wall panels generally have grooves that allow them to be interlocked into each other. However, additional provisions for connections are typically provided to ensure stability and strength between different precast building panels. These connections can be of the following types:
- Bolted Connections: To enable these connections, holes are provided in the precast concrete units, through which steel bolts can be passed and fixed after alignment on the site. It is important to ensure that the bolt slots are neither undersized nor oversized to maintain strength and stability. Typically, bolts with standard diameters of 19mm, 25mm or 32mm and with varying lengths are used.
- Welded Connections: Here, steel plates or rods are embedded into the wall unit at its edge and these rods/ plates are welded onto the steel elements of the adjacent precast concrete unit. The size, type, location and length of welds depend on the structural function and size of the precast wall units.
- Anchored Connections: These connections are generally made when precast concrete wall panels need to be fixed directly on foundations or footings. Anchor bolts are generally post-installed, meaning that holes are made on-site after alignment of the wall units by drilling. Once the anchor bolts are fixed, the space around them is filled up with grout or adhesives.
Applications of Precast Walls
Some of the common applications of precast concrete wall units are as follows:
- Precast retaining walls can resist high amounts of earth pressure with ease, especially when reinforced or complemented by buttresses and other lateral supports. Separate precast concrete retaining wall blocks with a height of around 1 foot can be fixed to each other to form walls with the desired heights.
- RCC boundary walls act as impenetrable layers of security with their high strength. Precast concrete boundary walls can be cost-effective as they do not require any finishing.
- Concrete panels for exterior walls are extremely durable, have high strength and can resist adverse weather conditions.
- Interior precast concrete wall panels are quick and easy to erect. However, they may be more expensive than conventional interior partition walls.
- These elements are extremely beneficial in the construction of high-rise structures with modular floors, such as apartments, office buildings and hospitals. The precast concrete walls cost is also reduced when multiple modular units are used here.
Using Precast Concrete Wall Panels in Your Project
To ensure adequate strength and stability of precast concrete wall panels, it is important to source them from the right manufacturers and suppliers. Brick & Bolt, one of the leading construction companies in India, is affiliated with the top manufacturers and brands for procuring and supplying building materials. The company also conducts 470+ quality checks (QASCON) for all its projects, ensuring that supreme quality is maintained throughout. Reach out to Brick & Bolt today to be assured that your dream home or commercial construction project is executed with the best materials like precast walls!
Apoorva H P Achar 
Hemali Patel