Concrete forms work is the backbone of concrete construction projects. It ensures that our concrete takes the desired shape once it hardens. From slabs and test cylinders to complex foundations and countertops, concrete forms turn fresh concrete into stable, durable finished products for use in the construction and material testing industries. Without them, we would have no way of ensuring our concrete is the right shape and size for its intended purpose.
But let’s step back. What is a concrete form, and what do you need to know when you use one?
In this blog, we’ll explore everything you need to know about concrete forms. You’ll learn the different types, how to cut costs, and our top tips to ensure you achieve flawless formwork every single time.
What are concrete forms?
Poured concrete is fluid before it sets. It can flow into tight spaces, fill voids and maneuver around obstacles. These characteristics make concrete an excellent material when it comes to ensuring complete coverage in complex foundations. But how do we ensure the concrete only goes where we want it? Concrete forms, of course!
Concrete forms hold wet concrete in place until it fully hardens and reaches maximum strength. They are an essential part of almost every construction project and structure design. A construction expert can create a concrete form of any shape and size. From large-scale foundation work to small cylinder and cube molds for material testing, concrete forms allow us to create robust and durable concrete at a desired shape time and time again, making it essential to choose the right type for your specific needs.
There are many things to consider when choosing the correct concrete forming. Concrete is heavy, weighing around 150 pounds per square foot. Your form must hold the concrete’s weight to prevent blowouts and leaks. Let’s look at some of the things you should consider when using them in your next construction project.
11 things you should know about concrete forms
Let’s explore eleven things you should know when using concrete forms in your next concrete construction project.
1) Concrete forms are versatile and reliable
Concrete can be tough to manage. It’s heavy and viscous, meaning it can be challenging to control without proper planning. Concrete forming ensures that concrete mixtures hold their place while they are set.
Whether it’s creating supports for a new fence structure, a foundation for a structure, or concrete slabs for paving, concrete forms are a versatile and vital part of almost all construction projects.
2) Concrete forms aren’t just for large-scale structures
Most people picture large foundations and complex structures when imagining concrete forms – but this isn’t the only way to use formwork. Concrete forms are also essential in the material testing industry because they allow testers to create standardized, reliable concrete shapes for concrete strength tests.
For example, concrete cube molds and concrete test cylinders are vital when creating samples for compressive strength testing, while concrete beam molds are a crucial component of flexural strength tests. Adding a concrete mixture to a form allows the tester to create consistent, reliable molds for material testing every single time.
In addition, consider using concrete forms as a way to enhance your concrete structures with decoration. Ornamental and decorative concrete forms are an excellent way to create visually stunning architectural elements to spruce up your concrete surfaces.
3) Timber is the standard material for concrete formwork
Wood forms are the most common type of concrete form. Timber is easy to shape, lightweight, cost-effective, and surprisingly durable. The flexibility of wooden forms also reduces the risk of strains and breakages.
When choosing the right timber formwork, always ensure the wood doesn’t have any loose knots or weak points, as these could break or loosen, allowing concrete to escape. In addition, timber forms may buckle or warp if they absorb moisture when in contact with the concrete. Always use a quality sealant to reduce the risk of absorption.
4) Other concrete form materials are gaining popularity
While timber is still the most common choice for formwork, other materials are gaining popularity. Let’s explore some other important concrete form types used in construction and material testing.
Insulated concrete forms
Insulated concrete forms (ICFs) are hollow blocks made of insulating material that fit together like bricks. Construction experts build ICFs on the foundation slab and reinforce the blocks’ interior with steel. Concrete is then poured between the two sides of the ICF form and allowed to set.
ICFs are increasingly popular for large-scale foundations and concrete walls. Their modular design allows for creating complex shapes. Once the concrete sets, the ICFs remain in place, providing excellent insulation and soundproofing. However, ICFs have a higher initial cost than other forms and require specialized knowledge for installation, which may not suit all budgets or expertise levels.
Steel
Some concrete forms are made of steel plates or panels assembled to create formwork. Steel is durable and stable, making it ideal for forms that need high strength.
Like Insulated Concrete Forms (ICFs), steel forms are usually pre-built. The construction team buys the right combination of forms and joins them with nuts, bolts, form ties, clamps, fasteners, or clips.
The main benefit of steel forms is their reusability. They can be used for thousands of cycles with proper maintenance and cleaning, making them a cost-effective and sustainable option. Additionally, steel doesn’t absorb moisture, so no sealant is needed as with wooden forms. However, steel forms are heavier and require technical expertise, which means more effort for transportation, handling, and installation.
Plastic
Plastic concrete forms are typically produced with high-density polyethylene (HDPE), polypropylene (PP), or polystyrene (PS) materials. It is resistant to moisture, highly durable, flexible, and lightweight, making it a versatile material for various concrete construction applications. The material also has a smooth surface, meaning concrete created with plastic forms typically has a more uniform, polished finish than other form types. Plastic forms are also highly effective for concrete flatwork, providing a user-friendly and durable solution for both professional and residential projects.
The affordability, portability, and reusability of plastic forms mean they are a staple in material testing. Many beam, cube, and cylinder molds are plastic because they form smooth, reliable concrete shapes with no surface irregularities that could affect the reliability of the finished product. That said, concrete isn’t as strong as other materials like steel or timber. For this reason, plastic may be unsuitable for construction applications that demand a high load capacity.
5) Concrete mixes matter
The mix you use in your construction project can significantly impact your concrete’s workability, flowability, and setting time. When choosing the right combination for your application, consider how complex your formwork is. Higher water content increases flowability, making it easier for your concrete to fill complex formwork. That said, too much water can negatively impact the compressive strength of your mix. It’s important to find the right balance for your project.
6) Let the mixture fully set
Ensure you always allow the right amount of time for the mix to set before removing the concrete form. The type of cement you use, ambient temperature, and water-to-cement ratio can each make the setting process take longer than anticipated. Always check your mixture’s exact specifications and curing time to prevent unnecessary damage or structural failure from premature form removal.
7) Reinforcement is key
Concrete reinforcement plays a crucial role in ensuring the structural integrity and load-bearing capacity of your formwork. Consider adding steel rebars and wire mesh in a grid pattern to add stability and tensile strength to your formwork.
8) Careful planning helps to cut costs
Pre-manufactured forming systems can reduce labor costs, but expenses increase if they aren’t reusable. Wastage in projects can be costly. Optimizing your framework design to minimize material waste improves efficiency. Though it may seem minor, the cost of additional materials can significantly affect long-term profits. Careful planning also helps avoid expensive mistakes.
9) Form release agents are vital
Designing and filling a concrete form is easy. Safely removing the temporary form once the concrete is set can be more challenging if you haven’t done the necessary prep work. Always apply a form release agent to the surfaces of your form. Doing so ensures the concrete won’t stick when you remove it, reducing the risk of surface defects.
10) Formwork inspection is essential
Your formwork may look flawless at first glance, but it’s vital to perform a closer inspection to identify potential problems. Minor defects, damages, misalignments, and loose fittings may be tough to spot from a distance, but any weak links will quickly become apparent once you pour in your concrete mixture. Check that every component and material is perfect before you add any concrete to your formwork.
11) Concrete is dangerous: take safety precautions
Concrete can be dangerous and should be handled with caution. Follow necessary safety precautions, get effective safety equipment, and ensure all staff are well-trained before working with concrete forms.
Where can I find the best concrete form for concrete testing?
The key to successful concrete is choosing high-quality, reliable molds. If you’re looking to create consistent concrete testing samples, CertifiedMTP can help. We stock a wide range of concrete forms for material strength testing, including cylinder molds, beam molds and cube molds.
All of our molds adhere to ASTM standards, so you can be confident that every sample you create will be as consistent, reliable, and high-quality as the last. We also offer molds in various different materials, including plastic, stainless steel, and cardboard. Whatever your needs, we have a form suited to your testing application.
We also offer a range of formwork accessories. From string holders and cleaning detergents to countertop forms and fastening nails, our range of tools ensures you get the results you need time and time again.
Can’t find what you’re looking for? Don’t hesitate to reach out. At CertifiedMTP, we’re committed to helping you find the best equipment for your next material testing project.
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