Introduction
The enduring popularity of concrete flooring continues to dominate the landscape of industrial, commercial, and even residential construction thanks to its durability and cost-effectiveness.
Yet, as with any surface, concrete may begin to degrade under the pressure of heavy traffic, impact, and abrasion. This is where Dry Shake Hardeners for Concrete Floors come in.
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These are surface-applied products that you incorporate to improve concrete flooring performance in the most demanding environments, such as warehouses, factories, parking garages, and retail space.
Dry shake hardeners have been around for some time now, but their importance has grown over the past few years as demand has increased for longer-lasting, low-maintenance, and attractive concrete flooring.
This blog will explore what dry shake hardeners are, what benefits they provide, classifications of hardeners, and techniques for applying them so that contractors and project owners are informed when choosing concrete flooring options.
What are Dry Shake Hardeners?
Dry shake hardeners are unique, pre-blended powder materials that are spread uniformly over freshly placed concrete during the finishing stage, for the concrete to accept it.
They are comprised of a mixture of specially graded aggregates of either metallic or non-metallic particles embedded in fine and coarse aggregate, Portland cement, colored pigments, and likely several admixtures, that will improve performance.
After the dry shake hardeners are evenly spread across the new concrete and integrated into the surface using trowels and other tools, they significantly improve the surface characteristics of concrete.
The use of dry shake hardeners will enhance surface characteristics by increasing surface hardness, which adds abrasion resistance and surface durability. These are critical factors in preserving the integrity and aesthetics of concrete subjected to extreme traffic.
There are two basic types of dry shake hardeners depending on the needs of the application:
1. Metallic Floor Hardeners: metallic floor hardeners contain metalic aggregates like aluminum or copper and create a high durability surface for areas with extremely high traffic and heavy industrial use.
Warehouses, manufacturing, and other large operations that require heavy-duty use are ideal candidates for metallic hardeners.
2. Non-metallic Floor Hardeners: Non-metalic floor hardener or a mineral aggregate such as quartz or silica, and are appropriate for light industrial, commercial or retail use.
These products will perform well, but also provide a more polished looking aesthetic in environments where looks matter.
Once dry shake hardeners are applied, they become integrated into the top layer of the concrete slab, which provides a denser and tougher finish that does not harm the integrity of the substructure below.
The integration into the top layer enhances the engineered performance of the surface and extends the life of the concrete, which adds value for a variety of projects from residential use to commercial and industrial applications.
Benefits of Dry Shake Hardeners
1. TIME
Dry shake hardeners significantly improve the concrete finishing operations and reduce the time involved in many instances compared to traditional concrete surface hardening methods.
Because the hardeners are placed directly onto the surface during the finishing operations, the finishing process is uninterrupted, meaning there is no need to waste time and efforts for multiple surface applications that lengthen the construction process.
Thus, reducing the time and effort in the construction process leads to a more efficient process and faster occupancy of the finished space.
2. ECONOMY
Dry shake hardeners are a great investment in the long run for a cost-effective and economical performance. The investment in dry shake hardeners increases the life expectancy of concrete floors, which results in fewer repairs and maintenance fees.
This is incredibly valuable in high-traffic and heavy-duty spaces such as warehouses and manufacturing floors, where the cost of repairs and maintenance over the life of the concrete creates measurable ROI.
3. DURABILITY
The key benefit of dry shake hardeners is that they can greatly improve the durability of concrete surfaces. When hardeners are added to concrete, they make the flooring more resistant to abrasion, impact and general surface wear.
This is especially important in environments with heavy machinery, forklifts and heavy carts which put severe conditions on flooring. Subsequently, repair and replacement of damaged floor surfaces is less likely in the long run.
4. AESTHETICS
In addition to some structural advantages, dry shake hardeners come in many colors and finishes which allow for aesthetic customization while not compromising performance.
Colored non-metallic hardeners are offered for commercial spaces where aesthetics are important, such as retail stores, showrooms, and offices.
With this quality you have achieved both long-lasting durability as well as beauty, providing a welcoming atmosphere while protecting your flooring.
5. SAFETY
Another important characteristic of many dry shake hardeners is the safety improvement achieved in the workplace. Many formulations are formulated to be slip resistant, reducing the potential slip accidents in busy environments.
Additionally, use of a textured finish can be applied to create an even more traction-enhanced surface for safer surface for employees and guests. This focus on safety can lessen workplace injury, and liability.
6. SUSTAINABILITY
Using dry shake hardeners creates a more sustainable approach to concrete flooring. Since dry shake hardeners last a long time, they reduce the frequency of repairs and replacements, which minimizes the total environmental footprint that goes along with maintaining concrete.
It takes fewer materials to maintain the surface over time; less waste, and fewer materials consumed equates to a green approach to dry shake hardened flooring, thus making it a responsible choice related to construction and the management of facilities.
Classification of Dry Shake Hardeners
A dry shake hardener can be classified broadly based on its composition and performance characteristics, which greatly affect their use in different environments:
1. Metallic Dry Shake Hardeners
Constructed with metallic aggregates, mainly iron or steel shot, they provide greater durability. Their extraordinary toughness makes them a perfect fit in industrial environments with high point loads and extreme abrasion.
Industrial settings such as heavy manufacturing plants, warehouses, and transportation terminals are exemplary of when slippery soled shoes could be abused and high wear-and-tear takes place on the surface of a floor. The degree of durability prolongs the life of concrete surfaces.
2. Non-metalic Dry Shake Hardeners
Non-metalic dry shake hardeners are made from mineral or quartz aggregates and are specially designed for corrosion protection, so they can work well in wet environments where moisture may damage different materials.
Non-metallic dry shake hardeners are often used in sensitive environments like food processing environments, retail spaces, pharmaceutical labs, and light manufacturing environments due to hygiene and safety concerns.
3. Colored Dry Shake Hardeners
Colored dry shake hardeners contain numerous colored pigments that allow a wide range of aesthetic options while providing surface protection.
Being able to provide surface protection while also improving aesthetics makes colored hardeners a perfect option for commercial/public spaces such as malls, offices, and parks. In addition to aesthetic value, colored hardeners help improve visibility and safety.
4. Specialty Hardeners
Specialty hardeners can be any product that has been designed using additional combinations of additives to obtain a specific performance requirement.
For instance, a significant chemical resistance, which is important for spills or exposure to chemicals, and/or an anti-slip texture for wet areas or high volume pedestrian areas.
There are also options for fast-setting methods, which can shorten project turnaround time and reduce downtime in operations.
Specialty hardeners would be fitted for environments with specific specialized needs and are common in laboratories, kitchens, or outside exposed areas.
These categories demonstrate just how flexible and specialized dry shake hardeners can be, providing concrete surfaces with the functional and aesthetic characteristics required for a variety of industries.
5. Abrasion Resistance and Durability
The vast majority of the time that dry shake hardeners are used, the goal is to greatly enhance the concrete floor’s overall ability to withstand wear when subjected to high foot traffic.
Abrasion resistance is characterized by the floor’s ability to resist surface wear caused by friction, which is important for protecting the integrity and appearance of the flooring over time.
Given this, dry shake hardeners facilitate abrasion resistance by integrating hard aggregates and specialty cementitious binders in the fresh top surface of the pour.
Dry shake hardeners can comprise a number of materials including, but not limited to, either quartz, carbide, or metalic particles, which enhances the overall durability and utility of the surface.
Metalic hardeners, in comparison to mineral-based hardeners, have the potential to deliver better resistance against abrasion. It is important to anticipate that metallic hardeners may rust if moisture exposure occurs and protective coating is not applied.
For appropriateness of comparison one standardized test is commonly performed on dry shake hardeners. The test, specified as either ASTM C779 (method C, abrasion resistance via a rotary platform) or ASTM D4060 (Taber Abraser testing), provides a means of standardization and a reasonable path to the consideration of dry shake hardeners’ expected service life relative to each other.
Dry shake hardeners are able to provide as much as 300% greater resistance against abrasion than untreated concrete surfaces.
This comparison becomes important for industries in search of flooring solutions with longer service life, including retail spaces, manufacturing plants, and warehouses.
Application Methods and Rates
1. Surface Preparation
Freshly poured concrete should still be wet and level.
Do not apply the hardener to freshly poured concrete if there is any water that is bleeding out or if the set is delayed.
2. Application
Dry Shake Hardeners’
Broadcast dry shake material uniformly across the entire surface. In most cases, the dry shake material can be broadcast in two passes:
First pass with about two thirds of the total amount of dry shake material.
Second pass after the initial set, apply the remaining third of the specified total amount.
3. Troweling & Finishing
Ninety-degree trowel angle creates a denser surface.
Using mechanical power trowels or hand tools incorporate the dry shake hardener into the surface, making several passes, in order to complete the finish and obtain a flat dense surface.
4. Curing
Curing should be done to alleviate shrinkage cracking.
Include curing compounds and wet curing methods to retain moisture.
Application Rates
Depending on type of hardener and anticipated traffic, each may have a different application rate.
metalic floor hardener 6–10kg/m²Non-metalic floor hardener 4–8 kg/m²
Design Guidelines:
Slab Thickness – The thickness of the concrete slab should be determined based on the load bearing requirement for the specific structure, but is typically 4 to 6 inches for residential applications.
Slab thickness must adequately support, or carry, the weight load that may be expected from furniture, equipment, fixtures, or foot traffic.
Reinforcement – It is important to use adequate structural reinforcement, like steel rebar or welded wire mesh, to improve the tensile strength of the concrete slab.
Structural reinforcement should be properly spaced, tied, and expansion joints must be included in the slab at the proper spacing to minimize cracking due to thermal expansion and contraction.
Flatness and Levelness – Before applying any hardeners or finishing treatments to the concrete, it is important to confirm that the surface of the concrete is flat and level.
Use a straightedge or a laser level to check for flatness and level using a 10 – 20 ft long straightedge or a laser level over the surface of the slab.
Any deficiencies in level or flatness should be corrected through grinding the surface or additional levelling in order to achieve a consistent surface which will allow for a more uniform hardener application, and to mitigate future issues.
Environmental Conditions – While hardeners and finishing products are applied to the concrete slab, it is imperative to keep a close watch on environmental conditions. Avoid working during high winds because this will accelerate drying and affect the finish of the slab.
Direct sunlight also causes uneven curing and surface defects, so work should be done where possible during cooler parts of the day, or the use of curing covers should be considered.
When temperatures are close to freezing, they cannot be tolerated as they will impact the curing process and durability of the slab in the future.
Compatibility – When selecting and applying a dry shake hardener, ensure that it is compatible with any other floor treatments or coatings. You may want to conduct tests or consult product companies to verify that the chemical makeup is not chemically incompatible, which could compromise the performance and appearance of the floor in the future. Testing for compatibility is needed to obtain maximum potential with surface treatments.
Conclusion
Dry Shake Hardeners for Concrete Floors provide an intelligent and efficient way to prolong the life of your concrete flooring and improve its performance.
Heavy warehouse floors, commercial retail floors, or clean room manufacturing all benefit from the use of the right dry shake hardener. Whether or not you select a metalic or non-metalic floor hardener is subject to your needs and limitations in your facility.
By increasing durability, decreasing maintenance costs, and providing custom aesthetic choices, dry shake hardeners offer a value proposition that stretches beyond just a floor surface. Proper site conditions and consideration of application, curing, and design are ideal to achieve optimum end results.
In the end, a properly chosen dry shake system will ensure that the concrete floor you install will be aesthetically pleasing, perform well, and be safe for many years.
