A COMPLETE RANGE OF CONCRETE ADMIXTURES
For more than a century, Sika has been producing high quality, innovative admixture technologies for concrete. Sika’s first product, appropriately named "Sika 1", was a concrete admixture that allowed for the electrification of tunnels in Europe by waterproofing the concrete that lined the interior. Now recognized as a world leader in specialty chemicals and other products specifically engineered for concrete, we continue to bring technologies to the market that focus on the optimization of cost, workability, and durability of concrete throughout the production and placement processes.
With a full line of concrete admixtures and complementary products for ready mix, tunneling & mining, precast/prestress, paving, manufactured concrete products, and dry mortar production, Sika has unique and innovative solutions to meet the needs of the concrete industry. Our broad range of admixtures help to improve both the plastic and hardened properties of concrete, providing both consistent and reliable results to our customers and end users.
SikaFiber offers a complete line of fiber solutions to deliver stronger, reliable reinforced concrete to the jobsite. Sika is the expert in concrete fibers.
SikaFiber & Fibermesh Product Technology
Fibers are an ideal ingredient for use in concrete and mortars as a method for improving these materials where they may otherwise have weaknesses. Concrete fibers reduce shrinkage crack formation and crack widths whilst also increasing performance in energy absorption and fire resistance. Additional benefits such as reduction or elimination of reinforcing steel and increased durability can also be seen. Applications with concrete fibers have expanded and new fiber materials are also increasingly capable of replacing traditional fibers such as steel and glass.
In 2018, Sika® has acquired the global Concrete Fibers business from Propex Holding, LLC, which includes a US plant manufacturing synthetic fibers for use in concrete reinforcement, sales operations across Sika’s geographical regions, and Fibermesh® a strong brand in FRC. The acquired business was the perfect addition to Sika’s concrete admixture product lines making Sika® a true single source supplier for all ready mix and precast concrete applications. With the addition of Fibermesh®,Novomesh®, Novocan®, and Enduro® to Sika’s product portfolio, Sika® can better supply the needs of concrete customers, engineers, general contractors, owners, and architects.
KEY FRC BENEFITS
- Reduced incidence of early age plastic shrinkage cracking
- Improved load capacity and ductility
- Protection against freeze-thaw cycles
- Better cohesion in the fresh concrete
- Increased abrasion resistance
- Higher flexural and shear strengths
- Reinforcement replacement
- Joint Extension
Concrete fibers have an innumerable amount of applications in concrete construction. Not only will benefits in fresh and hardened properties be seen, secondary benefits will be made as well. By reducing or replacing traditional meshes and steel reinforcement, labor costs will be reduced and construction schedules can be accelerated. Safety is increased by reducing the chances of tripping or impalement by traditional steel reinforcement. With concrete fiber being integral (well mixed) throughout the concrete, there is no opportunity for reinforcement to end up in the bottom of your slab.
Key Application Benefits
- Integral Reinforcement
- Increased safety
- Less opportunities for callbacks
- Long term durability increase
- Reduction in labor for placement of reinforcement
The first step to choosing the right fiber is to understand the type of fiber required for your application. The main standards for fiber reinforced concrete are ASTM C 116 and EN14889. ASTM C 116, Standard Specification for Fiber Reinforced Concrete, outlines four (4) classifications for fiber reinforced concrete:
- Type I - Steel fiber-reinforced concrete or shotcrete (ASTM A820)
- Type II - Glass fiber-reinforced concrete or shotcrete (ASTM C1666)
- Type III - Synthetic fiber-reinforced concrete or shotcrete (ASTM D7508)
- Type IV - Natural fiber-reinforced concrete or shotcrete (ASTM D7357)
Micro fibers have a diameter that is less than 0.3 mm. Micro fibers are either monofilament or fibrillated. Micro fibers should be used for plastic shrinkage control (cracking that can occur in the first 24 hours of concrete cure), impact protection, and reduction of explosive spalling during a fire. The fibrillated micro fibers are often used in replacement of the lightest welded wire fiber (6x6 W1.4/W1.4) for temperature and shrinkage characteristics.
Structural macro fibers have a diameter greater than 0.3 mm. Macro fiber are used as a replacement for temperature and shrinkage reinforcement (WWF) or as structural reinforcement in concrete or shotcrete. Macro fibers are used where an increase in residual (post-cracking) flexural strength is required (ASTM C1609 or EN14845).
Steel fibers may be collated (glued) together in a clip. The collation of the fibers does not improve performance of the fiber reinforced concrete. Collated fibers improve the ease of mixing of high aspect ratio fibers. Collated fibers are added to the concrete mix, the bundles are spread throughout the concrete. Continued mixing action breaks apart the clips to let the individual fibers separate quickly throughout the mix.
Fiber performance is influenced by three characteristics; tensile strength, aspect ratio (calculated as the length/diameter) and anchorage (hooked, crimp, emboss, fibrillation, etc.). One characteristic does not outweigh another; all three items have to work together for optimal performance.
Fiber reinforced concrete is a composite material and therefore, all fibers are tested in the concrete to prove their performance.
Fibers begin to function in a structural supportive manner when the concrete matrix starts to crack, just like traditional reinforcement. The crack has to occur for the load to switch from the concrete to the reinforcement. The fibers then provide ductility and support by bridging cracks and thus providing post crack strength to the concrete.
BEST USE OF THE DIFFERENT TYPES OF FIBER
|State of concrete or mortar||Effect/property improvement||Recommended fiber type|
|Fresh||Reduce Rebound of Shotcrete||Micro-PP fibers|
|Fresh||Homogeneity improvement||Micro-PP fibers|
|Up to 24 Hours||Early-age cracking reduction||Micro-PP fibers|
|28 days hardening or more||Improvement of fire-resistance||Micro-PP fibers|
|1-2 days||Reduction of cracks induced by restraint or temperature||Micro & Macro-PP fibers|
|28 days hardening or more||Transmission of external forces||Macro-PP & Steel fibers|
Air entrainment in concrete is a necessity for any areas which will experience cycles of freezing and thawing. By adding in consistently sized and spaced air bubbles at the correct percentage, durability of concrete is dramatically improved. Sika’s line of air entraining admixtures comply with the standards set forth in ASTM C260.
Rebar is utilized in concrete to provide it tensile strength, however, if not properly protected this rebar can corrode and cause concrete to crack and break apart. Sika CNI and Ferroguard technologies can help protect this from happening.
Concrete shrinks! Over time through chemical and drying shrinkage concrete changes volume and these volume changes can cause it to crack. The use of Sika Control SRA’s can help prevent cracking and reduce shrinkage.
Shrinkage cracks in concrete can be caused due to multiple reasons, and there are multiple ways to stop them. The effectiveness of Sika's SRCA's in reducing cracks and compensating shrinkage is achieved by combining the technologies of expansive components and pore water surface tension reduction.
Silica fume is an extremely fine powder that when utilized in concrete can help provide high strengths. SikaCrete products help densify concrete making it more resistant to mechanical abrasion and chemical ingress.
Metakaolin is highly reactive calcined clay. It is amorphous; meaning it chemically reacts with the hydration products of concrete to reduce its permeability and improve its strength and durability.
ASR has been found to be responsible for the deterioration of various concrete structures including pavements, bridges, dams and other structures. The main reason for the occurrence of ASR is the presence of moderate to highly reactive aggregates and the utilization of high-alkali cements which are present in some regions. As a result, concrete for new construction in regions where ASR has been detected require the use of a mitigation alternative to help prevent ASR. Lithium nitrate admixtures are one of most effective mitigation options to prevent ASR.
Sika has a full range of chloride and non-chloride accelerators known as SikaSet that decrease the set time of concrete.
Strength / Hardening Accelerating Admixtures help to increase the early strength of concrete without affecting initial workability. This product type is especially useful in applications for repair, Department of Transportation, and precast concrete applications without the need for changes in cement. Sika® Rapid Series meets the requirements of ASTM C-494, Type C accelerating admixture.
Sika Plastiment series extends the setting time of concrete allowing time for proper placement and finishing without cold joints.
Hydration controlling admixtures control the hydration rate of cement, rather than just delaying set time. In doing so, set times are significantly more predictable, dosing is more consistent, and concrete durability is unaffected. For applications ranging from underground tunneling and mining to managing the effects of long delivery times and heat, hydration controlling admixtures are a versatile solution to control concrete during its plastic state. SikaTard® Series of admixtures meets the requirements of ASTM C-494, Type B and Type D admixture.
The Sika Sigunit line of shotcrete accelerators are high performing products for both the dry and wet spraying process. They provide a distinct reduction in rebound and facilitate overhead spraying.
Concrete placement characteristics are a function of the design and proportioning of cement paste, aggregates, and chemical admixtures. During scenarios such as pumping or placement underwater, the paste viscosity is an especially critical performance factor. The use of a viscosity modifying admixture (VMA) increases the cohesiveness of concrete, thereby reducing the risk of segregation.
Sika’s Viscoscity Modifying Admixtures meet relevant industry standards per application, such as ASTM C-494, Type S or CRD-C661-06. See product data sheets for details.
The appearance of an exposed concrete surface is ultimately how concrete is judged, regardless of quality. Whether removing the appearance of unsightly bugholes, using surface retarder to create an exposed aggregate appearance, or curing concrete for maximum quality, Sika has the right products to enhance final concrete surface.
Flowable fill is a self-compacting, flowable concrete used as an economical fill or backfill material. Available as a powder or liquid, Sika Lightcrete products are an easy and economical solution for flowable fill production.
Sika’s Plastocrete line of water reducers provides an economical and effective way to reduce mix water, providing up to 10% water reduction.
The SikaPlast & Sikament line of products provide superior finishability and water reduction levels of up to 15%.
ViscoCrete products provide outstanding water reduction properties providing up to 45% water reduction. Enjoy consistency in plastic & hardened properties with products that exceed expectations.
What better than the ViscoCrete products that you know and love in a powder form!