Polymer Concrete and Mortars based on epoxy/silica composites

Polymer concrete may be used for new construction or repairing of old concrete. The adhesive properties of polymer concrete allow repair of both polymer and conventional cement-based concretes. The corrosion resistance and low permeability of polymer concrete allows it to be used in swimming pools, sewer structure applications, drainage channels, electrolytic cells for base metal recovery, and other structures that contain liquids or corrosive chemicals. It is especially suited to the construction and rehabilitation of manholes due to their ability to withstand toxic and corrosive sewer gases and bacteria commonly found in sewer systems. Unlike traditional concrete structures, polymer concrete requires no coating or welding of PVC-protected seams.[4] It can also be used as a bonded wearing course for asphalt pavement, for higher durability and higher strength upon a concrete substrate, and in skate parks, as it is a very smooth surface.[citation needed]

Polymer concrete has historically not been widely adopted due to the high costs and difficulty associated with traditional manufacturing techniques. However, recent progress has led to significant reductions in cost, meaning that the use of polymer concrete is gradually becoming more widespread.

Why Use Epoxy Mortar?

Epoxy mortar is a polymer-based bonding paste that comprises materials such as epoxy resins, solvent, binder, mineral fillers and some additives. The epoxy element is a two-component organic polymer that is blended with sand and, sometimes with coarse aggregate. Epoxy mortar with or without the aggregate will provide an impermeable environment and barrier that will protect reinforcing steel against corrosion. The certain measurements are dependent on the desired properties after curing.

It is used as an adhesive and paste for structural repair. It can also be used to fill gaps, cracks and vents in driveways, patios and plazas. In setting tasks, it is used for tile installation where sealers are not required.

What Are The Benefits Of Epoxy Mortar?

Epoxy Mortar has many benefits and is used in an array of applications.

    High-strength and high-hardness
    Excellent adhesion to many different materials
    Ease of mixing
    Cures quickly
    Strong moisture impermeability
    Stain resistant
    Good abrasion, impact and chemical resistance
    A range of colour mixes available
    Non-sag and non-slip
    Prolongs the life of structures

The premium properties are achieved by the type of formula used to produce the mortar. They are available in parts or components, where the common ones are two-part epoxy-based mortars (hardener and resin). However, it is expensive as compared to cement-mortar, but it provides the desired performance once applied. Different formulas are used by the available brands; therefore, there is no fixed formula for this product. It prolongs the life of structures.

How Does Epoxy Mortar Work?

As the epoxy mortar is in the curing process the exothermic reaction creates a temperature rise that results in expansion. If the mix has fine or coarse aggregate the temperature rise and expansion is minimised. Inevitably the mass will cool and there will be shrinkage as the mass returns to its original size. However, epoxy mortar experiences little or no shrinking during the curing process.

The Difference Between Epoxy Mortar And Cement Mortar

Cement mortar is a mix of fine aggregate (usually sand), a binder (typically lime or cement) and water. It is applied as a thick paste which sets hard as it cures and creates a tight seal between bricks and blocks to prevent air and moisture ingress.

Whereas epoxy mortar uses epoxy resin the blend to form a material that has stronger adhesive properties. Both cement mortar and epoxy mortar have specific applications due to their own characteristics.

When To Use An Epoxy Mortar?

Epoxy mortars can cost as much as eight times that of cement-based mortars. Cement-based mortars are typically easier to work with and are odorless, unlike epoxy mortars. However, despite its cost, effort to apply and odour, epoxy mortar has many great characteristics that make it suitable for certain jobs.

Due to its availability in a variety of colours, its fast curing and stain resistance, epoxy mortar is a popular choice for tile setters. Cement-based mortar can take multiple days to properly set and then must be grouted, whereas epoxy mortar does not require sealing due to its water resistant qualities.

Epoxy Resin Mortars are also the repair mortars normally selected for rapid and high strength concrete repairs. These mixes comprise of at least 2/3 components which are the base epoxy resin, reactive hardener and sand / aggregate fillers. If the mortar is designed for thinner layers or filling and bonding applications the aggregate is more critical in terms of its grading and granulometry, so with these products it is normally supplied premixed with the base resin component.

A Comparison Between Epoxy and Cement Grouts, or Which Product Should We Use?

This question comes up time and time again. Epoxy and cement grouts each have preferred usages in today’s industrial construction and some cases overlapping as well as specific applications. These are distinctly differing systems, with quite different chemistries, and need to be sold and serviced as their individual application dictates. In most cases, recognizing the differences is the key to success or failure of an installation.

In general, epoxy grouts are recommended for:

•    Very high early strength applications resulting in lowest downtime.
•    Chemical and oil resistant and in some cases as a corrosion preventer.
•    Vibration damping.
•    Grouting reciprocating compressors.
•    Applications requiring maximum bond to foundation and machine or baseplate resulting in a monolithic structure.
•    Injection into cracks and deep penetrations for repairs to concrete.
•    Ability to withstand high dynamic loading without failure.

Cement grouts are recommended for:

•    General civil construction, erecting baseplates, grouting precast members or providing bedding mortar, column joints, etc.
•    Anchor bolts cables or rod grouting not requiring sustained high tensile loads.
•    Applications of machinery or equipment with temperature cycling or sustained elevated temperatures over 200°F.

Applications where both epoxy and Portland cement grouts may be used include:

•    Any installation of noncritical rotating equipment or where long-term equipment reliability and operation is not a major concern.
•    Structural elements requiring maximum bearing support.

The following performance characteristics of epoxy and cement grouts listed below are for the purpose of determining the use of the most suitable product for an intended use. One property or requirement of a grout is seldom the only determining use, two or more properties are generally considered before selecting a product. The grout requirements for each use should be determined by the importance of the installation and overall suitability:

1. Compressive strength

        High early strength: For ambient temperature conditions of 70°F epoxy grout can be expected to be superior to cement products. Most epoxy grouts will produce 8,000–10,000 psi within 24 h as compared to most cement grouts producing only 3,500–4,000 psi @ 24 h.

        Ultimate: Epoxy grout produces 12,000–15,000 psi @ 7 days (standard maximum curing time) as opposed to cement grouts producing 5,000–7,000 psi @ 7 days and 8,000–10,000 after 28 days of proper curing.

        Conclusion: Both types of product produce higher ultimate compressive strength than required for typical construction grouting purposes. For high early strengths, epoxies have a commanding edge in strength gain at 70°F.

2. Lowest “downtime” (maintenance)

        As epoxy grouts produce very high early strengths their use may result in less production “downtime” for machinery in regrouting maintenance.

        Hydraulic cement grouts may be utilized providing less downtime if warm product and/or external heat is applied, and the same may be said for epoxy products under cool conditions. Unfortunately, cement grouts will not develop a good bond to steel.

        CONCLUSION: On the basis of strength alone, epoxy grout has a distinct advantage over Portland cement grouts.

3. Chemical resistance

        There is no cement grout which will compete with epoxy for chemical resistance. Epoxy grouts are especially effective in applications that require resistance to dilute acids. Exposed cement grouts may be coated for protection with epoxies or epoxy mortars, their effectiveness dependent on whether cracks develop in the coating exposing the substrate.

4. Volume change

        Epoxy grouts indicate small amounts of shrinkage during cure. Expect approximately 90–95% plate bearing contact with epoxy grout. This figure is attributed essentially to entrapped air which rises to the interface of the grout and underside of the baseplate. This is accepted as normal and acceptable within industry.

        Epoxy grout does not suffer drying shrinkage as such, but there is some chemical shrinkage when curing takes place. This is usually 0.5–1% of the total volume of the grout pour. This change in volume occurs in the pour or unrestrained areas.

        Because of its high vibration damping characteristics and strength experience has shown that for many epoxy grouts as little as 75% contact has provided long-term service for most applications.

        Portland cement grouts. Most cement grouts are designed to perform in accordance with The Corps of Engineers Specification For Nonshrink Grouts (CRD-C 621), and as a consequence must increase in volume in the hardened state when unconfined or go into compression when confined. In some critical alignment installations, this compression could result in loss of alignment by baseplate deformation.

        CONCLUSION: Nonshrink cement grouts should conform to specification CRD-C 621. Epoxy grout should be used for applications requiring corrosion resistance, high early strength and a bond to concrete stronger than the concrete tensile strength.

5. Creep

        Epoxy grouts are formulated to be highly creep resistant when tested in accordance with ASTM C-1181. Epoxy grouts are not as rigid as Portland cement grouting products. Load, temperature, and application must enter into this portion of the decision-making process. Do not base your decision solely by looking at published figures on creep testing.

6. Thermal coefficient of expansion (COTE)

        The thermal coefficient of expansion of epoxy grouts will vary with composition of the product. This figure should closely match that of concrete and steel. The lowest reported COTE reported and verified so far is 11.2 × 10−6 in./in./°F.

        The thermal coefficient of expansion for Portland cement grouts will be approximately 5.5 × 10−6 in./in./°F.

        Where epoxies are used with concrete (or steel) the difference in COTE should be recognized and accommodated for with expansion joints and other techniques outlined in this book. This difference in COTE poses no grout problem.

7. Toughness

        Epoxy grouts exhibit greater durability, strength, and overall toughness than cement grouts.

8. In-place costs—jobsite

        The costs of materials, foundation, plate and forming preparations, mixing and placing are considerably higher for epoxy grouting than for cement grouts. Cleanliness and foundation moisture is more critical to the proper application of epoxy grout than for Portland cement grouting products. The long-term equipment reliability resulting from use of epoxy grouts are worth the extra effort and cost.

9. Damping

        The term “damping” refers to the energy absorbing capacity in cyclic loading such as vibration and pounding. Epoxy grouts offer excellent “damping” characteristics superior to that of cement grout products.

10. Modulus of elasticity

        The modulus of elasticity for epoxy grouts is in the magnitude of 1.5–2.5 million pounds. Epoxies can be formulated to affect a range from 0.5 to 4.5 million.

        Cement grout can have a modulus of elasticity of 4.5 million at the 10,000 psi compressive strength level. This is dependent on how much water is applied when it is mixed and how it is cured.

11. Ranges of temperature limitations

        Epoxy grout should not be placed when grout and foundation temperature cannot be maintained above 55°F or more and care must be exercised with placement at elevated temperatures. Epoxy grouts are not normally recommended for applications where ambient or operating temperatures exceed 180°F. Special formulations will withstand temperatures up to 250°F but tend to be extremely brittle and prone to crack.

        Portland cement-type grouts may be placed as low as 40°F and with a recommended upper placing limit of 100°F, using due care particularly at lower limits. They may be utilized in working environments after thorough curing and then drying up to 400°F.

12. Thickness limitations

        Some epoxy grouts can be poured in extremely large areas up to 7 ft × 7 ft × 18 in. in depth. This results in epoxy being used as a foundation reconstruction material to reduce downtime on regrouts.

        Cement grouts may be placed in lifts at any thickness up to 12 in., or more, when foundation, bolts, rebar, and plates act as heat sinks.

13. Shipping and storing

        Most epoxy products are not affected by freezing during shipping or storage. Prior to application at a jobsite the material should be preconditioned to ensure proper blending and thermal reaction of the resin and hardener. Environmental control should be used to keep the epoxy grout within a moderate temperature range during its placement and cure.

        Cement grouts like epoxy are not affected by freezing temperatures. A recommended mixing and placing temperatures of 40–100°F without preconditioning or environmental control can be observed.

14. Curing

        Epoxy grouts require no curing media other than a temperature above 55°F.

        Cement grouts require early application of clean water saturated rags on exposed surfaces for 5 or more hours, followed by a curing compound application.

CONCLUSION: The performance characteristics of epoxy and cement grouts listed above are for the purpose of determining the use of the most suitable product. One property or requirement of a grout is seldom the only determining factor; you should consider two or more properties before selecting a product. The grout requirements for each use should be determined by the importance of the installation and overall suitability.

A three-part high strength epoxy putty suitable for placing using hand tools.
Specially graded fillers allow application thicknesses of 25mm down to a feather edge.

Epoxy Putty is easy to place using hand tools giving concrete bedding and repairs of the highest mechanical properties. The mortar can be used to give support to concrete arises and will act as a high strength support under precast concrete and steel units. Epoxy Putty is resistant to a wide range of chemicals including petroleum products. The mortar is stable to freeze-thaw action. Typical uses include repair of concrete beams, columns, walls and floors in areas where a smooth finish is required. Also for bedding applications to support precast concrete units, steel stanchions, wooden blocks and baulks, anti-vibration units and in other areas where strength of the highest order is required.

Once mixed, the putty can be easily moulded to form permanent watertight repairs with a smooth finish to concrete, brick, mortar and plaster. It adheres well to wet surfaces and is suitable for most underwater repairs. In cured form it is many times harder and more impact resistant than concrete, has a similar consistency and colour to new concrete, and has excellent chemical and UV resistance.

Features & Benefits

• Permanent watertight repairs – Concrete, brick, mortar and plaster
• Fast Cure – Cures hard within 3 hours at 30ºC.
• Permanent and super strong – Cures harder and more impact resistant than concrete.
• Excellent cohesive properties in uncured state – Easy to work and mould, ideal when a smooth even finish is required.

The product is also used for the coating of surfaces (increases bonding strength and durability) before the application of polymer MORTARS with larger grain size between 0.4-1.2mm  on walls, stairs or other inclined concrete and stucco surfaces. Its use is especially necessary for gain sizes of 2mm and above. Seals capillary cracks, but also larger gaps on concrete surfaces, without shrinking, cracking, or sagging when applied on vertical surfaces. Classified as structural bonding product to concrete.

Terrazzo consists of chips of marble, granite, glass, and other substances decoratively set in either cement or epoxy. It is polished until smooth to display ornate decorative patterns of colored specks. 

Terrazzo has evolved as new technologies emerge. The modern epoxy resin system transformed elements of design and installation, and broadened the applications. Terrazzo’s versatility brought designers to treat a floor area as a blank canvas providing the freedom to create unique color schemes and designs.

What is Cementitious Terrazzo?

Cementitious terrazzo flooring is the setting of the aggregates in cement. In comparison with epoxy terrazzo flooring, cementitious terrazzo is considerably thicker and heavier making it the ideal choice in some applications.

Cementitious terrazzo flooring offers a wide range of elaborate designs that feature various color schemes and Earth tones. This type of terrazzo is significantly thicker and can withstand considerable impact. 

Cementitious terrazzo is durable and resilient, lasting many years with minimal maintenance. 

Pros

• Cementitious terrazzo is suitable for both indoor and outdoor applications and will thrive in extreme UV-ray exposure.

Cons

• Cementitious terrazzo offers a broad color palette, but the colors are not as vibrant as epoxy terrazzo.
• Cementitious terrazzo can take longer to cure, around 28 days.
• Cement terrazzo can crack or chip over time.
• The installation of a cementitious terrazzo system requires a professional.

What is Epoxy Terrazzo?

Epoxy terrazzo is composed of a mix of epoxy and aggregates bound in a thin-set system. An unlimited array of colors along with shimmering pieces of glass, marble, or granite combine to a luxurious and smooth finish. The unlimited range of colors and intricate patterns provides infinite design capabilities.   

Epoxy terrazzo has the advantage of speed of curing. You can expect the curing process to finish overnight. Polishing can be performed the very next day, accelerating the turnaround time of any project. For this reason alone, many commercial and institutional establishments choose epoxy terrazzo.

Pros

• Epoxy terrazzo systems do not require constant maintenance.
• Under most ambient conditions, curing epoxy terrazzo can be finished overnight, and ready to be polished the following day.
• Epoxy terrazzo offers a glossy and non-porous finish.
• Epoxy terrazzo is less likely to encounter fine-line cracking or chipping over time.
• You have unlimited color scheme choices making it easier to experiment with unique patterns and designs.

Cons

• Moisture vapor transmissions can damage the surface area of epoxy terrazzo if it is not designed to be breathable.
• Epoxy terrazzo is not recommended for outdoor applications without additional PU layer, as excessive direct exposure to UV can damage epoxy terrazzo surfaces.
• Epoxy terrazzo system requires professional installation.

Both cementitious and epoxy terrazzo are practical, affordable flooring solutions offering striking visuals to commercial, institutional and residential spaces. Durable and low-maintenance, terrazzo lends timeless elegance to any space. 

A multi purpose, natural brick finish, interior and exterior filler.  Specially formulated to help you re-create the natural appearance of bricks.

• Quick & Easy Brick Repairs - ready mixed formula for cracks, chips, drill holes and other damage
• Virtually Invisible Repairs - available in 11 common brick colours
• Looks & feels like natural brick
• Save Money - significantly cheaper than removing & replacing bricks
• Long Lasting Repair - weather resistant, hard wearing & UV stable
• Professional Finish - used by professional hard surface repair technicians

Repairing damaged bricks is much more cost effective than replacing them. Brick Repair Filler is the quick and simply way of improving the appearance of damaged brickwork.

Bricks vary in colour and usually have a mixture of colours throughout the brick face. Adding multiple colours to the repair can help you create a more natural brick finish to the damaged area.

Rekomenduojami pažintiniai video:

• https://youtu.be/7yDJFIf6QDs
• https://youtu.be/VNR5HtExORA
• https://www.youtube.com/watch?v=vqtJr0jAquM
• https://www.youtube.com/watch?v=-ybnHb5DhLU&t=3s