Facility Maintenance Division of Kukje Chemical & Construction Co., Ltd.
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Facility Maintenance Division of Kukje Chemical & Construction Co., Ltd.

CFMC(Cocos Fiber Mortar Composition) Method

Cocos Fiber Mortar Composition

Eco-friendly mortar composites for repair of concrete structures added with cocos fiber & Method for repair of concrete structures using such mortar composites (Patent no. 10-1691845)

1. Overview of CFMC Method

This method involves the use of eco-friendly mortar and surface protective materials with excellent tensile force and durability, applying the cocos fiber. As the cocos fiber absorbs water and holds more ‘bound water’ necessary for hardening of mortar, compared to other existing mortar, it contains functional admixing agent increasing the durability and provides excellent adhesion, acid resistance, salt resistance, heat resistance and durability. Additionally, it represents an eco-friendly mortar method applying environment-friendly materials as it contains the phyllite, a natural mineral with self-healing properties that fill the cracks while densifying the inner structure of concrete by pozzolan reaction.

2. Advantages of the Method

1) It applies eco-friendly material that contains cocos fiber and phyllite with self-healing properties.
2) The actions of active silica and aluminate components create long-term properties and increase chemical resistance such as acid resistance, alkali resistance, and salt resistance.
3) Containing natural pozzolan material and latent hydraulic materials, it is a repair material that increases the long-term strength and durability of concrete.
4) It applies the mortar which has higher strength, compared to other methods.
5) The cocos fiber absorbs water, preventing evaporation of surface moisture, and is highly effective in suppressing the crack caused by dry shrinkage.
6) It has excellent moisture resistance and water absorption coefficient, providing excellent air permeability.
7) Using the mortar with excellent durability, it provides anti-rust effect, salt resistance, anti-neutralization effect, eliminating related concerns fundamentally.
8) The actions of inorganic thickening agent help prevent separation of materials, reduce the loss of materials, and improve the workability and paintability.
9) As the strength can be achieved early, the construction time can be shortened.
10) As the One Packaged type repair material, it improves the workability at the site.
11) It is cost-effective, compared to other methods.

3. Characteristics of Material

Performance of eco-friendly cocos fiber mortar(CFMC-M)

Item name Unit Mortar(CFMC-M) Based on KS F 4042
(Polymer cement mortar for repair of concrete structure)
Flexural strength N/㎟ 8.0 or higher 6.0 or higher
Compressive strength N/㎟ 40.0 or higher 20.0 or higher
Adhesive force N/㎟ 1.5 or higher 1.0 or higher
Chloride ion infiltration resistance Coulombs 800 or less 1,000 or less

Features and advantages of eco-friendly cocos fiber mortar(CFMC-M) material

Self-healing mechanism

The active silica(SiO2) of mortar and calcium hydroxide (Ca(OH)2) separated by hydration of cement react with each other to create insoluble calcium silicate (CaSiO3) in a pozzolan reaction, densifying the inner structure of concrete and filling the cracks.

  • 1. Occurrence of cracks

  • 2. Filling the cracks

  • 3. Recurrence of cracks

  • 4. Re-filling the cracks

- Mimetic diagram of self-healing features -

  • Testpiece before self-healing

  • Testpiece after self-healing

Performance of eco-friendly coating agent(CFMC-C) material

Item name Unit Coating agent (CFMC-C) Based on KS F 4936
(paint film material for protection of concrete)
Permeability resistance - No abnormality Permeation not allowed
Adhesive force N/㎟ 1.5 or higher 1.0 or higher
Appearance after paint film formation - No abnormality No wrinkle and fine crack are allowed

Features and advantages of eco-friendly coating agent(CFMC-C)

The eco-friendly protective finishing material is the self crosslink structured acryl emulsion formed by coating such acryl emulsion onto the fine particle hollow silica. It is a fine particle with a diameter equal to approximately 1/10 of that of existing emulsion. The ultra-fine particle hollow silica is densely and regularly distributed to the nano layer in the paint film and formed into interpenetrating polymer network(IPN) structure which is continuously combined with polymer layer. It is an eco-friendly aquatic surface-protecting agent very similar to the inorganic protecting agent. In addition, it is free from surface stains, etc., caused by entanglement of inorganic components and provides excellent workability and constructability, high adhesive strength, high durability, and particularly, excellent water resistance, and ultraviolet ray(UV) resistance.

Effects from application of eco-friendly mortar(CFMC-M) and environment-friendly coating agent(CFMC-C)

During the hydration reaction of eco-friendly mortar with cement, the cross section, created by pozzolan reaction, can be finished with environment-friendly coating agent to block external contaminants, such as carbon dioxide(CO2), moisture, salt, etc., so as to form a paint film with minute air permeability and make the surface pores more dense effectively, achieving color stability and higher chemical durability.

This eco-friendly surface coating agent consists of hollow silica with particle size in the range from 1㎛ to 60㎛(micrometer), metal compounds, and self-crosslink structured acryl emulsion, forming a dense shielding film and creating adhesive layer on the surface of structure to ensure water repellency and protection of surface of structure from external corrosive elements, ultimately increasing the durability.

4. Applications of CFMC Method

Restoration, repair, reinforcement of sewage culvert cross section loss and cross section of corroded part in rebar

Cross section loss of architectural structures/civil engineering structures & restoration, repair, reinforcement of cross section of corroded part in rebar

5. Sequence and detail drawing of CFMC Method application

Sequence of works - Repair of cross section

    • Surface treatment and chipping

    • water jet cleaning

    • Primer(CFMC-P) coating

    • Eco-friendly mortar(CFMC-M) coating

    • Coating agent(CFMC-C) application

Sequence of works - Repair of cross section

    • Surface treatment and chipping

    • Elimination of rust from rebar

    • water jet cleaning

    • Application of anti-rust agent for rebar(CFMC-R)

    • Primer(CFMC-P) coating

    • Eco-friendly mortar(CFMC-M) application

    • Coating agent(CFMC-C) application

Photo showing the process

6. Certificate of patent