Facility Maintenance Division of Kukje Chemical & Construction Co., Ltd.
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)
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.
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.
Item name | Unit | Mortar(CFMC-M) |
Based on KS F 4042 (Polymer cement mortar for repair of concrete structure) |
Remarks |
---|---|---|---|---|
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 |
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
Testpiece before self-healing
Testpiece after self-healing
Item name | Unit | Coating agent (CFMC-C) |
Based on KS F 4936 (paint film material for protection of concrete) |
Remarks |
---|---|---|---|---|
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 |
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.
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.
Sewage culvert cross section loss
Sewage culvert rebar corrosion
Ordinary architectural structures
Lower part of bridge(elevated bridge)
Subway tunnel of civil engineering structures
Cross section loss of subway tunnel
Surface treatment and chipping
water jet cleaning
Primer(CFMC-P) coating
Eco-friendly mortar(CFMC-M) coating
Coating agent(CFMC-C) application
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
1. Surface treatment and chipping
2. Removal of rust from rebar
3. Application of anti-rust agent for rebar
4. Primer coating
5. Mortar application
6. Coating agent application and completion