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Epoxy Resins for Civil Engineering Applications. What is Civil Engineering ????. Concrete Protection and Repair. Floorings Self-leveling Trowelable Decorative Floorings [ Stone Carpets ]. Concrete Repair Mortars / Grouting Bonding Systems Crack Injection.
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What is Civil Engineering ???? Concrete Protection and Repair • Floorings • Self-leveling • Trowelable • Decorative Floorings [ Stone Carpets ] • Concrete Repair • Mortars / Grouting • Bonding Systems • Crack Injection
Why Protect and Repair Concrete ? • pH of concrete decreases due to acid attack (CO2 , SO2 , acid rain etc.) } • pH decrease Corrosion of steel rebars • Chloride salts (e.g. de-icing) • Water absorptionof concrete Frost Degradation of Concrete
Desired properties Protection and repair of concrete • ambient cure application window • easy to apply • workable pot-life • quick dry to enable to walk on it after 1 day • impact strength • flexural strength • resistance against mechanical stresses • crack bridging properties • ground water protection • chemical resistance • self-leveling and seamless flooring systems
Features of Epoxy resins for CE • adjustable curing speed at RT • low sensitivity to moisture during curing • very good adhesion on concrete and “green-concrete” • very low linear shrinkage and corresponding tension • very good chemical resistance • very high durability BUT • limited weatherability (UV-light)
Typical Flooring Composition • 2 Pack system [ or 3 pack ] Component A Component B Epoxy Resin Curing Agent Pigments Pigments Quartz sand Additives Additives mix prior to use, pot-life of 30 minutes to 2 hours • Ambient Cure
Surface Preparation Surface must be clean and sound. All dirt, laitance, grease, curing compoundsand other foreign matter must be removedby sandblasting, abrasion, or acid etching. Water and dust must be removed from allsurfaces immediately prior to application.
Concrete Inspection and Preparation Crack Bridging Self-leveling Flooring SystemTypical three layer (3 days operation) build-up Impregnation • 300 - 500 g/m2 • viscosity below 500 mPa.s • cover with 1000 g/m2 Quartz-sand 0.2 - 0.7 mm Finishing Layer • 2700 g/mm2 to 2 mm thickness • viscosity below 2000 mPa.s 4 mm Functional Layer • 2700 g/m2 to 2 mm thickness • viscosity below 2000 mPa.s Concrete Substrate
Dow Epoxy resins for Civil Engineering • D.E.R.™ 331™ / D.E.R. 336 Epoxy Resin • Liquid Bisphenol-A based Epoxy Resin • D.E.R. 354 Epoxy Resin • Liquid Bisphenol-F based Epoxy Resin • D.E.R. 352 / D.E.R. 356 Epoxy Resin • Liquid Bisphenol-A/F Epoxy Resin • { to prevent crystallization } • Reactive Diluent Blends { reduced viscosity } D.E.R. 321 / D.E.R. 324 Epoxy Resin • Bisphenol-A type D.E.R. 353 / D.E.R. 358 Epoxy Resin • Bisphenol-A/F type • D.E.R. 671-X75 and 684-EK40 Epoxy Resin Solutions • Primer - Surface Impregnation ™ Trademark of The Dow Chemical Company
Self-leveling Flooring SystemTypical formulation: Binder [ % ] 40 • D.E.R.™324 Liquid Epoxy Resin 25.2 • Quartz-sand [ 0.1 - 0.3 mm ] 35.2 • Quartz-powder [ < 0.06 mm ] 22.5 • Titanium-dioxide [ Color ] 1.7 • Air-release agent 0.4 • e.g. BYK A-525 • Amine - Epoxy Adduct Curing Agent 15.1(e.g. Polypox H 043 ex. UPPC ) {Concrete}Compressive Strength = 50 N/mm2 { 40 }Flexural Strength = 60 N/mm2 { 4 }Tensile Strength = 43 N/mm2 { 2 } STRONGER THAN CONCRETE !!! ™ Trademark of The Dow Chemical Company
Regulatory Trends • ground water protection • secondary containment • VOC reduction and regulation • elimination of aromatic amines • use of safer reactive diluents
Technology Trends • lower temperature cure • curing down to, below, 0 °C • mainly driven by curing agent • lower viscosity { Bisphenol-A/F and RD blends } • 500 - 6000 mPa.s @ 25 °C • aqueous systems • coatings on concrete • polymer concrete • Epoxy Cement Concrete • flexible epoxy resins • 50 - 200 % Elongation • crack-bridging concrete • non crystallizing Resins • stable on filler addition • winter time outside storage stable
End of the Civil Engineering Part !!! Further Technical as well as Product Stewardship related information can be found on www.Dowepoxy.com. e.g. Dow Epoxy Products Portfolio incl. Corresponding technical datasheets, Dow Liquid Epoxy Resin Brochure Dow Epoxy Novolac Brochure Dow Epoxy Resin Product Stewardship Manual Dow Epoxy Curing Agents Product Stewardship Manual