1. Presented by: W. R. MEADOWSPresented by: W. R. MEADOWS CEMENTITIOUS WATERPROOFING

2. This program is registered with the AIA/CES for continuing professional education. As such, it does not include content that may be deemed or construed to be an approval or endorsement by the AIA of any material of construction or any method or manner of handling, using, distributing, or dealing in any material or product. Questions related to specific materials, methods, and services will be addressed at the conclusion of this presentation. Thank you! 3. ObjectivesObjectives Explain some of the issues relating to concrete deterioration as a result of water penetration Differentiate between dampproofing, waterproofing and vaporproofing methods Differentiate between positive and negative side waterproofing Identify the various types of cementitious waterproofing systems and differentiate between them 4. Description of ConcreteDescription of Concrete What is concrete ? Origin of concrete ? Composition of concrete Advantages - low cost, high stiffness, high compressive strength, non- flammable, and ease of fabrication Disadvantages - low tensile strength, brittle, that can affect long term durability 5. Chemistry of ConcreteChemistry of Concrete Hydration Formation of: Calcium Silicate Hydrate Calcium Hydroxide Calcium Aluminate Hydrate Calcium Ferrite Water / Cement Ratio determines concrete strength Water - also affects the workability and consistency of the concrete mix. 6. Limitations of ConcreteLimitations of Concrete Although very durable, concrete will eventually deteriorate from natural weathering Degree of deterioration dependent on: - exposure to moisture, temperature, aggressive chemicals - inadequate mix design and materials selection - inadequate design for deterioration - poor construction practices 7. Inadequate Mix Design andInadequate Mix Design and Materials SelectionMaterials Selection Excessive water in the concrete mix leading to excessive bleeding - weakened concrete surface - finishing problems - pitting problems Poor material selection -Pop-outs due to expansion of porous aggregates -Alkali aggregate reaction -ASR (alkali silica reactivity) -ACR (alkali carbonate reactivity) 8. Inadequate Design for DurabilityInadequate Design for Durability Sulfate attack Corrosion of Reinforcing Steel Carbonation 9. Inadequate Design for DurabilityInadequate Design for Durability Chlorides Inadequate accommodation for movement during thermal changes Inadequate accommodation for shrinkage Inadequate design for differential settlement Inadequate design for structural capacity 10. Poor Construction PracticesPoor Construction Practices Minor Defects Major Defects Inadequate cover Cracking Inadequate Protection of concrete Air Entrainment 11. The major deterioration factors listed above can be traced back to the presence of water in the structure. To protect the structure, it is necessary to waterproof it to reduce the potential for this concrete deterioration Even good concrete can be described as permeable and porous 12. What determines the extent of waterWhat determines the extent of water penetrationpenetration Porosity Ratio of the volume of openings (voids) to the total volume of material Most important factor is the water/cement ratio of the concrete Greater w/c ratio, greater porosity 13. Permeability A measure of the ease with which fluids will flow though a material Cracks in concrete interconnect flow paths and increase concrete permeability Increase in concrete permeability due to the progression of cracks allows more water or aggressive chemical ions to penetrate into the concrete, facilitating deterioration The lesser the permeability, more durable the concrete What determines the extent of waterWhat determines the extent of water penetration ?penetration ? 14. PermeabilityPermeability Deterioration includes: Vulnerable to attack of water, chemicals, sulfates, etc. Corrosion of steel reinforcement Increase in potential of freeze/thaw damage 15. What affects permeability ?What affects permeability ? Trapped air pockets from inadequate compaction Empty space due to lack of mixing water by evaporation Age of the concrete 16. How does moisture enter theHow does moisture enter the structure ?structure ? Liquid water Water vapor 17. It is important to understand the difference between water and water vapor when coating concrete 18. How Does Moisture Enter ?How Does Moisture Enter ? Liquid Water Water table Site drainage Irrigation - sprinkler systems Cracks Improper waterproofing details 19. Pressure exerted by a fluid at equilibrium at a given point within the fluid, due to the force of gravity. Increases in proportion to depth measured from the surface because of the increasing weight of fluid exerting downward force from above. Hydrostatic PressureHydrostatic Pressure 20. CapillarityCapillarity The force that results from greater adhesion of a liquid (water) to a solid surface than internal cohesion of the liquid itself and is therefore able to literally rise along vertical surfaces Liquid rises against gravity Smaller diameter, greater rise 21. Diagram showing capillary rise 22. How Does Moisture Enter ?How Does Moisture Enter ? Water Vapor Dependent on differences in temperature and relative humidity Below grade the diffusion of water vapor is from the ground into the structureambient conditions in the ground are approximately 55 degrees F and 100% RH Since concrete isnt a good vapor barrier, water vapor readily passes through the concrete 23. WaterproofingWaterproofing Waterproofing is defined as the resistance of the passage of water under hydrostatic head pressure. 24. DampproofingDampproofing Dampproofing is defined as the resistance of water in the absence of hydrostatic head pressure. Dampproofing materials typically will not bridge cracks in concrete that may occur during the life of a building. 25. A vaporproofing material is one that reduces the passage of a gas under pressure. Vapor diffusion can be defined as the transmission of water vapor, independent of air pressure, as a result of a difference in vapour pressure Vapor barriers are materials used, both above and below grade, to retard the diffusion of vapor into and through the building enclosure system. It is important to understand this when it comes to application of waterproofing coatings and their vapor permeance. Avoid low vapor permeable materials on the negative side VaporproofingVaporproofing 26. Characteristics of a WaterproofingCharacteristics of a Waterproofing SystemSystem Effective against moisture intrusion waterproofing, dampproofing, and capillary action Continuous Durable both during and after construction Robust and durable over life of the building 27. Sheet membrane waterproofing Fluid applied membranes Cementitious waterproofing Flexible cementitious coatings Protection boards Composite drainage boards Positive Side WaterproofingPositive Side Waterproofing SystemsSystems 28. Cementitious waterproofing Flexible cementitious coatings Negative Side WaterproofingNegative Side Waterproofing SystemsSystems 29. Consists of Crystalline Waterproofing Flexible Cementitious Waterproofing Cementitious WaterproofingCementitious Waterproofing 30. Material consist of cement, silica and proprietary chemicals Forms a crystalline structure in the presence of water and plugs pores, capillaries, micro-cracks and other voids Becomes integral with the concrete Questions arise due to crack waterproofing Can be surface-applied, added directly to the mix, or sprinkled on fresh slab Crystalline WaterproofingCrystalline Waterproofing 31. Waterproofing of foundations, slabs and walls Water storage tanks in municipal & industrial waste water Potable water tanks & facilities Elevator shafts Parking garages Basements Secondary containment structures Swimming pools Uses of Crystalline WaterproofingUses of Crystalline Waterproofing 32. Free space capillary, micro-cracks in Hydrated cement past Free space filled with dendritic (needle-like) structures 33. Crystalline waterproofing impermeability testing Slovak Technical University (original and translation) 34. Crystalline waterproofing impermeability testing Slovak Technical University (original and translation) 35. Crystalline waterproofing impermeability testing Slovak Technical University (original and translation) 36. Samples Tested after 14 days Penetration (mm) Tested after 28 days Penetration (mm) Tested after 90 days Penetration (mm) Tested after 180 days Penetration (mm) A1 60.0 48.0 21.0 10 A2 58.0 57.67 45.0 46.67 22.0 21.33 7 9.0 A3 55.0 47.0 21.3 10 B1 - 40.0 10.0 4 B2 - 37.0 38.67 11.0 10.33 3 3.67 B3 - 39.0 10.0 4 C1 48.0 38.0 2.0 0.3 C2 56.0 40.0 38.33 1.0 1.33 0.4 0.33 C3 54.0 37.0 1.0 0.3 Independent testing of crystalline waterproofing admixture Testing of concrete hydraulic permeability Testing Laboratory of Civil Engineering Faculty of the Slovak Technical University, Bratislava, Slovakia October 2005 May 2006 A- 0% control; concreteA- 0% control; concrete w/cw/c ratio 0.57ratio 0.57 B- 1.5%;B- 1.5%; C- 2%C- 2% 37. Surface preparation Sound concrete surface Thorough cleaning, high pressure water Treatment of inside corners Patching and joint / crack treatment Saturated, surface dry condition Crystalline WaterproofingCrystalline Waterproofing 38. Crystalline waterproofing - crack, construction joint treatment Wall construction joint treatment, negative or positive side Figure 1a. Construction Joint Treatment Using reinforcing fabric and flexible cementitious coating vertical wall horizontal cross section Crystalline waterproofing Reinforcing fabric with flexible cementitious coating Figure 1b. Construction Joint Treatment Using reinforcing fabric crystalline mortar Crystalline waterproofing Crystalline mortar groove 1 x 1 (2.5 cm x 2.5 cm) 39. Crystalline Waterproofing corner detail Crystalline Waterproofing Concrete Wall and Slab Interface, slab or ceiling Cove Detail - schematically A cove made of patching mortar. Flexible cementitious coating layer applied over the cove with a strip of reinforcing fabric. Cove size is 2 x 2 (5 cm x 5 cm). Second coat of flexible cementitious coating applied ensuring fabric is completely covered. A strip of reinforcing fabric, approx. 8-10 (20-25 cm) wide 40. Application Slurry application on vertical surfaces Broadcast onto horizontal concrete slabs Admixture to the concrete Ensure moist curing for 4 days Crystalline WaterproofingCrystalline Waterproofing 41. construction joints expansion joints larger, dynamic cracks failing water-stops areas of poor concrete consolidation penetrations through concrete sections It will not waterproof Crystalline WaterproofingCrystalline Waterproofing Limitations 42. Polymer modified cementitious coating Breathable and flexible Various formulations based on application Positive or negative Chemically resistant versions available Crack bridging capabilities 1/16 Flexible CementitiousFlexible Cementitious WaterproofingWaterproofing 43. Waterproofing of foundation walls Water storage tanks in municipal or industrial waste water Potable water facilities Elevator shafts Swimming pools Parking garages Basements Secondary containment structures Concrete roofs Protection of marine structures Uses of Flexible CementitiousUses of Flexible Cementitious WaterproofingWaterproofing 44. Surface preparation Sound concrete surface Thorough cleaning, high pressure water Treatment of inside corners Patching and joint / crack treatment Penetration treatment Saturated, surface damp condition Flexible CementitiousFlexible Cementitious WaterproofingWaterproofing 45. High pressure wash 46. Properly Prepared Surface 47. Flexible Cementitous Coating crack or construction joint treatment Reinforcing fabric with flexible cementitious coating Flexible cementitious coating, two coats, the total thickess 62 mils mimimum (1.6 mm) Flexible Cementitious Coating Crack or construction joint treatment, negative or positive side Crack or Construction Joint Treatment using reinforcing fabric and flexible cementitious coating vertical wall horizontal cross section 48. Application of non-woven reinforcing fabric 49. Flexible cementitious coating treatment of vertical, horizontal corners (coves) A cove made of patching mortar. Flexible cementitious coating layer applied over the cove with a strip of reinforcing fabric. Cove size is 2 x 2 (5 cm x 5 cm). Second coat of flexible cementitious coating applied ensuring fabric is completely covered. A strip of reinforcing fabric, approx. 8-10 (20-25 cm) wide Flexible cementitious coating, two coats, the total thickess 62 mils mimimum (1.6 mm) Flexible Cementitious Coating Concrete Wall and Slab Interface, slab or ceiling Cove Detail - schematically 50. Application Brush or spray apply Two coat application If concrete is less than 6 weeks old, embed woven reinforcing fabric throughout application If concrete is older than 6 weeks, just use fabric over any existing cracks Air cure for 48 hours Flexible CementitiousFlexible Cementitious WaterproofingWaterproofing 51. Brush application of Flexible Cementitious Coating 52. Spray application of Flexible Cementitious Coating 53. Flexible Cementitious Coating with Fabric throughout 54. Roofed waste water facilities; concrete exposed to hydrogen sulfide Digesters Manholes Pumping stations Sewers Secondary containment structures Alternative to epoxy and urethane coatings Uses of Chemically Resistant FlexibleUses of Chemically Resistant Flexible Cementitious WaterproofingCementitious Waterproofing 55. Installation of chemically resistant flexible cementitious coating in waste water treatment facility 56. Epoxy coating failing after one year service 57. Concrete has many advantages, but also limitations Prone to damage by water infiltration Cementitious waterproofing can reduce this by treatment on the positive or negative side to aid in reducing the permeability of the concrete Either crystalline treatment, or application of a flexible cementitious coating ConclusionConclusion