Condition Assessment of Condition Assessment of Waterfront FacilitiesWaterfront FacilitiesDouglas Burke March 8, 2003Frequency: 2 to 6 yrs.Unique Mission within the NavyNFESC provides specialized facility engineering, technical products and services.• 510 Engineers and Scientists• Mostly civilian workforce• Port Hueneme, California• East Coast Detachment, Washington Naval Yard DC• Energy & Utilities• Amphibious & Expeditionary• Environmental• Ocean Facilities• Shore FacilitiesOrdnance FacilitiesPhysical SecurityInstallation Life Cycle ManagementElectronic FacilitiesSHORE FACILITIESSHORE FACILITIESAviation FacilitiesWaterfront FacilitiesCondition AssessmentCondition Assessment--Concrete Materials Concrete Materials --• Scope• Objectives • Structural Components• Inspection Tools• Environmental Conditions• Concrete Sampling• Laboratory TestingScope of the Assessment Scope of the Assessment • Structural Components • Utilities • Fendering Systems• Paints and Coatings• Corrosion • Cathodic Protection SystemsStructural ComponentsStructural Components• Concrete • SteelObjectives Objectives • Quantify type and extent of Defects• Identify Deterioration Mechanisms • Establish a Facility Condition Rating• Certify Structural Adequacy• Prepare a Repair Budget • Predict Remaining Service LifeStructural ComponentsStructural ComponentsSoffitPile CapPilesStructural ComponentsStructural ComponentsBent 6Bent 5Bent 4Girder(longitudinal beam)Structural ComponentsStructural ComponentsConcrete Fender PilesConcrete Sheet Pile CapSteel Sheet PilesStructural ComponentsStructural ComponentsTop DeckStructural ComponentsStructural ComponentsCurbTimber Fender PilesStructural ComponentsStructural ComponentsBollardCleatDouble BitInspection Tools Inspection Tools • Visual • Pick Hammer• Chain • Cover Meter• Core Drill• Crack GaugeTop Deck InvestigationsTop Deck InvestigationsCracks greater than 0.2mm allow direct ingress of corrosive species to the steel rebar.General CracksGeneral CracksGeneral CracksGeneral CracksGeneral CracksGeneral CracksGeneral CracksGeneral CracksGeneral CracksGeneral CracksPoor DrainagePoor DrainageTop Deck Delamination Survey Top Deck Delamination Survey Chain DragSounding with a Hammer“Delam 2000”(Closed Corrosion (Closed Corrosion SpallsSpalls))Closed Corrosion Closed Corrosion SpallsSpallsReinforcement Survey Reinforcement Survey • Locate Reinforcement• Determine Diameter • Determine Concrete Cover PROTOVALE CM9COVERMASTER.ConcreteCoverReinforcingSteelTop Deck: Open Corrosion Top Deck: Open Corrosion SpallsSpallsMechanical DamageMechanical DamageUnder Deck InspectionsUnder Deck InspectionsOpen Corrosion Open Corrosion SpallsSpallsClosed Corrosion Closed Corrosion SpallsSpallsClosed Corrosion Closed Corrosion SpallsSpallsRepaired Crack: Epoxy InjectionRepaired Crack: Epoxy InjectionCorrosion CracksCorrosion CracksA “swim by” inspection of 100% of the concrete piles, from the splash zone to the mud line.Visual Inspection of Piles: Level IVisual Inspection of Piles: Level IA 12” wide band is cleaned to expose the pile surface for inspection at three elevations;• Mud line • Mean Low Water • Mid-depthVisual Inspection of Piles: Level IIVisual Inspection of Piles: Level II(10% of piles)(10% of piles)Visual Inspection of PilesVisual Inspection of PilesLevel IILevel II(10% of piles)(10% of piles)Standard Practice for Probability Sampling of Materials (ASTM E105)• Visual inspection • 5 strikes: geology pick• Photograph• Measure defectsVISUAL DETERIORATION VISUAL DETERIORATION CLASSIFICATIONSCLASSIFICATIONSI - SOFTNESS, EROSION AND SLIGHT CRACKINGVISUAL DETERIORATION VISUAL DETERIORATION CLASSIFICATIONSCLASSIFICATIONSII - CRACKING, SOFTNESS, EROSION AND SOME DELAMINATIONVISUAL DETERIORATION VISUAL DETERIORATION CLASSIFICATIONSCLASSIFICATIONSIII - DELAMINATION TO EXPOSE REINFORCINGVISUAL DETERIORATION VISUAL DETERIORATION CLASSIFICATIONSCLASSIFICATIONSIV - COMPLETE LOSS OF CONCRETELess Frequent DefectsLess Frequent DefectsASR and DEF DamageLess Frequent DefectsLess Frequent DefectsExpansive Reaction due to Silica Fume AgglomerateLumps of Silica FumeLumps of Silica Fume– Many of the large undispersed particles of silica fume have acted like ASR-reactive aggregates. – They have reacted, swollen, and cracked the cement paste.(In the photo they are dried out.) – These particular grains are about 300 µm (microns), i.e. fine sand sizeExtensive and excessive crackingSilica Fume LumpsCement Alkalinity Cement Alkalinity • The high cement content (800 lbs./cu. yd) of the concrete mixture resulted in sufficient alkalis to fuel the expansive reactions of the oversized silica fume particles. • No specific testing of the aggregate or the silica fume concrete was accomplished during construction regarding chemical stability.Lumps of Silica FumeLumps of Silica Fume• Efficient breakdown requires dry mixing of the silica fume with coarse aggregate (and the sand) before water and cement are introduced. Such mixing is not usually done in practice. B. Lagerblad and P. Utkin “Silica granulates in concrete – dispersion and durability aspects”about 300 micronsParticles size should be about 1 micron.– Reactive aggregates in the concrete react with alkalis in the cement and/or seawater creating silica gel which creates expansive forces and causes cracking.ALKALIALKALI--SILICA REACTIONSILICA REACTIONW/C ratio & materials used.Method of preparation and curingPermeabilitySubsequent surface treatmentsSeawater penetrationCrackingASR Swellinglumps of silica fumeEttringite FormationEttringite FormationEttringite FormationEttringite FormationEttringite FormationEttringite Formation1. SULFATE (SO3) REACTS WITH FREE LIME (CALCIUM HYDROXIDE Ca(OH2)) TO FORM GYPSUM (CaSO4)2. THE GYPSUM (CaSO4) REACTS WITH TRICALCIUM ALUMINATE (Ca3Al2) TO FORM ETTRINGITE (Ca6Al2(SO4)3(OH12))3. FORMATION OF ETTRINGITE GEL AND/OR CRYSTALS CREATES EXPANSIVE FORCES WHICH CAUSE CRACKING IN THE CEMENT PASTEETTRINGITE FORMATIONETTRINGITE FORMATIONLess Frequent DefectsLess Frequent DefectsExtensive Network of MicrocracksExtensive Network of MicrocracksThermal Stress and Steam CuringThermal Stress and Steam Curing• Delayed ettringite formation (DEF) damage is identified as a concrete durability problem primarily for steam-cured or heated concretes that have been exposed to high temperatures:1985 ACI 190oF 1999 ACI