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US Army Corpsof Engineers
CHL: Steven Hughes, PhD
Monitoring and Maintenanceof Coastal Infrastructure
Steven A. Hughes, PhD, PECoastal and Hydraulics Laboratory
US Army Engineer Research and Development CenterWaterways Experiment Station
3909 Halls Ferry RoadVicksburg, Mississippi 39180-6199
Email: [email protected]
Materials in Coastal Design(Continued)
US Army Corpsof Engineers
CHL: Steven Hughes, PhD
Materials in Coastal Design
Contents
• Material Requirements• Earth and Sand• Stone• Portland Cement and Asphalt• Steel and Other Metals• Wood• Geotextiles and Plastics
Based on CEM Chapter VI-4
US Army Corpsof Engineers
CHL: Steven Hughes, PhD
Portland Cement and Asphalt
Uses of Concrete in Coastal Construction
• Seawalls, Revetments, Bulkheads. Massive, cast-in-placestructures. Interlocking block armor. Poured cover layersabove water. Sheetpiles.
• Jetties and Breakwaters. Grout. Rib-caps. Filled cellularstructures in mild waves. Weir sections with prestressedsheetpiles.
• Groins. Sheetpiles or concrete panels.• Caissons. Prefab sections. Concrete caps. Other structural
features.(Continued)
US Army Corpsof Engineers
CHL: Steven Hughes, PhD
Portland Cement and Asphalt
Uses of Concrete in Coastal Construction
• Armor Units. High strength concrete for reinforced or
unreinforced cast armor units.
• Piles. Reinforced or prestressed piles for piers and wharfs.
• Floating Structures. Concrete pontoons. Floating
breakwaters.
• Other Applications. Land-based facilities. Outfalls.
Pipelines. Encasing wood or steel structure components.
(Concluded)
US Army Corpsof Engineers
CHL: Steven Hughes, PhD
Portland Cement and Asphalt
Uses of Asphalt in Coastal Construction
• Dikes. Not common in U.S. Many Dutch applications.
• Jetties and Breakwaters. Used only as binder or filler for
rubble mounds. Crest roadway.
• Revetments. Riprap binder for stronger, impermeable slope.
Asphalt slopes where wave action is minimal.
• Roadways and Slope Protection. Bituminous concrete used
for road construction and surfaces on wharfs and quays. Lining
drainage ponds and ditches.
US Army Corpsof Engineers
CHL: Steven Hughes, PhD
Portland Cement and Asphalt
Types of Portland Cement
US Army Corpsof Engineers
CHL: Steven Hughes, PhD
Portland Cement and Asphalt
Important Concrete Properties
• Strength. Based on compression. Bending resistance comes
from reinforcement. Strength increases as water content
decreases. Aggregates and entrained air also factors.
(Continued)
US Army Corpsof Engineers
CHL: Steven Hughes, PhD
Portland Cement and Asphalt
Important Concrete Properties
(Continued)
Typical Compressive Strengths of Concrete
US Army Corpsof Engineers
CHL: Steven Hughes, PhD
Portland Cement and Asphalt
Important Concrete Properties
(Continued)
Compressive Strengths for Different Water-Cement Ratios
US Army Corpsof Engineers
CHL: Steven Hughes, PhD
Portland Cement and Asphalt
Important Concrete Properties
• Durability. Weathering due to freeze/thaw cycles and
restrained expansion. Chemicals can cause cracking. Steel
corrosion problem in salt water. Cavitation and abrasion can
wear away concrete.
• Workability. Mixture's handling, transport, placement, and
finishing behavior. Different requirements for different
structures. Avoid segregation.
(Continued)
US Army Corpsof Engineers
CHL: Steven Hughes, PhD
Portland Cement and Asphalt
Important Concrete Properties• Consistency. Function of water content, aggregates in wet
concrete. Trade-off between strength and "flow." Judged by
"slump."
(Continued)
US Army Corpsof Engineers
CHL: Steven Hughes, PhD
Portland Cement and Asphalt
Important Concrete Properties
• Water Tightness. Improved by low air entrainment and
thorough "working." Improved with admixtures.
• Specific Weight. Varies between 140-160 lb/cu.ft. Depending
on aggregates, mixture ratios and reinforcement.
• Volume Change. Contraction causes cracks. Shrinkage
during curing increases with water content.
(Continued)
US Army Corpsof Engineers
CHL: Steven Hughes, PhD
Portland Cement and Asphalt
Important Concrete Properties(Concluded)
Average Unit Weight of Fresh Concrete
US Army Corpsof Engineers
CHL: Steven Hughes, PhD
Portland Cement and Asphalt
Important Asphalt Properties
• Wide range of bituminous concrete availablewith different characteristics
• Physical properties stem from the asphaltcement (aggregates are durable)
• Not affected by chemicals (except petroleum-based products)
(Continued)
US Army Corpsof Engineers
CHL: Steven Hughes, PhD
Portland Cement and Asphalt
Important Asphalt Properties
• Flexible and conforms to uneven surfaces
• Allows for differential movements
• Can be porous or impervious
• Plastic or elastic properties depending ontemperature
(Concluded)
US Army Corpsof Engineers
CHL: Steven Hughes, PhD
Portland Cement and Asphalt
Asphalt Blending Considerations
• Sufficient quantities of asphalt to ensure mixturedurability
• Proper type and size distribution of aggregates
• Sufficient voids in mixture to allow for slightcompaction without loss of stability andimpermeability
• Good workability of heated mixture for easyplacement
US Army Corpsof Engineers
CHL: Steven Hughes, PhD
Portland Cement and Asphalt
Concrete Construction Practices
• Transport. Objective to deliver to site without altering water-
cement ratio, slump, air content.
• Placement. Keep plastic and free of cold joints. Minimize
lateral movement. Avoid adding water to increase flow. No
high drops or high-velocity discharge. Don't over-vibrate.
• Curing. Prevent rapid moisture loss. Protect from freezing.
• Formwork Removal. Oil forms before placement. No form
removal until concrete can withstand combined dead and live
loads.(Continued)
US Army Corpsof Engineers
CHL: Steven Hughes, PhD
Portland Cement and Asphalt
Concrete Construction Practices
• Reinforcement Cover Layer. Minimum 50 mm cover over
steel with 65 mm in splash zone. Prestressed members 75 mm
and 90 mm.
• Joints and Sealants. Contraction and expansion joints allow
for volume change. Construction joints facilitate construction
sequence.
• Repairs. Fill cracks with epoxy. Grout air holes.
(Concluded)
US Army Corpsof Engineers
CHL: Steven Hughes, PhD
Portland Cement and Asphalt
Concrete Armor Units
• Units are vulnerable to tension breakage with no reinforcement
• Reinforcement cost is high (doubles cost of unit)
• Large units have little tension strength beyond supporting self weight.
Design for NO MOVEMENT.
• High strength concrete lowers risk of breakage
• Special fabrication precautions
• Vibrate to remove all voids
• Units should be properly cured
• Avoid rapid curing to minimize thermal cracks
• Special equipment needed for handling, transport, and placement
US Army Corpsof Engineers
CHL: Steven Hughes, PhD
Portland Cement and Asphalt
Environmental Effects on Concrete
• Pollutants. Sulfates and acids can damage concrete. In general,
most pollutants will not cause damage. Asphalt damaged by
petroleum-based products.
• Water Penetration. Salt water can corrode steel reinforcement and
cause spalling. Periodic wetting and drying may cause cracks.
Asphalt is generally impervious and resistant to water penetration.
• Waves and Currents. No affect on well-designed structures. High
flows at discontinuities may cause cavitation and deterioration.
(Continued)
US Army Corpsof Engineers
CHL: Steven Hughes, PhD
Portland Cement and Asphalt
Environmental Effects on Concrete
• Ice and Temperature Change. Water freezing in cracks causes
spalling and breakage. Ice impacts and ice loading stresses can
damage. Normal temperature differentials are controlled by good
design. Asphalt can melt if exposed to fire, and become brittle if cold.
• Marine Organisms. No food value for marine critters. Barnacles
have no impact other than additional drag. Asphalt is susceptible to
damage from crustaceous organisms.
(Continued)
US Army Corpsof Engineers
CHL: Steven Hughes, PhD
Portland Cement and Asphalt
Environmental Effects on Concrete
• Abrasion. Wind and water borne particles can wear concrete surface
over time. Asphalt resists erosion quite well.
• Seismic Activity. Earthquakes can damage concrete structures by
direct loading. Asphalt is plastic and deforms in earth movements.
• Other Effects. Concrete has good resistance to fire, is not affected
by sunlight, and is hard to vandalize (does provide ample graffiti
canvas).
(Concluded)
US Army Corpsof Engineers
CHL: Steven Hughes, PhD
Materials in Coastal Design
Contents
• Material Requirements• Earth and Sand• Stone• Portland Cement and Asphalt• Steel and Other Metals• Wood• Geotextiles and Plastics
Based on CEM Chapter VI-4
US Army Corpsof Engineers
CHL: Steven Hughes, PhD
Steel and Other Metals
Uses in Coastal Construction
• Steel. Rolled, cast, and stainless• Concrete reinforcement• Pipe piles and H-piles• Sheetpiles• Conventional steel framing• Fendering/mooring components and specialty items• Wire for gabions, etc.• Fasteners
(Continued)
US Army Corpsof Engineers
CHL: Steven Hughes, PhD
Uses in Coastal Construction
• Aluminum Alloys. Corrosion resistant• Buildings: Door and window frames, framing
materials, roofing, and siding.• Decking, catwalks, railings, supports• Fasteners
• Other Metals.• Copper: Electrical wiring, pipes• Brass: Hardware fittings, fasteners, survey
monuments• Monel and Titanium: Rare
(Concluded)
Steel and Other Metals
US Army Corpsof Engineers
CHL: Steven Hughes, PhD
Applicable U.S. Steel Standards
Steel and Other Metals
US Army Corpsof Engineers
CHL: Steven Hughes, PhD
Aluminum Alloy Series
Steel and Other Metals
• 1000 Series. 99% Al, high thermal and electrical conductivity, loweststrength, 1350 is used for wiring.
• 2000 Series. Copper is major alloying element. Less corrosionresistance.
• 3000 Series. Manganese is major alloying element. Roofing and sidingis usually 3004 aluminum.
• 4000 Series. Silicon is major alloying element. Low melting point.Used in welding and brazing wire.
• 5000 Series. Magnesium is major alloying element. Moderate to highstrength, good corrosion resistance, good for welding.
• 6000 Series. Silicon and Magnesium in equal portions. Mediumstrength, heat-treatable, good corrosion resistance. Windows, doorframes, and lamp posts of 6063 aluminum.
• 7000 Series. Zinc is major alloying element. Heat treatable with veryhigh strength.
US Army Corpsof Engineers
CHL: Steven Hughes, PhD
Aluminum Alloy Series
Steel and Other Metals
• Aluminum alloys 5083, 5086, 5052, and 6061 arecommonly used for applications in the marineenvironment
• Alloys from the 1000, 3000, and 6000 series are alsoused, but have less corrosion resistance.
• Aluminum alloys can be used in the splash zone, butare not recommended for continuous immersion.
• Method of tempering the alloy is an importantconsideration.
US Army Corpsof Engineers
CHL: Steven Hughes, PhD
General Physical Properties
• Metals in General:• Homogeneous• Consistent strength• Easily formed into shapes• Vary from rigid to flexible, ductile to brittle, soft to hard.
• Steel:• Easily joined• High tensile strength• Good ductility• Good toughness• Wide availability in stock sizes.
(Continued)
Steel and Other Metals
US Army Corpsof Engineers
CHL: Steven Hughes, PhD
General Physical Properties(Concluded)
Steel and Other Metals
• Aluminum Alloys:• High corrosion resistance• Good strength-to-weight ratios• Different allow series for specific uses.
• Other Metals.• Copper: High electrical conductivity, workability, and
corrosion resistance.• Brass and Monel: High corrosion resistance. Good
strength and workability.
US Army Corpsof Engineers
CHL: Steven Hughes, PhD
Tensile Stress Limits - Steel
Steel and Other Metals
US Army Corpsof Engineers
CHL: Steven Hughes, PhD
Tensile Stress Limits - Aluminum
Steel and Other Metals
US Army Corpsof Engineers
CHL: Steven Hughes, PhD
Tensile Stress Limits - Other Metals
Steel and Other Metals
US Army Corpsof Engineers
CHL: Steven Hughes, PhD
General Construction Aspects
• Galvanic Reaction. Contact
between dissimilar metals
causes corrosion. More noble
metal (cathode) protected by
"sacrificial anode" such as zinc.
(Continued)
Steel and Other Metals
Galvanic Series in Seawater
Most active (least noble)
Least active (most noble)
US Army Corpsof Engineers
CHL: Steven Hughes, PhD
General Construction Aspects
• Chose metals close together on galvanic series
• Electrically insulate the metals at contact points
• Protective coating on the more active metal (anode)
• Place a more active metal in contact with coupled metals as
sacrificial anode (zinc is commonly used)
• Periodically inspect and replace sacrificial anodes to extend
component life
(Continued)
Steel and Other Metals
If dissimilar metals must be in contact...
Mitigating Galvanic Reactions
US Army Corpsof Engineers
CHL: Steven Hughes, PhD
General Construction Aspects
• Protective Treatments.
• Bar steel corrodes rapidly
• Paint or tar coating must be applied and maintained
• Concrete encasement for major support structure
• Galvanizing or chrome plating
• Beware abrasion by sand
• Construction may damage factory-finished components.
(Continued)
Steel and Other Metals
US Army Corpsof Engineers
CHL: Steven Hughes, PhD
General Construction Aspects
• Fasteners and Connections. High-strength bolts have
lessened use of rivets. Field connections should be according
to specs.
• Welding and Brazing. Variety of onsite welding methods.
Oxyacetylene for carbon and alloy steels, cast iron, copper,
nickel, aluminum, and zinc alloys. Arc welding for carbon
steel and critical connections.
(Concluded)
Steel and Other Metals
US Army Corpsof Engineers
CHL: Steven Hughes, PhD
Environmental Effects on Metals• Abrasion. Loss of metal is minor…loss of protective coating can be
serious and lead to rapid corrosion.• Corrosion. Primary concern in coastal construction. Fresh water
polluted with acids can cause severe corrosion. Salt air will corrodeunprotected steel.
• Marine Fouling. Fouling increases corrosion rates in carbon steel,stainless steel, and aluminum. Copper and copper-nickel have bestresistance to biofouling. Metal in contact with the ground can becorroded by bacteria.
• Seismic Effects. Well-designed metal structures can withstandearthquakes. Structural steel is well suited for seismic applications.
Steel and Other Metals
US Army Corpsof Engineers
CHL: Steven Hughes, PhD
Materials in Coastal Design
Contents
• Material Requirements• Earth and Sand• Stone• Portland Cement and Asphalt• Steel and Other Metals• Wood• Geotextiles and Plastics
Based on CEM Chapter VI-4
US Army Corpsof Engineers
CHL: Steven Hughes, PhD
Wood
Uses in Coastal Construction
• General Wood Uses. Seawalls, revetments, bulkheads, piers,
wharfs, sand fences, floating structures, formwork, bracing, blocking.
• Untreated Lumber. Temporary uses as formwork, bracing,
machinery supports, dunnage. Interior framework not exposed to soil
or water.
• Treated Lumber. Can have contact with soil and water. Submerged
lunber should be pressure treated with coal-tar creosote.
(Continued)
US Army Corpsof Engineers
CHL: Steven Hughes, PhD
Uses in Coastal Construction
• Piles and Poles. Used for pile dolphins, guide piles, channel
markers, building foundations, piers, wharfs, trestles, groins, jetties,
powerlines.
• Beams and Stringers. Treated members used for load bearing
structures such as groins, bulkheads, pier decks, wharfs, bracing.
Untreated only used in protected areas.
• Plywood and Laminated Wood. Used as building flooring,
sheathing, gusset plates, concrete forms, signs, floating structures.
Special seawater treatment.
(Concluded)
Wood
US Army Corpsof Engineers
CHL: Steven Hughes, PhD
Physical and Mechanical Properties
• Main Types.
• Hardwoods shed their broad leafs in the fall.
• Most Softwoods are evergreens with needles.
• General Properties.
• Density varies with volume of air cavities.
• Wood strength increases with density.
• Strength varies parallel and perpendicular to grain.
(Continued)
Wood
US Army Corpsof Engineers
CHL: Steven Hughes, PhD
Physical and Mechanical Properties
• Loading Configurations.
• Parallel to Grain. Most strength in tension and compression.
Shear resistance reduced by knots, etc.
• Perpendicular to Grain. Least strength in tension and
compression. Good shear strength.
• Temperature and Moisture.
• Wood expands and contracts, but not much.
• Wood shrinks as it dries.
• Hardwoods change more than softwoods with moisture content.
Wood
(Continued)
US Army Corpsof Engineers
CHL: Steven Hughes, PhD
Physical and Mechanical Properties
Wood
General Characteristics of Common Wood
(Continued)
US Army Corpsof Engineers
CHL: Steven Hughes, PhD
Physical and Mechanical Properties
Wood
(Concluded)
General Characteristics of Common Wood
US Army Corpsof Engineers
CHL: Steven Hughes, PhD
General Construction Aspects
(Continued)
Wood
• Protective Treatments.
• Treatment prevents marine borers, etc.
• Pressure treat with coal-tar creosote formaximum penetration.
• Untreated wood piles can be encased inprotective armor.
• Avoid field cutting or boring of treated lumber.
US Army Corpsof Engineers
CHL: Steven Hughes, PhD
General Construction Aspects(Concluded)
Wood
• Fasteners and Connections.
• Metal connectors should be protected fromcorrosion.
• Adhesives should be water-proof.
• Restrict field-applied adhesives to secondaryjoints.
US Army Corpsof Engineers
CHL: Steven Hughes, PhD
Wood
Environmental Effects on Wood• Water will penetrate and cause swelling with strength reduction.• Polluted water may help preserve wood by reducing oxygen that
supports wood-attacking marine biota.• Marine organisms are principal cause of wood destruction for
immersed timbers and piles. Proper preservatives are essential.Marine plants do not seem to harm wood, but may cause slipperysurfaces.
• Dry wood can catch fire, but large structural members can toleratesome fire damage before failing.
• Abrasion by harder objects can reduce load bearing cross section.• Wood structures absorb impact energy well.• Human activities and vandalism can wear wood structures.
US Army Corpsof Engineers
CHL: Steven Hughes, PhD
Materials in Coastal Design
Contents
• Material Requirements• Earth and Sand• Stone• Portland Cement and Asphalt• Steel and Other Metals• Wood• Geotextiles and Plastics
Based on CEM Chapter VI-4
US Army Corpsof Engineers
CHL: Steven Hughes, PhD
Geotextiles and Plastics
Uses of Geotextiles in Coastal Construction
• Filters. A fabric layer between sand or soil andoverlying gravel/stone layer that permits waterdrainage. Replaces granular filters.
• Geotextile Bags. Large bags filled with sand arestacked and used as coastal structures (groins,seawalls, etc.)
• Miscellaneous Uses. Seperate different soil layers.Control bank erosion. Cap contaminated dredgematerial. Provide drainage. Reinforce soil banksagainst lateral movement.
US Army Corpsof Engineers
CHL: Steven Hughes, PhD
Geotextiles and Plastics
Typical Uses ofGeotextile Fabric inCoastal Revetment
US Army Corpsof Engineers
CHL: Steven Hughes, PhD
Geotextiles and Plastics
Advantages of Geotextiles in Coastal Construction
• Filtering characteristics are uniform• Fabrics can withstand tensile stress• Geotextile placement is more easily controlled• Underwater placement likely to be more successful
than comparable gravel filters• Inspection and quality control is quick and accurate• Local availability is not a cost consideration
US Army Corpsof Engineers
CHL: Steven Hughes, PhD
Geotextiles and Plastics
Disadvantages of Geotextiles in Coastal Construction
• Difficult to repair damaged in-situ fabric, particularlyunder several layers of stone
• Some fabrics are relatively impervious to rapidhydraulic transients, leading to uplift pressures(design issue)
• Susceptible to undermining at structure toe if notproperly anchored
US Army Corpsof Engineers
CHL: Steven Hughes, PhD
Geotextiles and Plastics
Other Forms of Plastic• High-strength nylon fabric.
• Flexible concrete forms• Grout-filled plastic tubes
• Impervious plastic sheets (visqueen).• Liners and covers to prevent seepage• Shield unprotected metal or timber during construction
• Highly porous plastic mesh (dune fence).• High-strength molded plastic.
• Fenders• Line and protect piles• Polyester pipe to replace steel pile• PVC pipe to 25 cm diameter• Epoxy resins
US Army Corpsof Engineers
CHL: Steven Hughes, PhD
General Design Requirements
• Tensile Strength. Resist tearing by movement of
overlying materials.
• Elongation at Failure. Pore elongation results in soil
loss.
• Puncture Resistance. Survive placement of overlying
materials and movement of materials.
• Abrasion Resistance. Resistance to constant chaffing
by overlying materials.
(Continued)
Geotextiles and Plastics
US Army Corpsof Engineers
CHL: Steven Hughes, PhD
General Design Requirements
• Durability. Must perform consistently over structure life• Site-Specific Factors. Freeze/thaw conditions or
exposure to chemicals.• Construction Factors. More difficult to place
underwater. Wave action may cause excessivemovement before overlayer can be placed.
(Concluded)
Geotextiles and Plastics
US Army Corpsof Engineers
CHL: Steven Hughes, PhD
Geotextile Material Properties
Geotextiles and Plastics
US Army Corpsof Engineers
CHL: Steven Hughes, PhD
Minimum Geotextile Fabric Requirements
Geotextiles and Plastics
US Army Corpsof Engineers
CHL: Steven Hughes, PhD
Geotextile Installation Considerations
Geotextiles and Plastics
• Geotextile Placement.• Lay loosely, free of wrinkles, creases, and folds. Avoid stretched
fabric.
• For slopes exposed to waves begin at slope toe and proceedupslope with upslode panel overlapping downslope panel.
• In currents the upstream panel should overlap the downstreampanel.
• Properly terminate fabric to protect undermining.
• Horizontal underwater placement, start at structure and proceedaway from the structure.
• Overlying gravel layers must be permeable
• Placement of overlying stones begin at toe and proceed upslope.
• Avoid puncturing fabric during stone layer construction.
(Continued)
US Army Corpsof Engineers
CHL: Steven Hughes, PhD
Geotextile Installation Considerations
Geotextiles and Plastics
• Securing Pins.• Should be 5 mm in diameter and capable of holding 3.8 cm
diameter washer.
• Minimum pin length of 45 cm for medium to high densitysoils (longer for looser soils).
• Place at overlap midpoints.
• Pin spacing at maximum of 0.6 m for slopes steeper than 1-on-3, maximum of 1.0 m for slopes between 1:3 and 1:4, and1.5 m for milder slopes.
• Use additional pins as needed to prevent fabric slippage.
(Continued)
US Army Corpsof Engineers
CHL: Steven Hughes, PhD
Geotextile Installation Considerations
Geotextiles and Plastics
• Seams and Joins.• Lengths can be long, but width of sheets is limited by
practical considerations of manufacture and transport.
• Wider panels reduce number of overlaps (most probablecause of error during placement)
• Above water, overlaps should be at least 45 cm andstaggered.
• Below water, overlaps should be at least 1 m.
• Fabric seams can be glued or sewn (sewn preferred onsite).
(Continued)
US Army Corpsof Engineers
CHL: Steven Hughes, PhD
Geotextile Installation Considerations
Geotextiles and Plastics
• Geotextile Repairs.• During construction, repair damage by cutting out fabric and
replacing with a section giving 0.6 m overlap all around.Edges of replacement fabric should be placed beneathoriginal panel.
• Replace entire panel if tensile strength is needed to reinforceslope.
• Remove overlying stone layers to expose damagedgeotextile fabric beneath rubble slopes.
(Concluded)
US Army Corpsof Engineers
CHL: Steven Hughes, PhD
ConstructionLimitations:QuarrystoneRevetment
Geotextiles and Plastics
US Army Corpsof Engineers
CHL: Steven Hughes, PhD
ConstructionLimitations:BlockRevetments &SubaqueousApplications
Geotextiles and Plastics
US Army Corpsof Engineers
CHL: Steven Hughes, PhD
Environmental Effects on Geotextiles and Plastics
Geotextiles and Plastics
• Chemical and Biological. Generally notbiodegradable, not affected by chemicals found incoastal waters. Alkalis and fuel products can destroysome plastics. Bacterial growth can clog fabric.
• Ultraviolet Radiation. Plastics deteriorate insunlight, but stabilizers can be added duringmanufacture. Not problem for submerged or coveredfabric.
• Fire. Will burn/melt and may release toxic fumes.
• Other Factors. Impact loads, abrasion, vandelism.
US Army Corpsof Engineers
CHL: Steven Hughes, PhD
Conclusions
• Coastal projects require a large quantity ofconstruction materials
• Proper design requires an understanding materialproperties
• Material specifications are important in designdocuments
• Field engineers must be knowledgable aboutmaterials used in the project
• Inspectors must assure material quality is high andappropriate handling techniques are used duringconstruction