Concrete Construction Materials Quiz

Concrete

• Concrete is a construction material made from Portland cement, aggregates, and water.
• Normal-weight concrete typically weighs 140-160 lb/cu ft.
• Lightweight insulating concrete can weigh 15-90 lb/cu ft, and has a 28-day compressive strength of 100-1000 psi.
• Mass concrete is used in structures like dams where the weight provides the main strength.
• Heavyweight concrete is made with heavy aggregates like barite, magnetite, and steel; mainly used for radiation shielding.
• Refractory concrete is cast into shape before placement.
• Leveling concrete brings the surface to the desired grade.
• Edging rounds off slab edges to prevent chipping.
• Screeding is moving a straight edge across newly-placed concrete to smooth it.
• Joint preparation uses premolded inserts in slabs to control cracking due to shrinkage.
• Bleeding is dry materials settling to the bottom of concrete, pushing the water to the surface.
• Troweling is finishing slabs with a tool to prepare them for surface finishes like tiles, carpets, and paint.
• Scaling is breaking away of hardened concrete surface.

Harbor

• A harbor is a protected water area for safe ship accommodation, cargo transfer, refueling, repairs, etc..
• Natural harbors are protected from storms by natural land formations.
• Artificial harbors are protected by breakwaters or man-made structures like dredging.
• A port is a sheltered place where a ship can receive or unload cargo. It includes the harbor with approach channels and anchorage areas.
• A fairway is a navigable channel for ships within a harbor or offshore.
• A wharf is a continuous structure parallel to the sea or rivers for loading/unloading cargo.
• A pier is a structure built into the water, not parallel to the coast, for ships to dock.
• A jetty is similar to a pier but may be longer.
• A dolphin is a berth structure for mooring ships in open water.
• A significant wave is a hypothetical wave with the average height and period of a group of waves.
• The highest wave is the tallest wave in a group.
• The mean wave has the average height and period of all waves in a group.

Deepwater Waves, Sea Levels, and Coastal Phenomena

• Deepwater waves are waves where the water depth is at least half the wavelength.
• Mean Sea Level is the average sea water level over a 19-year period.
• Mean Low Water is the height of low tide over 19 years.
• Mean Lower Low Water is the average height of the lowest low tides over 19 years.
• Storm Surge is the abnormal rise in sea level due to a typhoon (including atmospheric pressure reduction and wind stress).
• Tsunamis are waves resulting from large-scale sea floor movements (e.g., earthquakes).
• Seiches are oscillations of water level with periods from a few minutes to tens of minutes.
• Seal Coat is a thin bituminous surface treatment for roads.
• Tack Coat is an initial application of bituminous material onto certain surfaces (concrete, blocks, etc.).
• Prime Coat is an application of bituminous material onto a previously prepared surface (roads) before additional layers are applied.
• Perception Time is the driver's time to realize brakes are needed.
• Intellection Time is the time required to understand a situation.
• Emotion Time is the time for emotional reaction to a situation (fear, anger).
• Volitional Time is the time taken for final action.

Traffic Signs and Roadway Elements

• Traffic signs are devices used to regulate, warn, or guide traffic via words or symbols.
• Regulatory signs inform traffic laws.
• Warning signs alert road users about conditions on or near the road.
• Guide signs provide information about directions, distance, and routes.
• Roadwork signs alert users of temporary hazards in roadwork areas.
• Overhead signs show info on wide multi-lane roads where lane use control is needed.
• Plate Line Capacity is the volume of a bucket with the outer edges followed.
• Struck Capacity is the bucket's volume when load is struck off flush against edges.
• Water Line Capacity is the edge level material in a bucket.
• Heaped Volume is the maximum volume of material in a bucket before spillage.
• Grade Resistance is the component of vehicle weight acting parallel to an inclined surface.
• Rolling Resistance is tire flexing and penetration on the travel surface.
• Total Resistance is the sum of grade resistance and rolling resistance.
• Aggregate is used in concrete to reduce cost and shrinkage.
• Water is needed for the chemical reaction to create hardened concrete.
• Hydration is the reaction between cement and water to form hardened cement.
• Water reducing agents improve concrete workability without changing consistency.

Concrete Additives

• Retarders slow the hardening rate of concrete.
• Accelerators decrease setting time and increase early strength.
• Pozzolans reduce heat generated during hydration, increasing workability and reducing segregation.
• Plasticizers increase workability.
• Batching is the process of proportioning cement, water, aggregates, and additives before mixing concrete.
• Admixtures are materials other than cement, aggregates, or water to alter concrete properties.