Building Systems

• Cement (Kiln fired limestone with small amounts of clay and other materials that is ground into powder)
• Water
• Aggregate (Fine, coarse)

• Type 1 - normal Portland cement
• Type 2 - moderae Portland cement which is resistant to moderate sulfate action
• Type 3 - high-early-strength
• Type 4 - low-heat
• Type 5 - sulfate-resistant

made with expanded shale or slate aggregate

perlite aggregate or foaming agent

Material added to concrete to alter its properties, ex: air-entraining agents, accelerators, surface-active agents or sufactants, water-reducing agents, superplasticizers, coloring agents, etc

• Adds air bubbles to the concrete's cement paste
• Goal is to reduce the cracking of concrete during freeze/thaw cycles.
• Increases workability and reduces segregation and bleeding in fresh concrete.

• Decreases the water-cement ratio, decrease cement content, decrease the water needed to produce a certain slump, or increase slump.
• Strength of the concrete increases when water reducers are added because water-cement ratio decreases.
• Tendency to increase drying shrinkage

• Gives the concrete the ability to flow, increases the slump while maintaining cohesion
• Good for thin-section placement, dense laid steel areas, underwater placements, etc

• Speeds up the rate of setting and the development of strength.
• Most common: Calcium chloride.
• Possible discoloration, shrinkage, reinforcement corrosion

• Increase the setting time of concrete
• Does not decrease the concrete temp, it increases the bleeding rate and capacity.

• Slows rust formation on reinforcing steel.
• Commonly used in parking structures, marine structures and bridges where chloride salts is prevalent.

• Added for aesthetic purposes and some safety apps.
• no more than 10% of the weight, but less than 6% will not change the properties.

• Glasslike particles resembles Portland cement
• Increases the workability of concrete, acting like a lubricant.
• Good for forming crevices and small openings

• Used as an aggregate in concrete.
• Similar consistancy to sand.

• Steel reinforcing bars
• Steel mesh
• Fiber reinforcement

• Most commonly used in concrete
• Heavy-duty reinforcement agains tension and flexure for concrete
• To counter corrosion, rebar is available in other forms besides common steel.
• 3/8"

• Steel - strength
• Glass - the most tensile strength
• Synthetic/Plastic - most common, polypropylene
• Natural - comparable strength but some are lacking

• hot-rolled steel sections with ribs or deformations for better mechanical bonding
• Sizes refer to diameter in 1/8"

• Not as heavy duty as rebar
• Main purpose is to control concrete cracking, not eliminate it altogether.