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- Cement (Kiln fired limestone with small amounts of clay and other materials that is ground into powder)
- Aggregate (Fine, coarse)
Portland Cement Types
- 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.
Concrete reinforcing fibers
- 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.