Concrete in Construction

Study Notes

Concrete is a man-made building material that resembles stone.
The term "concrete" originates from the Latin "concretus," meaning "to grow together."
Concrete is a mixture of aggregates (sand, gravel, or crushed stone) held together by a binder of cementitious paste.

The global annual consumption of concrete is approximately 11 billion metric tons.
Concrete is widely used for various structures, such as dams, pavements, building frames, and bridges.
Its production exceeds that of steel by a factor of 10 in tonnage and more than 30 in volume.

Economical: Concrete is inexpensive and readily available.
Ambient temperature-hardened material: Concrete can gain strength at ambient temperature.
Ability to be cast: Fresh concrete can be poured into various formworks to form different shapes and sizes.
Energy efficient: Concrete production consumes less energy compared to steel.

Quasi-brittle failure mode
Low tensile strength: Concrete's tension strength is about 1/10 of its compressive strength.
Low toughness (ductility)
Low specific strength (strength/density ratio)
Formwork is needed: Fresh concrete requires formwork to hold its shape and support its weight.
Long curing time
Working with cracks

According to unit weight: Concrete can be classified into four categories.
According to compressive strength: Concrete can be classified into four categories.
According to additives: Concrete can be classified based on the materials added to the mix.

w/c ratio (or w/b ratio): Influences concrete properties, such as compressive strength, permeability, and diffusivity.
Cement content: Influences concrete workability, heat release rate, and volume stability.
Aggregate: Influences concrete properties, such as:
- Maximum aggregate size: Influences cement paste requirement.
- Aggregate grading: Influences space filling or particle packing.
- Aggregate shape and texture: Influences workability, bonding, and compressive strength.
- Aggregate/cement ratio: Influences concrete cost, workability, mechanical properties, and volume stability.
Admixtures: Influences concrete properties, such as strength, durability, and workability.
Mixing procedures: Influences concrete properties, such as strength, durability, and workability.
Curing: Influences concrete strength, durability, and overall quality.