Concrete Science: Materials, Safety, and Professional Practices
Laboratory Safety and Chemical Management
Chemical Hazards and Safe Handling
- Shrinkage-Reducing Admixture: Product or product residue may explosively combust.
- Superplasticizer: Kills fish and ruins water; never pour down a drain!
- Colloidal Silver: Known to cause birth defects.
- Silver Nitrate Solution: A poison, oxidizer, and corrosive.
- Nitric Acid + Nitrobenzene: This combination results in a spontaneous explosion. Always ensure separate storage for acids versus bases.
Essential Laboratory Personal Protective
Read MoreElectrical Circuits, Construction Materials, and Tiles
Electrical Circuits
Electric current is formed by electrons jumping from one atom to another, and this movement generates electricity.
Voltage is the potential difference that makes the electric current flow through a conductor. A potential difference, tension, or voltage must exist for electric charges to move through a conductor in a given time.
Ohm’s Law
- Current = Amps = I
- Voltage = Volts = V
- Resistance = Ohm = R
In a continuous electric circuit, electrical power is produced by the movement of electrons.
Read MoreUnderstanding Gypsum, Lime, and Cement: Properties and Uses
Types of Casts
Gypsum
Gypsum Black: Obtained from algez and contains many impurities. It is calcined directly, often containing ashes and blackened smoke. It is used in works where high quality is not required.
Tendido: Black chalk.
- Guarnecido
- White gypsum plaster
Gypsum White: In cases of the greatest purity and fineness of grind, it is much higher in quality than black chalk and requires more careful calcination. It is used in coatings and is also called plaster and stucco.
Escayola: White plaster of
Read MoreReinforced Concrete: Properties and Uses
Reinforced Concrete
Reinforced concrete is a composite material formed by combining cement, water, fine aggregate (sand), coarse aggregate (crushed stone or gravel), and air. Admixtures, also known as additives, can be included to modify the properties of the fresh or hardened concrete. The concrete mixture is placed in formwork and then cured to facilitate the hydration reaction, a chemical process that produces a hard, rock-like material.
Aggregates
- Fine Aggregates: Typically natural or manufactured
Cement Manufacturing, Properties, and Types
Cement Manufacturing Process
Cement is produced using limestone, rich in calcium oxides, and a silica-rich component like clay or blast furnace slag. These are mixed and heated in a rotary kiln, creating clinker, which contains:
- Dicalcium silicate
- Tricalcium aluminate
- Tricalcium silicate
- Tetracalcium ferroaluminate
Cement Properties
Specific Weight (Density)
The specific weight is the ratio of cement weight to its actual volume. It’s measured using a Chatelier flask, determining the displacement of liquid
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