Lecture #1 - Concrete Ingredients - Part 1 Flashcards
What is concrete?
Composite material composed of aggregate bonded together with a fluid cement that cures over time.
What are the main concrete ingredients?
Coarse aggregate, fine aggregate, cement, water
What are the additional concrete ingredients?
Cementing material, chemical admixtures, fibers, by-products
What percentage volume and mass does aggregate make up?
60-75% volume, 70-85% mass
How should aggregates be? Why?
Hard (not easily split), less void and less porosity, durable particles, clean, free of absorbed chemicals, free of coating of clay. To make concrete strong, durable, to avoid endangering the hydration and to maintain a good bond between the aggregates and the cement paste.
What is the border between coarse and fine aggregates?
Sieve #4 (4.75 mm)
What is the bulk density of lightweight aggregate?
560-1120 kg/m3
What is the bulk density of normal-weight aggregate?
1200-1750 kg/m3
What is the bulk density of heavyweight aggregate?
greater than 1750 kg/m3
What is the density of lightweight concrete?
1350 kg/m3 to 1850 kg/m3
What is the density of normal-weight concrete?
2200 to 2400 kg/m3
What is the density of heavyweight concrete?
2900 to 6100 kg/m3
What is bulk density?
mass of aggregate/volume of aggregates with voids
What is normal-weight aggregate used for?
Structural applications (like column, wall, beam, slab)
What is lightweight aggregate used for?
Structural and non-structural applications (like concrete panel, architectural stuff)
