Concrete Construction

Question 1

What is concrete?

Answer 1

Concrete is the composite material consist essentially of aggregate (coarse and fine) particle embedded in a binding medium

Question 2

What makes a paste?

Answer 2

Cement + water

Question 3

What can other additions to concrete include?

Answer 3

Reinforcing steel

Question 4

What is the function of paste?

Answer 4

To bind the aggregate

Question 5

What is the process of concrete?

Answer 5

1. Mix
2. Transport
3. Place
4. Finish

Question 6

What are hydration products?

Answer 6

-Hydration products are substances formed when water reacts with a compound, like cement, leading to hardening and strength in concrete.
- They will precipitate to form solids

Question 7

What are the reactants in making ions and forming hydration products?

Answer 7

Cement phases (C_3S) + H20

Question 8

What does SEM stand for?

Answer 8

Scanning electron microscope

Question 9

What is Motar consist of?

Answer 9

Paste + fine aggregate

Question 10

What does Concrete consist of?

Answer 10

Paste + coarse aggregate

Question 11

What are advantages of concrete?

Answer 11

• Fire resistant
• Cost effective
• Durable
• Insulator
• Strong in compression
• Made from the most common elements in the Earths crust
• Dampens vibrations

Question 12

What are disadvantages of concrete?

Answer 12

• Weak tension
• Ugly
• Large self-weight
• Hard to reuse
• Porous material
• Can have long term deformations - creep and shrinkage
• Not widely recycled

Question 13

What is cement clinker?

Answer 13

• Cement clinker is a solid material produced in the manufacture of Portland cement as an intermediary product.
• Clinker occurs as lumps or nodules

Question 14

How can we make better concretes?

Answer 14

• Crack resisting concrete
• Hydrophobic concrete
• Self-healing concrete
• Low-carbon concretes
• Self-sensing concrete

Question 15

How do voids appear in cement?

Answer 15

Voids come from the remnants of the water - left over space (capillary pores)

Question 16

Why can voids be bad?

Answer 16

Makes porous concrete → corrosion

Question 17

What are the raw materials used in cement?

Answer 17

Limestone and clay

Question 18

What is the most common cement?

Answer 18

Portland

Question 19

What does clinker consist of?

Answer 19

• Calcium Silicates
• Aluminates
• Ferrites

Question 20

What controls the setting time of cement?

Answer 20

Gypsum

Question 21

What is aggregate made of?

Answer 21

Sand and gravel

Question 22

Plasticisers what are they?

Answer 22

Give concrete more workability and allow it to be moulded

Question 23

What’s hydrophobic concrete?

Answer 23

Repels water

Question 24

How much CO2 does cement contribute to?

Answer 24

The manufacture of cement produces about 0.9 pounds of CO2 for every pound of cement

Question 25

What did Thomas Edison do with concrete?

Answer 25

Edison Portland cement was used extensively for buildings, roads, dams, and other structures, including Yankee Stadium

Question 26

When did Edison build the concrete house?

Answer 26

1910

Question 27

What is usually concretes service life?

Answer 27

100 -120 yrs

Question 28

What is usually made from concrete?

Answer 28

- Pavements - Rail sleepers - Nuclear structures

Question 29

How much of the raw materials extracted goes into concrete?

Answer 29

Half

Question 30

How much concrete is there for every person on Earth every year?

Answer 30

1m^3

Question 31

What are major constitutes in Portland Clinker?

Answer 31

- CaO - SiO2 - Al2O3 - Fe2O3

Question 32

For every ton of cement produce how much CO2 released?

Answer 32

1 ton