David Rivera
Chong 252
3.10.21
Assignment 7 (Part 1)
1. Why is it called hydraulic cement?
- Modern invention
- Because made from finely ground mixture of limestone and clay
- Content moisture and changes its property
- Form of powder
2. Why is steel reinforcement inserted into concrete?
- Good compressive strength
- Increase its tensile strength and resilience
3. What are the ingredients of concrete?
- Sand
- Fine aggregate
- Rock, small pebbles
- Bind together using cement
4. Describe the process of concrete manufacturing.
- Materials are extracted from the earth, transported, crushed, ground, proportion and
blended into a very fine powder. Materials are burned in a kiln
5. List down and describe the different types of concrete specified in ASTM C150
- Type I
- Normal
Type IA
- Normal
- Air entraining
Type II
- Moderate resistance to sulfate attack
Type IIA
- Moderate resistance to sulfate attack
- Air entraining
Type III
- High early strength
Type IIIA
- High early strength
- Air entraining
Type IV
- Low heat of hydration
Type V
- High resistance to sulfate attack
6. What are the commonly used aggregates (both natural and artificial).
Natural:
- Seashells
- Marl
- Chalk
- Clays
- Limestone
- Iron ore
- bauxite
Artificial:
- Fly ash
- Furnace slag
- Concrete thermally concrete
- Shale
- Clay
- Other minerals
7. What factors control the strength of concrete?
- Porosity
- Size distribution
- Moisture absorption
- Shape and surface texture
- Strength, soundness, elasticity, density
- Contamination or detrimental substance
8. What is the relationship between aggregate and concrete?
Structural weight concrete:
- Roughly 80% or less of the weight of ordinary concrete
- Reduces structure weight saves costs
- Lower thermal conductivity increases resistance to building fires
9. What are the functions of water in concrete?
- combine chemically with the cement as concrete hardens.
10. What are the purposes of Supplementary Cementitious Materials (SCMs)?
- Increases concrete strength and durability
11. List down and describe the purposes of adding admixtures into concrete.
- Air-entraining
- Water reducing (do not want to have so much water because it comprises water
quality)
- Cure accelerating or retarding
- Workability modifying
- Shrinkage reducing
- Corrosion inhibiting
- Freeze protecting (for cold weather concreting)
- Coloring
- High strength concrete
12. What are the functions of water in concrete quality control and placement?
- workability of concrete
13. List down the definitions of concrete quality.
- Workable when wet
- Ease of placing
- Consolidating, and finishing structural properties when hardened
- Strength, stiffness, durability
- cost
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