CHAPTER 1: INTRODUCTION Flashcards
(34 cards)
Define CONCRETE
CONCRETE is a mixture of sand and gravel, crushed rocks or other aggregates
Define REINFORCED CONCRETE
REINFORCED CONCRETE is the combination of concrete and steel
Give at least 5 advantages of Reinforced concrete as a structural material
has a considerable compressive strength
has great resistance to fire and water
it is very rigid
it is a low-maintenance material
it has a long service life
can be cast in different shapes
economical for footing, floor slabs, basement, etc.
inexpensive local material
low grade of skilled labor is required
Give at least 3 disadvantages of Reinforced Concrete as Structural Material
It has a low compressive strength
forms are required to hold the concrete until hard
low strength per unit of weight of concrete - Heavy members
members are relatively high
properties vary widely
How many weeks does a normal Portland cement need to achieve sufficient strength to permit the removal of forms?
2 weeks
Portland cement reach their desired strength after how many days?
28 days
It is the common or all-purpose cement
TYPE I (of Portland Cement)
It has a modified cement; it has lower heat of hydration compared to Type I
TYPE II (of Portland Cement)
It is a high-early-strength STRENGTH CEMENT; it will be produced in the first 24 hours
TYPE III (of Portland Cement)
it is a low-heat cement; used for huge concrete structures
TYPE IV (of Portland Cement)
It is used for high-concentration of Sulfate
TYPE v (of Portland Cement)
These are the materials added to the mixture during or after mixing
ADMIXTURES
Identify the common types of Admixtures
Air-entraining Admixtures
Accelerating Admixtures
Retarding Admixtures
Super Plasticizers
Water-proofing materials
It increases concrete’s resistance to freezing &thawing; results to less cracking
Air-entraining Admixtures
It accelerates early strength development
Accelerating Admixture
It is used to slow the setting of the concrete and to retard temperature increases
Retarding Admixtures
These are the admixtures made from sulfonates
It is used to reduce water content in the concrete while increasing their slumps
Superplasticizers
It is usually applied to hardened concrete surface
Waterproofing material
Enumerate the 8 Properties of Concrete
- Compressive Strength
- Static Modulus of Elasticity
- Dynamic Modulus of Elasticity
- Poisson’s Ratio
- Shrinkage
- Creep
- Tensile Strength
- Shear Strength
Based on your understanding, explain compressive strength
Explain*
Based on your understanding, explain the Static Modulus of Elasticity
Explain*
What are the different definitions of Modulus of Elasticity?
Initial Modulus
Tangent Modulus
Secant Modulus
Apparent or long-term Modulus
It is the slope of the stress-strain diagram at the origin of the curve
iNITIAL MODULUS
It is the slope of the tangent to the curve at some point along the curve somewhere in the 50% of the ultimate compressive strength
TANGENT MODULUS
