9.properties of hardened concrete

Question 1

What is strength

Answer 1

Ability of material to resist stress without failure

Question 2

Types of strength

Answer 2

Compressive strength
Tensile
flexural
Shear strength
Torsional strength

Question 3

Factors affecting concrete strength

Answer 3

• nature of concrete
• intrinsic factors
• extrinsic factors

Question 4

Give three nature of concrete factors that affect concrete strength

Answer 4

Heterogeneity–> concrete consists of different materials with very properties

Porosity –> YouTube free water present in fresh concrete– decreases strength

Flaws –> micro cracks and discontinuity

Question 5

What is intrinsic factors

Answer 5

-Related to the properties of the concrete itself
- aggregate
- itz
- hardened cement paste

Question 6

What is Extrinsic factors

Answer 6

-Related to how the concrete is tested
- specimen parameters
- loading parameters

Question 7

Two types of measuring concrete

Answer 7

—Compressive strength– ratio of maximum Uniaxial load carried by concrete to cross-sectional area of specimen

— Tensile strength
——Different methods
1. Direct and tensile strength
2. Tensile split test
3. Flexural strength

Question 8

What is deformation

Answer 8

Volumetric changes to concrete members due to stresses and environmental effects

Question 9

Give two examples of load depend deformations

Answer 9

The lastic deformations
Creep

Question 10

Give two load independent deformations

Answer 10

Shrinkage
Thermal movement

Question 11

Give six Potential effects of deformations on concrete

Answer 11

Elastic deformations( intestineous and reversible deformation under applied load or stress)
Creep( time dependent increase in deformation under sustained stress)
Beneficial effect
Detrimental effects
Drying shrinkage
Thermal movement