Chapter 1: Portland Cement Chemistry

Question 1

What is Portland Cement responsible for

Answer 1

Responsible for binding aggregate together = producing concrete

Question 2

Portland Cement is made from what 3 elements

Answer 2

Limestone, clay, gypsum

Question 3

Cement composition

Answer 3

SiO2, Al2O3, Fe2S3, CaO, MgO, So3

Question 4

ASTM C150 what are the 5 types of cement

Answer 4

Type 1: general use
Type 2: moderate sulfate resistant
Type 3: high early strength
Type 4: low heat of hydration
Type 5: high sulfate resistant

Question 5

What are the 4 cement composition

Answer 5

C2S
C3S
C3A
C4AF

Question 6

C2S

Answer 6

Dicalcium Sulfate

Question 7

C3S

Answer 7

Tri calcium Sulfate

Question 8

C3A

Answer 8

Tri calcium aluminate

Question 9

C4AF

Answer 9

Tetracalcium aluminate

Question 10

What are the 3 main cement chemical hydrations equations

Answer 10

C2S + h20 = CH + CSH
C3S + h20 = CH + CSH
C3A + h20+ gypsum = Ettringite

Question 11

What is CH

Answer 11

Calcium Hydroxide

Question 12

What is CSH

Answer 12

Calcium Silicate Hydrate

Question 13

Why does normal concrete stay plastic (workable) for a few hours ?

Answer 13

Takes time for cement to get supersaturated, having to produce ions, needing about 4 hours to hydrate and have chemicals bond together

Question 14

What are the 4 hydration stages

Answer 14

1. Initial
2. Dormant
3. Acceleration
4. Deceleration

Question 15

Impact of SCM - retarders

Answer 15

Increase stage 2

Question 16

Impact of SCM - Accelerators

Answer 16

Push the saturation process

Question 17

Impact of SCM - Accelerators

Answer 17

Push the saturation process

Question 18

Differences of pozzolanic

Answer 18

Reacts with CH to produce CSH

Question 19

Differences of Cementious

Answer 19

High amounts of SiO and CaO slag reacts with water to create CSH

Question 20

What SCMs are pozzolanic

Answer 20

Fly ash type F,
Silica fume,
Metakolin
Volcanic ash
Natural pozzolanic

Question 21

What SCMs are cementious

Answer 21

Fly ash type c
Slag
Any cementious material is considered pozzolanic

Question 22

Poreous solution

Answer 22

Water inside concrete

Question 23

What is PH level of concrete

Answer 23

13 or 14

Question 24

Silica Fume has high amounts of what

Answer 24

SiO2

Question 25

Slag has high amounts of

Answer 25

CaO, SiO2

Question 26

CAC has high amounts of

Answer 26

Al and Ca

Question 27

CSA has high amounts of

Answer 27

SO3 and Ca

Question 28

Cement has high amounts of

Answer 28

CaO

Question 29

How does silica fume affect concrete

Answer 29

Increase workability with less water

Question 30

How does fly ash affect concrete

Answer 30

Decrease workability and increase high early strength

Question 31

What is amphorous particles

Answer 31

Disorganized particles

Question 32

What is crystalline particles

Answer 32

Organized molecules

Question 33

What is interfacial transition zone

Answer 33

Aggregate should be stronger than desired cement strength

Question 34

What is CSA

Answer 34

Calcium Sulfo Aluminate Rapid set, very reactive

Question 35

What is CAC

Answer 35

Calcium aluminate cement Slow set, chemical resistant

Question 36

What is ASTM C150

Answer 36

Standard specification for Portland Cement

Question 37

What is ASTM C595

Answer 37

Standard Specification of Blended Hydraulic Cement

Question 38

What is ASTM C 1157

Answer 38

Performance Specifications of Hydraulic Cement

Question 39

What is prescription specification

Answer 39

Ingredients inside concrete. What and how much

Question 40

Finer cement does what

Answer 40

Faster it will set and gain strength

Question 41

What are the Blended Hydraulic Cement in ASTM C595

Answer 41

Type IS: slag Type IL: limestone Type IP: pozzolanic Type IT: ternary blended

Question 42

What are Hydraulic Cement in ASTM C 1157

Answer 42

Type GU: general use Type MS: moderate sulfate Type HS: High Sulfate Type MH: moderate heat of hydration Type LH: low heat of hydration Type HE: high early strength

Question 43

Quality control measure of concrete

Answer 43

Slump, Density Volume, Temperature Air content Water content Compressive strength

Question 44

Quality control measures of cement

Answer 44

Fineness Chemical composition Set time Air content of mortar Autoclave expansion

Question 45

Quality control measures of cement

Answer 45

Fineness Chemical composition Set time Air content of mortar Autoclave expansion