Term
| What are the Seven Steps in the modern manufactoring of Portland Cement |
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Definition
- Raw material Storage
- Raw Material Grinding
- Raw Material Blending
- Raw Material Pre-Heating
- Raw Material cooking in Kiln
- Clinker Storage/Cooling
- Gypsum addition
- Cement Grinding
- Cement storage/loading
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Term
| what are the 4 Raw materials for concrete |
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Definition
| Limestone, Sand, Clay and Iron ore |
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Term
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Definition
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Term
Reactions in Kiln
before the burning zone and in the burning zone |
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Definition
Before the burning zone their is the formation of C2S from free lime and silica
In the burning Zone: combination of C2s annd free lime to from c3s |
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Term
| What happens when gypsum is added in the kiln |
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Definition
| 4-6% is added to regulate the setting time of concrete and to improve shrinkage and strength development properties |
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Term
Reactions in kiln
4 points about Impurities |
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Definition
-Impurities exist in clinker (MgO, Alkalis(Na20 and K2O, sulfates)
- They lower the melting temperature & improve combination of lime
- Their incorporation in silicates IMPROVES STRENGTH
- BUT CAN cause durability problems |
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Term
| what is Type 1 Concrete or GU |
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Definition
| Normal - General uses - 90% of used cement |
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Term
| Type 2 concrete or Type MH and Type 5 or Type LH concrete |
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Definition
Type 2 - is Moderate Sulfate Resistance Lower C3A (7.5%)
Type 5 - is High Sulfate Resistnace Lower C3 A (3.5)
C3A is Tricalcuim Aluminate |
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Term
| Type 3 Concrete or Type HE |
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Definition
| Type 3 is High Early Strength and is the result of being ground finer |
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Term
| Concrete Type 4 or Type LH |
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Definition
Is Low Heat of Hydration
Delayed reaction, low heat generated |
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Term
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Definition
Specifically formulated for use in Masonry mortars
Includes limits on max air content and min strength |
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Term
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Definition
| - for use in high temp and pressure down hole ( for exposure up t 120 degrees and 140 MPa |
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Term
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Definition
Ultra fine cements
- ground very fine for use in grouting into fine soil or thin rock fissures
- to stabilize in place materials to provide strength for foundations |
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Term
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Definition
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Term
| what is TRIcalcuim Silicate |
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Definition
| TRIcalcuim Silicate is C3S and combines with other components of the raw mix to form 4 principal compounds about ( 90%) of cement by mass |
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Term
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Definition
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Term
Particle Size and Fineness
- what shape do particles have?
- what percentage of particles are smaller then 45 microns?
- what is the average particle size?
- what is the average overall particle size distribution for modern concrete? |
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Definition
- Individual ANGULAR particles with a range of sizes
- 85%-95%
- the average particle size is around 15 microns
- 370 m2/kg |
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Term
| what is the implication for having finer particle sizes in your concrete? |
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Definition
Finer = particle size means faster hydration, more heat generation
higher early strength, less long term gain |
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Term
Setting behavior
what time period is the initial set
what is the final set time period |
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Definition
initial set 1 to 4 hours
final set 3 to 6 hours |
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Term
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Definition
| rapid setting without much heat liberation can be remixed |
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Term
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Definition
| Very rapid setting with significant heat liberation, cant be remixed (to much gypsum) |
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