Please enable JavaScript.

Coggle requires JavaScript to display documents.

Civil Engineering - Coggle Diagram

- - - - It controls the long-term behaviour, influence strength, young's modulus, creep and durability
    - - Water Content
        
        Higher water content, higher workability
      - Fineness of Cement
        
        Finer Cement, faster loss of workability
      - Aggregate Shape
        
        More angular, more water demand
      - Grading
        
        uniform grading leads to better workability
      - Admixture
        
        accelerators, retarders, plasticisers
      - Time
        
        Timing of cement hydration
      - Temperature
        
        Higher Temperature, Loss of workability
  - - - Coarse aggregates separate towards the bottom and cement paste forms a scum at the top
    - - Increase Air Content
      - Reduce w/c ratio
      - Increase rate of hydration
  - - - Leaves pockets of low density
      - No bleeding may also be a problem
        
        Without the layer on top, it may cause the concrete to dry out rapidly.
    - - Too much water
      - less fines in the cement mix
      - Poor grading of aggregates
      - Overworking the concrete
  - - - Moisture is lost from the surface
      - Cracks are parallel
      - If bleed water replaces water loss, cracking is less likely
    - - Low Relative Humidity
      - High Surface Temperatures
      - High Wind Speeds
    - - Moist aggregates
      - cover the concrete
      - erection of windbreaks & sunshades
      - add plastic fibres
  - - - It is best to cover curing concrete before curing to stop moisture loss
        
        Plastic Sheeting
        
        Spray a membrane
- - - - Sugars
      - Sulphates
      - Chlorides
  - - - Accelerators
        
        Increase strength gain at early age
        
        CaCl
        
        Doesn't increase final strength
      - Retarding Agents
        
        reduces rate of evolution of heat
        
        Needed for large concrete pours
      - Water Reducing
        
        Reduces the amount of water for a given workability
      - Air Entraining
        
        generates evenly dispersed air bubbles in the mix
        
        improves agents frost and marine environments
      - Superplasticisers
        
        forms high flowing concrete
        
        Allows for removal of water and thus higher strength
      - Self-compacting
        
        high flowing concrete
        
        doesn't require compaction
      - Foamed
        
        High Flowing concrete with bubbles and no stone
  - - - Coarse
        
        5mm>
        
        50%-80% of Concrete Mix
        
        Used to...
        
        Pack Efficiently
        
        Reduce Spaces
        
        Improve Strength
        
        Improve Drying Shrinkage
        
        Requirements
        
        Hard
        
        Strong
        
        Clean
        
        Free of Impurities
        
        Free of organic material
        
        Free of dust
        
        Types
        
        Lightweight
        
        Weak Porous Solids
        
        Good Thermal Properties
        
        High Density
        
        Radioactive screening
        
        Normal Density
        
        Most Gravels & Crushed Rock
      - Fine
        
        5mm<
  - - - Entrapped Air
        
        0.1
      - Entrained Air
        
        0.01-1
      - Capillary Pores
        
        0.0001-0.01
      - Gel Pores
        
        0.000001-0.00001
  - - - Ordinary Portland Cement
      - Rapid Hardening Portland Cement
      - Sulphate Resistant Portland Cement
      - White Portland Cement
    - - Quarrying
        
        Limesone
        
        Ran through Rock Crusher
        
        Partials Mixed and ran through rotary kiln
        
        CO2 is driven off the limestone (Calcines)
        
        This forms Clinker, a fine powder
        
        Gypsum is added
        
        1 more item...
        
        Shale
        
        Silica
        
        Iron Oxides
    - - Blast furnace Slag Cement
        
        Steel Energy
        
        Makes up 70% of OPC
        
        Weaker early age strength
        
        Reduced early heat of hydration
        
        Much lower carbon footprint
      - Pulverised-fuel Ash Cement
        
        Coal Electricity
      - Rice Husk Ash Cement
        
        Agriculture Industry
      - Silica Fume
        
        Silicone Industry
    - - W/C Ratio
        
        Setting and Hardening results from a chemical reaction, not from a drying process
        
        This is exothermic & irreversable
        
        This produces heat of hydration
    - - Initially Rapid
        
        gets progressively less rapid
        
        This strength gain continues indefinitely in a process known as curing