Line G1 Flashcards
Concrete
What is the definition of plain concrete?
Concrete without any reinforcement
Thermal expansion of concrete or steel?
Interesting enough it’s the same both
Cement Pace bonds only two?
One. Aggregates
Two. Reinforcing steel
Three. Concrete forms.
For both steel and aggregates
Both steel and aggregates
Pre-stressed cement is?
Under tension at all times or in a state of precompression?
In a state of precompression
Pretensioning in cement is what?
Before concrete place
Which of the following shapes is not a type of concrete shell roof?
Barrel roof, dome roof, flat roof, folded plate roof,
Flat roof
What is the most common way to prevent telegraphing of forming materials for example the grain of a wood being left as an impression on the Finish concrete?
Liners made of rubber or plastic can prevent the telegraph in material and and can also be used to place patterns directly on the concrete
The term concrete means construction from
Bricks or blocks
Concrete with air entrainment has?
Microscopic air bubbles
I cement make sure applied with compressed air is called?
Air entertainment or Shortcreat
Shortcreat
Advantages of previous concrete?
All of the below
It’s environmentally friendly
Water percolates through into soil below.
May save material and labor
All of below
Three basic elements of concrete are?
Cement, water and aggregates
Rock like substance produced by Kiln is called
Clinkers
The four basic ingredients used to manufacture of cement are
Iron, silica, alumina and limestone
Normal porcelain cement is now known as?
GU cement
High early strength hydraulic cement is known? As
HE cement
LH cement is used for?
Low heat of hydration cement
Expansive cements cause concrete to?
Expand during setting
Good aggregate shapes should look like what?
Round and cubicle
Find aggregates are usually considered to be
Less than 5 mm
Good aggregates should be?
The clean hard and strong
An accelerator is an example of a?
Admixture
The masonry cement is best suited for foundation construction is?
Type s, type n, type m, type 10
Type M
A major greenhouse gas produced by cement industry is?
CO 2
A methodology to reduce the CO2 emissions during cement production is?
Decrease the amount of clinker used
Describe the steps to finish concrete once it’s been placed in the form?
Vibrate, strike off, float, wait for the bead water to evaporate, steel trovel
What is bead water?
Access water in the concrete mix not needed for hydration
How does concrete Harden and why is curing important?
Concrete hardens through a chemical reaction between water and cement. Curing making sure is there enough moisture to maintain the chemical reaction. 28 days of curing will allow concrete to reach its design strength
Concrete is 10 times stronger in compression or tension
Compression
What are the three fundamental properties that make concrete work with steel?
Thermal expansion is approximately the same for concrete and steel.
Cement pace and concrete bonds strongly to steal reinforcing
Concrete protects to steal against rust and corrosion
Reinforcing steel and concrete needs to overlap how much?
24 * the diameter of the bar
Calcium chloride should not be used as an accelerator in in cement that is when?
Reinforced with steel
Reinforce it still using a marine application should be
Coded with epoxy. Or made from beginning with steel or galvanized steel
There are four common shapes of concrete shell roofs.
What are they
Michelle roof has been built as thin as 50 mm.
Barrel, domes, hyperbolic paraoloids, folded plates.
What is used to make patterns in concrete?
Commonly used liners are made of rubber or plastic,
Brush hammering, sand and acid etching, or sandblasting
What is used to add to concrete to change its color even to make it pure white
Mineral oxide pigments
What is shot-crete (Gunnite)
Is the Portland cement concrete that is applied by pneumatic ally gun.
Can be used for restorative work on concrete structures damaged by weather or fire. They’re used on boat holes, landslide control facings for cliffs