Layout and construct formwork for slabs on grade

Question 1

What are deformed bars?

Answer 1

Bars with lugs for extra bond to the concrete

Question 2

List for grades of rebar steel

Answer 2

300 350 400 550

Question 3

What is the difference between yield strength and ultimate strength and rebar?

Answer 3

Yield is max load a bar should receive so the bar won’t be damaged
Ultimate is the load limit which steel bar breaks

Question 4

What diameter is a 10 MA 15 M and a 20 M bar

Answer 4

11.3 and 16.0 and 19.5

Question 5

Why does reinforcing need a minimum concrete coverage?

Answer 5

To minimize damage from corrosion on fire

Question 6

What are the minimum concrete cover requirements around Rebar concrete against earth, such as in footings

Answer 6

75 mm or 3 inches

Question 7

What are the minimum concrete cover requirements around rebar for concrete exposed to weather above ground such as a driveway

Answer 7

38 mm

Question 8

Where should re-Barbie placed in concrete members such as beans

Answer 8

On the tension face of the concrete where the cracking will start

Question 9

Why are trust bars sometimes used in continuous beams

Answer 9

To follow
The tension stresses

Question 10

Vertical bars in a basement wall should be placed near the___face of the wall

Answer 10

Inside

Question 11

Why should Slabs on ground have reinforcing placed no more than 50 mm down from the top, regardless of slab thickness

Answer 11

To keep any cracks that may develop tightly together at the surface

Question 12

Give an example of where reinforcement would be in compression

Answer 12

Column

Question 13

In welded fabric what does 152×152 times MW 9.1/MW9.1 stand for

Answer 13

The spacing and the wire size and the type of fabric

Question 14

List five advantages to using fibres for reinforcement in concrete

Answer 14

Corrosion resistance where resistance, improved, tensile strength, less drying, shrinkage, concretes more flexible without cracking

Question 15

List, two materials, fibre reinforcement is made from

Answer 15

Steel and poly propylene

Question 16

How much should Rebar be laughed at splices

Answer 16

300 mm

Question 17

When is regular Welding of rebar permitted

Answer 17

On large rebar

Question 18

What is the difference between a slab bolster and an individual highchair?

Answer 18

Slabs come in long lengths and cut to length as needed. Chairs are smaller.

Question 19

What are chairs made from?

Answer 19

Steel wire, plastic concrete blocks

Question 20

Welded wire fabric is spliced by lapping 200 mm

Answer 20

Tru

Question 21

Where are stirrups used?

Answer 21

Beams and grade beams

Question 22

What are column ties

Answer 22

Same as stirrups, but used in columns

Question 23

Name five items that cause stress in slabs on grade that may cause cracking of the slab

Answer 23

Drying shrinkage temperature changes nonuniform soil support under the slab moisture in the soil. Traffic loads.

Question 24

Describe columns, bile reinforcement

Answer 24

A continuous piece of rebar wound like a spring and is used to hold the vertical bars in place in Collom