07 Reinforced Concrete Construction

Question 1

Any concrete which is transported through a hose or pipe by means of pump.

Answer 1

Pumped Concrete (Pumpcrete)

Question 2

Concrete production system which is delivered to the job site ready for placement.

Answer 2

Ready Mix

Question 3

The process of providing gentle motion in mixed concrete, just sufficient to prevent segregation of materials and loss of plasticity.

Answer 3

Agitation

Question 4

Any substance other than cement, water, or aggregate added to a concrete or mortar mix to alter its properties or those of the hardened product, also called additives.

Answer 4

Admixture

Question 5

An admixture that disperses entrained air to increase workability, and improve resistance to cracking.

Answer 5

Air Entraining Agent

Question 6

An admixture that hastens the setting and strength development of a concrete, mortar, or plaster mix.

Answer 6

Accelerator

Question 7

An admixture that slows the setting of concrete, mortar, or plaster mix in order to allow more time for placing and working the mix.

Answer 7

Retarder / Decelerator

Question 8

An admixture used for reducing tension of the mixing water in a concrete mix thereby facilitating the wetting and penetrating action of water.

Answer 8

Surface-Active Agent

Question 9

An admixture that reduces the amount of mixing water required for the desired workability. Lowering the water-cement ratio generally results in increased strength.

Answer 9

Water Reducing Agent / Superplasticizer

Question 10

An admixture of a pigment or dye is added to a concrete mix to alter or control its color.

Answer 10

Coloring Agent

Question 11

An admixture causing cement particles to separate by imparting like electrostatic charges, it prevents bleeding of water to the surface of the concrete.

Answer 11

Dispersal Agent

Question 12

An admixture that increases denseness of concrete surfaces which are subjected to rolling live loads and impact.

Answer 12

Concrete Hardener

Question 13

An admixture that renders concrete more impermeable.

Answer 13

Concrete Wateproof

Question 14

An admixture that improves bond between two concrete surfaces.

Answer 14

Bonding Agent

Question 15

An admixture that prevents cement paste from bonding to the surface and inhibits the setting of cement paste.

Answer 15

Set Inhibiting Agent

Question 16

An admixture that prevents the evaporation of water from concrete and allows it to be retained for hydration.

Answer 16

Surface Sealing Agent

Question 17

An admixture that causes a slight expansion in plastic concrete or mortar and thus reducing or eliminating voids caused by settlement.

Answer 17

Gas Forming Agent

Question 18

An admixture of abrasive material is used as topping to prevent slippery surfaces.

Answer 18

Non-skid Surface Agent

Question 19

An admixture that is sometimes used in structures where it is desirable to avoid high temperature or in structures exposed to seawater or water containing sulfates.

Answer 19

Pozzolanic Admixture

Question 20

Any of various hard, inert materials such as sand and gravel added to cement to make concrete or mortar.

Answer 20

Aggregate

Question 21

Consisting of sand having a particle size smaller than 1/4” (6.4 mm) and shall pass through a 3/8” (9.5 mm) sieve.

Answer 21

Fine Aggregate

Question 22

Consists of crushed stones, gravel, or blast furnace slag having a particle size larger than 1/4” (6.4 m). Specify the portion of aggregate that is retained on a No.4 (4.8 mm) sieve.

Answer 22

Course Aggregate

Question 23

A joint between adjacent parts of a building that permits their relative movement due to temperature changes.

Answer 23

Expansion Joint / Contraction Joint

Question 24

A joint where two successive placements of concrete meet.

Answer 24

Construction Joint

Question 25

A joint that allows movement between the concrete slab and adjoining columns and walls of a building.

Answer 25

Isolation Joint

Question 26

Joint that creates lines of weakness so that cracking that may result from tensile stress occurs along predetermined lines.1

Answer 26

Control Joint

Question 27

Formworks removal of Footings:

1. Massive Footings
2. Cantilever Footings
3. Slab Footings

Answer 27

1. Massive Footings - 1 day (24 hrs)
2. Cantilever Footings - 5 days (120 hrs)
3. Slab Footings - 5 days (120 hrs)

Question 28

Formworks removal of Walls and Plaster:

1. 0.30m thick or more
2. less than 0.30m thick
3. cantilever walls, buttresses, counterforts, diaphragms

Answer 28

1. 0.30m thick or more - 1 day (24 hrs)
2. less than 0.30m thick - 2 days (47 hrs)
3. cantilever walls, buttresses, counterforts, diaphragms - 2 days (48 hrs)

Question 29

Formworks removal for Columns

Answer 29

1 - 2 days

Question 30

Formworks removal for Slabs:

1. 0.91m (3 ft)
2. 2.13m (7 ft)

Answer 30

1. 0.91m (3 ft) - 5 days (120 hrs)

2. 2.13m (7 ft) - 7 days (168 hrs)

Question 31

Formworks removal for Beams and Girders:

1. side
2. bottom

Answer 31

1. side - 3 days (72 hrs)

2. bottom - 14 days (336 hrs)