1

20問 • 1年前

問題一覧

A mixture of water, cement, sand, gravel, crushed rock, or other aggragates The aggregates are held together in a rocklike mass with a paste of cement and water

concrete

This material is composed of geological materials such as gravel, sand and crushed rock

aggregate

Concrete has a high ______ but have a very low ______, usually ______

compressive strength, tensile strength, 1/10 of compressive strength

It is the maximum stress that a material can withstand while being stretched or pulled before breaking

tensile strength

Resistance of materials from being compressed or crushed

compressive strength

Aggregate that has smaller particles

fine aggregate

Aggregate that has bigger particles

course aggregate

Fine aggregates are those that passes through a no. 4 sieve (about ______ in size) Materials retained are ______

6 mm, course aggregates

It is the structure, usually temporary, used to contain poured concrete and to mould it to the required dimensions and support until it is able to support itself

formwork

Maximum sizes of course aggregate (largest individual stone in a batch) specified in ______: formwork slabs cs (beams columns slabs)

section 5.3.3 of NSCP 1/5 of the narrowest dimension between sides of forms 1/3 depth of slabs 3/4 of minimum CS between individual reinforcing bars or wires

Tool used to separate different sized particles in concrete materials, such as aggregates, soil, and asphalt

sieve

It is used to reinforce concrete to increase its tensile strength

reinforcement bars (rebars)

Seawater cannot be used in mixing concrete because ______

salt corrodes steel bars

According to section 5.3.4 of NSCP:

water used in mixing concrete shall be clean and free from substances that may damage the concrete or its reinforcement (oils, acids, alkalis, salts, organic materials, etc.)

Aluminum can be embedded in concrete, but ______ To avoid this, ______

(1) it can corrode and crack the concrete (2) aluminum must be covered with corrosion-resistant coatings to act as a barrier between the aluminum and concrete — epoxy coatings — galvanization — nonreactive plastic or PVC (polyvinyl chloride)

It can be used in concrete as a reinforcing material, aggregate, or to encase concrete

polyvinyl chloride (PVC)

These are structural elements placed within concrete during the pouring process (steel plates, pipes, ducts, anchors, etc.)

concrete embedments

It is the process of applying a protective layer of zinc to steel or iron to prevent rust

galvanization / galvanizing

Non-potable (non-drinkable) water shall not be used in concrete unless the following are satisfied:

(a) use the water first to design the right proportion of materials to mix in making the concrete to make the concrete strong, even when non-potable source is used (b) the mortar test cubes' strength made with non-potable water must be equal or greater than 90% of the strength of mortar test cubes made using potable water

It occurs when the heavy aggregates settle down due to gravity, leaving behind the lighter cement and water mixture on top

segregation

EM Waves and Spectrum

John Marabiles · 73問 · 1年前

EM Waves and Spectrum