Cosc Test 2 IM GONNA DIE

Portland cement ______ composition

Chemical

__________ and supplementary cementitious materials

Admixtures

Aggregate _______ and characteristics

Gradation

Mixture______ and _______ procedures

Design
Batching

Handling, placement and ______ procedures

consolidation

______ and development of the microstructure (curing)

Hydration

Name the 3 main basic ingredients for making concrete material. 

1.) Water

2.) Aggregate

3.) Cement (usually Portland cement)

The largest aggregate size should not exceed ______ of the spacing between steel reinforcement.  

3/4

A high water to cement ratio will results in a higher strength concrete. 

False

Portland Cement is grey in color because of the high calcium oxide content. 

False

The common maximum aggregate size for a coarse concrete aggregate is:

3/4 to 1-1/2 inch

A concrete coarse aggregate can be define as an aggregate material composed of particles greater than 4.75mm in size. 

True

A sand material can be considered as a fine aggregate for concrete making. 

True

Concrete is an impermeable material

False

Portland-lime cement production in the US now surpasses Type I/II cement production

True

If you can drink the water, its good for concrete making!

True

Portland cement is primarily manufactured from (select all that apply):

aluminates

calcium carbonates

iron oxides

silicates

Concrete is considered to be a non-combustible material. 

True

Blend raw materials are heated in a ______ to produce clinker.

Kiln

Clinker is cooled and mixed with talc to produce Portland cement.

False

Heat will initiates the chemical process of cement hydration  and causes the concrete mix to harden

False

Recycled glass can be used as a concrete aggregate

True

Construction of a sidewalk in College Station TX.

Type 1

Sidewalk in Burlington Vermont during February

Type 3

Reinforced concrete building on campus during the Fall.

Type 1

Concrete dam in Colorado state during the Summer.

Type 4

Columns for ocean front pier in Galveston

Type 2

Foundation footings in contact with soil having a sulfate concentration of 3489 ppm

Type 5

Fast track construction of parking garage in Dallas.

type 3

Set retarders are a commonly used admixture to improve the freeze-thaw durability of concrete. 

False

Calculate the amount of concrete needed (in cubic yards) to pour a 10 inch thick slab. The dimensions of the slab are 25 feet by 25 feet.

20

High-strength concrete is desirable for use in fast-track construction to achieve higher earlier strength.

True

Conventional or normal strength concrete is typically below 6000psi at 28day strength. 

True

Select all that apply for the use of SCMs in concrete. 

Increased strength

Changes the setting rate.

 Lowers the embodied carbon of concrete

 Improved workability

 Increased durability

 Decreased heat of hydration

Rule of thumb,  a standard concrete material cannot be placed beyond 90 minutes after mixing commences. 

True

Admixtures are added ingredients that alter or improve a specific property of either fresh or hydrated concrete.

True

Water reducers are commonly used to reduce the water content of concrete mixture thus diminishing the w/c of the mix. 

True

High strength concrete is made using standard concrete materials and seldom requires the use of admixtures nor SCMs

False

Concrete strength varies with the design of the mixture and its ingredients.

True

Concrete is strong in tension. 

False

Typically finishing steps start before surface bleeding starts. 

False

A compression test is performed on prism specimens. 

False

Select all that apply. Curing involves

misting the surface with water

protecting the surface with a cover

leaving the form in place for several days

Seal the surface with chemical sealers

The goal of consolidating concrete is to remove entrapped air in concrete preventing air voids within the concrete once hardened. 

True

Conventional or normal strength concrete is typically below 6000psi at 28day strength. 

True

Select all that apply, if a physical barrier is present on-site, concrete can be placed with the aid of:

power buggies

Pump truck

crane-lifted buckets

Construction joints to minimize cracking can be prepared during finishing steps. 

True

Select all that apply.  Common methods used for consolidating concrete are:

Vibration

Rodding

Tamping

During finishing of concrete, surface textures are not of importance, only ensuring that the concrete is flat is of importance. 

False