columns must be what? to prevent racking

What are examples of prestressed concrete?

When casting stairs, or stepped footings begin concrete placement?

When concrete is exposed to moderate sulphate attack what type of cement is recommended?

Compressive strength are measured by ?

For underwater placement of concrete?

Raking concrete with the tines down can cause?

Always place concrete (location)

What type of mixer would be more suitable then transit mix for remote location ?

The chemical reaction between water and cement is called ?

Excessive vibration can cause

Monolithic toppings are installed while ?

Concrete is strong in what? but weak in?

If a strike off board won’t reach from edge to edge ?

The maximum size of aggregate, when pumping ?

Air entrainment increases the ability of concrete to withstand ?

What does vibration of concrete do?

When aggregates are well, graded and economical mix is achieved because less what is required ?

The recommended maximum allowable placement time for concrete is ?

Self levelling concrete is used to create a ?

When curing with poly in the winter, what colour is preferable?

To check for the presence of an organic material what test is done?

What is added to cement to regulate the setting time of concrete?

Concrete cast without reinforcement is called ?

The test used to test the slump or self consolidating concrete is called ?

the reaction between concrete and carbon dioxide is called?

when pouring a floor with heating ducts cast it is important to?

Sandblasting of concrete surface should not exceed ?

Factors affecting hydrostatic pressure for concrete are ? (4 factors)

Cement (concrete) is made out of? (Lisag)

What compacts and densifies the concrete surface, making it smoother and stronger ?

When grouting in post tensioning ducts, it is best to use what type of grout ?

Aggregates account for what percent of concrete volume ?

What size is coarse aggregate?

bullfloats will bring paste to the surface, and ?

at 20 degrees concrete will set up in?

Improper curing can result in ? (strength loss)

Concrete used for skate parks pools and boat hulls is called ?

Slope can be expressed as ?

If wet curing is not done ?

Masonary concrete is considered ?

What size is fine aggregate ?

When heat curing, heat must be reduced by no more than ?

What types of concrete would be used for pours in hot weather?

It’s best to set wall pour Heights after ?

Concrete should always be placed ?

Concrete should not be allowed to fall freely more than ?

The recommended Max slump for a cast in place concrete walls and columns is ?

concrete curing begins?

Bronze and magnesium tools will aid in?

The most important thing when pour watching is?

Cast in place refers to concrete ?

Precast concrete is suited for structures where what is required

moistening the subgrade prevents?

Direct fired heater will cause ?

Wet screeds are fast and efficient and use ?

Normal density concrete weights ___lbs per cubic foot or ____kg per cubic meters

Floating should commence as soon as?

Hardeners are used for ?

Sandblasting should be done between

a low w/c will result in higher ___________ strengths?

Expansion joints would be installed at ?

A creamy Portland cement sand mixture is an example of ?

concrete must be poured? (hours)

Concrete should always be cast against fresh concrete to minimize?

Air entrainment percentage, when concrete arrives to site is usually what? What do we need to bring it up to after it arrives?

Wood floats should only be used on?

A metallic Hardner is ?

A Groover is used for?

Stakes and slab forms are cut ?

What type of walls are made up of tilt up concrete panels?

Overworking concrete will bring ?

vibrator penetration into the previous lift when pouring a wall is?

Vibratory screeds will ?