Chapter 19 and 20 concrete quiz

3. Ultra high performance concretes utilize superplasticizers to reduce the water-cement ratio to less than

.2

Typical compressive strengths for structural lightweight concrete range from______

3000 psi to 5000 psi

What is the generic maximum temperature differential for mass concrete?

36 F

. For roller compacted concrete pavement applications, cement contents range from ____

400-600 pounds per cubic foot

. Insulating concrete is a lightweight concrete with an oven dry density of ____ of less

50 pounds per cubic foot

9. About _____ of ready mixed concrete has a 28 day specified compressive strength ranging from 3000 psi to 6000 psi.

90%

6. The time in which a specified strength for a high-early-strength concrete should be achieved may range from_____ to several days.

A FEW HOURS

7. High cementitious material contents, large dosages of admixtures, low water contents, and air entrainment all contribute to high-performance concrete being ______.

Difficult to finish

Current ASTM tests specifically for self-consolidating concrete test the flowing ability, the _____, and the dynamic and static stability.

passing ability

8. High performance concrete with low water to cement ratios can ______ to a level that does not allow alkali-silica reaction to occur.

self desiccate

2. High performance concrete has a very good resistance to carbonation due to it low permeability

true

The preplaced aggregate method of concrete construction reduces drying shrinkage

true

10. One benefit for using self-consolidating concrete is_____.

Its ability to be placed in congested areas

5. High performance blast resistant concrete often has a compressive strength exceeding_____ and contains steel fibers

14500 PSI

Previous concrete has a void concrete of approx. _______

15-35%

What is the maximum expected temperature rise of concrete moisture due to the heat of hydration of Type I Portland Cement?

16F per 100 pounds of concrete

. No slump concrete is defined as concrete with a consistency corresponding to a slump of ____ or less.

1/4"

The amount of color pigments added to a concrete mixture should not be no more than ____ of the weight of the cementitious material

10 %

1. Most high strength concrete applications are designed for compressive strengths of _____ or greater.

10000 psi

Of the following aggregates, which are used to produce high-density concrete?

Barite