Question 1

Which of the following elements does the American Concrete Institute (ACI) recommended concrete mix design method use to produce the ideal durable concrete suitable for a local environment?
1. Strength
2. Economy
3. Weather and chemical resistance
4. Wear resistance
5. Appropriate cement type

Accepted Answer

The ACI recommended concrete mix design method involves all of the listed elements to produce the ideal durable concrete suitable for a local environment. These elements are balanced by ensuring the designed concrete mix controls the proportions used, material quality, material handling, concrete placing and curing. ACI also recommends that the mix design be checked in the field using trial batches, and adjustments made when necessary.

Question 2

What is the required cement content of a concrete mix requiring 295 pounds per cubic yard (lb/yd³) of water, air content of 5%, 28-day compressive strength of 4,000 psi and a water/cement ratio of 0.48?

Accepted Answer

The required cement content of the concrete mix is 614.6 lb/yd³. Solution: Use the water/cement ratio equation to determine the required cement Weight of concrete = weight of water / (water/cement ratio) Given, Weight of water = 295 lb/yd³ Water/cement ratio = 0.48 Therefore, Weight of concrete = (295 lb/yd³)/ 0.48 = 614.6 lb/yd³

Question 3

Which of the following tests is used on a compacted cone of concrete to measure the loss of height?

Accepted Answer

A slump test is used on a compacted cone of concrete to measure the loss of height. Slump tests are conducted at the job site to evaluate the workability of fresh concrete used, and to ensure consistency between all the batches of concrete used on a project. The workability of a specific batch of concrete is affected by its wetness; drier concrete mixes are typically less workable than wetter mixes.

Question 4

Which of the following definitions best describe the "screeding" process used when casting concrete?

Accepted Answer

"Screeding" is the process used to level the top of the concrete after it is set in a form. As part of the finishing process, texture is added to concrete after it has started set. During the vibrating process, the concrete mix is stimulated in order to move it around the reinforcing bars and into voids.

Question 5

In which of the following documents is the design criteria used in the United States for structural steel building elements provided?

Accepted Answer

The design criteria used in the United States for structural steel building elements is provided in the AISC 360 manual. This manual is entitled: Specification for Structural Steel Buildings. AISC also offers guidance for designing steel structures in areas with high-seismic activity in AISC 341. It may be interesting to note that ASTM is now known as ASTM International, and is a recognized globally as a leader in developing consensus-based standards.

Question 6

The applicable safety regulations for erecting steel structures, including provisions for handrails, walkways, flooring, training, and other protective measures, are monitored and/or enforced by which of the following entities?

Accepted Answer

The applicable safety regulations for erecting steel structures, including provisions for handrails, walkways, flooring, training, and other protective measures, are monitored and/or enforced by OSHA, state safety agencies, and safety compliance officers. OSHA developed rules for steel structure erection that addresses major causes of injuries and fatalities in 2001 (29 CFR 1926). OSHA and state safety agencies can take legal enforcement action against violators. The Bureau of Labor Statistics can provide the latest information on the injuries and fatalities reported during the previous year.

Question 7

Steel that is used in building construction is composed of iron and which of the following alloying materials?

Accepted Answer

Steel that is used in building construction is composed of iron and carbon. The other elements (nickel, silicon, and boron) may be included in alloy steel, in addition to iron and carbon. The degree of alloy determines the steel's hardenability and corrosion resistance.

Question 8

The American Institute of Steel Construction (AISC) specifications for structural steel buildings requires designs to be based on provisions for which of the following methods?

Accepted Answer

The AISC specification for structural steel buildings requires designs to be based on provisions for LRFD and ASD. These requirements are specified in the AISC document 360-10 (effective June 22, 2010). The structural integrity requirements are based on the nominal strength (LRFD) or allowable strength (ASD), unless otherwise stated by the applicable local building code.

Question 9

Which of the following is not a common property of steel used in building construction?

Accepted Answer

Elasticity range of 20,000 to 28,000 ksi is not a common property of steel used in building construction. Typically, the elasticity of steel used in building construction ranges from 28,000 to 30,000 ksi. Commonly, an elasticity of 29,000 ksi is specified.

Quiz 16: Struct Materials

Which of the following elements does the American Concrete Institute (ACI) recommended concrete mix design method use to produce the ideal durable concrete suitable for a local environment? 1. Strength 2. Economy 3. Weather and chemical resistance 4. Wear resistance 5. Appropriate cement type

What is the required cement content of a concrete mix requiring 295 pounds per cubic yard (lb/yd3) of water, air content of 5%, 28-day compressive strength of 4,000 psi and a water/cement ratio of 0.48?