Question 1

Which of the following statements is true regarding water used in mortar?
A) It should be high in alkalis but low in salts.
B) It should be high in both salts and acids.
C) Purifying chemicals in city water supplies have an adverse effect on mortar.
D) Water fit to drink is acceptable for use in mortar.

Accepted Answer

Water fit to drink is acceptable for use in mortar. Using water that is too high in alkalis or salts can lead to efflorescence, a white crystalline deposit that forms on the surface of masonry. Purifying chemicals added to city water supplies typically do not affect the quality of water for mortar mixing.

Question 2

Good quality sand is available in only one type: manufactured.

Accepted Answer

Good quality sand can also be found in natural sources such as ocean beaches, riverbanks, and deserts. However, the availability and quality may vary depending on the location and extraction method.

Question 3

Which of the following statements is true about sand?
A) Manufactured sand is smoother than natural sand.
B) Natural sand has a sharp, angular grain shape.
C) Natural sand is rounder than manufactured sand.
D) Manufactured sand is very high in salt content.

Accepted Answer

Natural sand is typically rounder due to the erosion process it undergoes over time, unlike manufactured sand which is produced by crushing rocks and can have sharper edges.

Question 4

The ability of mortar to reknit or reseal itself if hairline cracks occur is called _____ .
A) flexibility
B) autogenous healing
C) compressive strength
D) adhesion

Accepted Answer

Autogenous healing is the correct term to describe the ability of mortar to reknit or reseal hairline cracks. Flexibility refers to the ability of a material to bend or stretch without breaking. Compressive strength refers to the ability of a material to resist compression, while adhesion refers to the ability of a material to stick to another surface.

Question 5

The production of portland cement involves only one simple process.

Accepted Answer

The production of portland cement involves multiple complex processes including quarrying, mixing raw materials, heating, and grinding.

Question 6

_____ portland cement is used in masonry when moderate sulfate resistance or moderate heat of hydration is desired.
A) Type A
B) Type B
C) Type I
D) Type II

Accepted Answer

Type II portland cement is recommended when moderate sulfate resistance or moderate heat of hydration is desired. Type A is used in general construction where the rate of strength development is important, Type B is suitable where high sulfate resistance is required and Type I is a general-purpose cement that can be used for a variety of construction projects when no other specialized properties are needed.

Question 7

ASTM C1329 applies to ______, a hydraulic cement similar with the added requirement of meeting a minimum bond strength.
A) blended hydraulic cement
B) mortar cement
C) masonry cement
D) portland cement

Accepted Answer

ASTM C1329 is specifically applicable to mortar cement, which is a hydraulic cement similar to masonry cement but with the added requirement of meeting a minimum bond strength.

Question 8

Clay was the first material to be used for mortar.

Accepted Answer

It is true that clay was the first material used for mortar.

Question 9

ASTM C150 covers _____ types of portland cement, but only _____ are recommended for use in masonry mortars.
A) four; two
B) five; four
C) seven; five
D) eight; three

Accepted Answer

ASTM C150 covers eight types of portland cement, but only three are recommended for use in masonry mortars.

Question 10

A _____ will usually be classified as Type M, Type S, or Type N.
A) blended hydraulic cement
B) mortar cement
C) masonry cement
D) portland cement

Accepted Answer

Masonry cement is classified as Type M, Type S, or Type N, which are designations for different strength levels and uses in masonry construction.

Question 11

Portland cement is a _____ cement, which means that it sets and hardens by a chemical reaction with water.
A) hydraulic
B) natural
C) hydrated
D) lime-sand

Accepted Answer

Portland cement is a hydraulic cement, which means that it sets and hardens by a chemical reaction with water. This reaction is referred to as hydration and it produces a solid, durable material that is used in a wide range of construction applications. Natural cement is another type of cement that is made from naturally occurring materials, but it is not typically used today. Lime-sand cement is a mixture of lime, sand, and water that is used in certain specialized applications, but it is not a type of Portland cement.

Question 12

_____ is formed by calcining pieces of limestone under controlled heat.
A) Slaked lime
B) Quicklime
C) Hydrated lime
D) Hydraulic lime

Accepted Answer

Quicklime is formed by calcining pieces of limestone under controlled heat. Slaked lime, hydrated lime, and hydraulic lime are all produced through further processing of quicklime.

Question 13

Mortar performance is greatly influenced by the choice and amount of cement materials in the mix.

Accepted Answer

The statement is true. The choice and amount of cement materials directly affect the strength, workability, and durability of mortar. Different types and proportions of cement, such as Portland cement or hydraulic lime, can affect the setting time, compressive strength, and resistance to weathering and other environmental factors. Improper selection or insufficient amount of cement can result in poor performance and failure of the mortar.

Question 14

Lime-based mortar is high in _____, which means that the mortar resists drying effects when combined with the masonry Chapters to build a wall.
A) water retentivity
B) bond strength
C) workability
D) tensile strength

Accepted Answer

Lime-based mortar has high water retentivity, meaning it can resist drying effects when combined with the masonry and will retain moisture longer. This helps enhance the bond strength between the masonry units and the mortar.

Question 15

Although not as strong as previous cements, portland cement is less expensive and therefore more widely used.

Accepted Answer

Portland cement is actually the most common type of cement in general use around the world because it provides a more durable concrete, not because it is less expensive. Its widespread use is due to its versatility and strength, not its cost.

Quiz 12: The Development of Mortar

Which of the following statements is true regarding water used in mortar?

Good quality sand is available in only one type: manufactured.

Which of the following statements is true about sand?

The ability of mortar to reknit or reseal itself if hairline cracks occur is called _____ .

The production of portland cement involves only one simple process.

_____ portland cement is used in masonry when moderate sulfate resistance or moderate heat of hydration is desired.

ASTM C1329 applies to ______, a hydraulic cement similar with the added requirement of meeting a minimum bond strength.

Clay was the first material to be used for mortar.

ASTM C150 covers _ types of portland cement, but only _ are recommended for use in masonry mortars.

A _____ will usually be classified as Type M, Type S, or Type N.

Portland cement is a _____ cement, which means that it sets and hardens by a chemical reaction with water.

_____ is formed by calcining pieces of limestone under controlled heat.

Mortar performance is greatly influenced by the choice and amount of cement materials in the mix.

Lime-based mortar is high in _____, which means that the mortar resists drying effects when combined with the masonry Chapters to build a wall.

Although not as strong as previous cements, portland cement is less expensive and therefore more widely used.