Chapter 8

course

1) A horizontal layer of masonry units one unit high. 2) A horizontal line of shingles or siding.

air-entraining admixture

An admixture that causes a controlled quantity of stable microscopic air bubbles to form in concrete or mortar during mixing, usually for the purposes of increasing workability and resistance to freeze-thaw conditions.

running bond

Brickwork consisting entirely of stretchers.

common bond

Brickwork laid with five courses of stretchers followed by one course of headers.

masonry

Brickwork, concrete blockwork, and stonework.

How many syllables are in the word masonry? (Hint: There cannot be more syllables in a word than there are vowels. Many people, even masons & building professionals, mispronounce this word.)

3 ma-son-ry

stretcher

A brick or masonry unit laid in its most usual position, with the broadest surface of the unit horizontal and the length of the unit parallel to the surface of the wall.

masonry unit

A brick, stone, concrete block, glass block, or hollow clay tile intended to be laid in mortar.

Portland cement

A gray or white powder, composed principally of calcium silicates, which, when combined with water, hydrates to form the binder in concrete, mortar, and stucco.

masonry cement

A hydraulic cement made from a blend of Portland cement, lime, and other dry admixtures designed to increase the workability of the mortar.

lime

A non-hydraulic cementitious material, used as an ingredient in mortars and plasters.

mortar

A substance used to join masonry units, consisting of cementitious materials, fine aggregate, and water.

trowel

A thin, flat steel tool, either pointed or rectangular, provided with a handle and held in the hand, used to manipulate mastic, mortar, plaster, or concrete. Also, a machine whose rotating steel blades are used to finish concrete slabs; to use a trowel.

wythe

A vertical layer of masonry that is one masonry unit thick. (rhymes with 'scythe' and 'tithe').

cement-lime mortar

Mortar made from Portland cement, hydrated lime, aggregate, and water, the most traditional formulation of modern masonry mortars.

mason

One who builds with bricks, stones, or concrete masonry units; one who works with concrete.

What are the ingredients of mortar? What is the function of each ingredient?

Portland cement - bonding agent in mortar, gives strength and weather resistance. Hydrated lime - imparts workability Inert aggregate - superior mechanical qualities, high shear, tensile strength Water - chemically involved, portable, activates cement and lime

quicklime

Produced by burning calcium carbonate found in limestone or sea shells; once hydrated, used as an ingredient in mortars and plasters; chemically, calcium oxide.

Type M mortar is recommended for masonry construction below grade.

True

Type S mortar is recommended for exterior loadbearing walls.

True

What is the function of a structural brick bond such as common or Flemish bond?

to bond multiple wythes of masonry into a single wall.

List the functions of mortar.

to serve as a cushion to masonry units, to seal units to keep water and wind away, adhesive.

Why are mortar joints tooled? Which tooling profiles are suitable for a brick wall in a severe climate?

tooling gives a neat appearance and compact the mortar. Vee joints and concave joints are suitable for severe climate.

There is no truly standard brick size.

True

What are the molding processes used in manufacturing bricks? How do they differ from one another?

1) Soft mud process - oldest method. Moist clay pressed into rectangles. 2) Dry-press process - use mold clays that shrink excessively during drying. Machine works at high pressure little water 3) Stiff mud process - most used. Clay (12-15% water) passed through vacuum. Air present is removed then clay is extruded through a rectangular die. Automatic cutter wires slice the clay into bricks

Aggregate (sand) is the bonding agent in mortar.

False

Good workable mortar is typically composed of cement, sand, and water.

False

Solid bricks must be solid throughout their entire length and width.

False

Type I mortar is recommended for interior non-loadbearing applications.

False

blended hydraulic cement

Hydraulic cement made from a mixture of cementitious materials such as Portland cement, other hydraulic cements, and pozzolans for the purpose of altering one or more properties of the cement or reducing the energy required in the cement manufacturing process.

mortar cement

In masonry, a blend of Portland cement, lime, and other additives, that produces mortar comparable in its bond strength properties to cement‑lime mortar.

aggregate

Inert particles, such as sand, gravel, crushed stone, or expanded minerals, in a concrete, mortar, or plaster.

slaked lime, hydrated lime

Quicklime mixed with water, either in the factory or on the job site; an ingredient in masonry mortars, Portland cement plaster, and gypsum plasters, to which materials it imparts properties such as workability, bulk, and smoothness; chemically, calcium hydroxide;

Low-lift grouting is done in lifts no greater than 4 feet vertically.

True

Modular bricks are dimensioned so that three courses plus mortar joints add up to a vertical dimension of 8 inches.

True

Mortar has a life span that is limited to 2-1/2 hours.

True

structural bond

The interlocking pattern of masonry units used to tie two or more wythes together in a wall.

hydration

The process by which cements combine chemically with water to harden.

head joint

The vertical layer of mortar between ends of masonry units.

spandrel

The wall area between the head of a window on one story and the sill of a window on the floor above; the area of a wall between adjacent arches.

What are the most common types of masonry units?

bricks, stones, and concrete masonry units