Exam 2- the subject of masonery (stone,concrete,brick)

What is typical mortar made of?

The most common mortar is a cement-line mortar made of: Portland cement, hydrated lime, water, and an inert aggregate (sand that is cleaned and screened to eliminate particles that are too large or too small

What is mortar's purpose in masonry construction?

Mortar serves to (1) cushion the masonry units (giving them full bearing against one another despite their surface irregularities), (2) seals between the units to keep water and wind from penetrating, (3) adheres the units to one another to bond them into a monolithic structural unit, and (4) important to the appearance of the finished masonry wall (aesthetics).

What are the primary types of mortars, what are they used for, and what are the compressive strengths at 28 days?

Type M: high-strength with less workability than Type S or N - used for masonry construction below grade, masonry subject to high lateral or compressive loads, or masonry exposed to severe frost action. Compressive strength at 28 days: 2500 psi.

Type S: higher flexural bond strength than Type N - used for exterior reinforced masonry, exterior load-bearing masonry walls, and veneers and walls subject to high wind forces or high seismic loads. Compressive strength at 28 days: 1800 psi.

Type N: general-purpose mortar - used for exterior veneers, non-load-bearing exterior walls, parapets, chimneys, and interior load-bearing walls. Compressive strength at 28 days: 750 psi.

Type O: low-strength mortar - used mainly for interior non-load-bearing masonry and historic restoration work. Compressive strength at 28 days: 350 psi.

Type K: very-low-strength - used in historic preservation work that is no longer part of the ASTM C270 specification. Compressive strength at 28 days: not listed in reading.

What is a brick shaped and dimensioned to fit?

A human hand.

Also, hand-sized bricks are less likely to crack during drying or firing than larger bricks, and they are easy to manipulate.

Name and describe the three main processes used to mold bricks.

Soft Mud Process: (oldest process) relatively moist clay (20-30% water) is pressed into simple rectilinear molds, either by hand or with the aid of molding machines.

Dry-press Process: used for clays that shrink excessively during drying - clay mixed with a minimum of water (up to 10%) is pressed into steel molds by a machine working at a very high pressure.

Stiff Mud Process: high-production process most widely used today - clay containing 12-15% water is passed through a vacuum to remove pockets of air, then extruded through a rectangular die. As the clay leaves the die, textures or thin mixes of colored clays may be applied. The rectangular column of moist clay is pushed by the pressure of extrusion across a cutting table, where automatic cutter wires slice it into bricks.

What is the difference between water-struck bricks and sand-struck bricks?

Water-struck bricks: During the Soft Mud Process, to keep the clay from adhering to the molds, the molds may be dipped into water immediately before being filled, producing bricks with a relatively smooth, dense surface.

Sand-struck bricks: During the Soft Mud Process, the wet mold is dusted with sand just before forming the brick, producing a matte-textured surface.

What are the 12 most commonly used names (including their sizes) of bricks?

1. Modular brick

2. standard brick

3. engineer modular

4.engineer standard

5. utility brick

6.norman brick

7.roman brick

8. jumbo modular

9. king size brick

10. queen size brick

11. closure brick

12. paver brick

What is the standard size of a brick?

there is no standard size

What are the 3 most common brick classifications, their ASTM, and uses in building construction today?

Facing bricks (ASTM C216) - used for structural and nonstructural applications where appearance is important. Specified as a solid unit.

Building bricks (ASTM C62) - used where appearance does not matter, such as in backup wythes of masonry that will be concealed in the finished work. Specified as a solid unit.

Hollow bricks (ASTM C652) - may be up to 60% void and used to enable the insertion and grouting of steel reinforcing bars in single wythes of brickwork.

What are the qualities a designer must consider in choosing bricks for a building?

Color

Size

Molding Process

Grades (based on durability)

Compressive Strength

Brick Type (appearance uniformity)

Reinforcing needs

What are the 3 grades of facing brick, building brick, and hollow brick to select from when specifying brick in a building?

Grade SW: Any weathering region, all brick in contact with the earth

Grade MW: Aboveground brick in regions considered negligible weathering only per Figure 8.16 (Weathering Regions US Diagram)

Grade NW: Sheltered or indoor locations only

What are the 3 brick types for appearance uniformity?

Type FBX: Least variation in size per unit, least distortion in shape, minimum chippage

Type FBS: General-purpose face brick, with wider variation in shape and size, greater chippage

Type FBA: Great nonuniformity in size and shape permitted, as defined by the manufacturer

What is the difference between a wythe and a course in brickwork terminology?

Wythe: A single vertical layer of masonry units, one unit thick.

Course: A horizontal layer of bricks or other masonry units.

Which joints cannot be used in climates with heavy rainfall and snow?

raked joint

stripped joint

struck joint

What is a lintel, and what are the material types used in masonry construction?

Lintels support the openings for windows and doors in masonry walls. They may be reinforced concrete, precast concrete, reinforced brick, or steel angles.

When is corbelling used in masonry (brick or stone) construction?

The corbel is an ancient structural device of limited spanning capability used for small openings, beam brackets, and for ornament.

What is a spandrel in brick terminology?

The spandrel is the area of the wall that is bound by the extrados of the arch.

In masonry construction, building two ends/corners of a wall first before filling in the bricks between them is called ________.

laying the leads

What is the MasterFormat CSI/CSC Section for Masonry?

04 00 00

What is the MasterFormat CSI/CSC Section for Unit Masonry?

04 20 00

What is the MasterFormat CSI/CSC Section for Refractory Masonry?

04 50 00

What is a composite masonry wall?

Solid masonry walls of more than one wythe with an outer wythe of stone or face brick and a backup wythe of hollow concrete masonry. The two wythes are bonded together by steel horizontal joint reinforcing or steel ties. A composite masonry can be load-bearing or non-load-bearing.

What is the purpose of a cavity wall?

A cavity wall prevents water from reaching the interior of the building through a hollow space between the outside and inside wythes of a wall.

What are the two general types of flashing used in masonry construction and why are they used?

External Flashings: prevent moisture from penetrating into the masonry wall at its exposed top or where it intersects the roof.

Internal Flashings (concealed or through-wall flashings): catch water that has penetrated a masonry wall and drain it through weep holes back to the exterior.

What materials are flashings made from?

Sheet metal (most durable and expensive; copper and stainless steel are the best)

Modified asphalt membranes

Plastics

Rubbers

Composite sheets

What are the three general ways to insulate masonry walls?

On the outside face - by an exterior insulation and finish system (EIFS), which consists of panels of plastic foam that are attached to the masonry and covered with a thin, continuous layer of polymeric stucco reinforced with glass fiber mesh. Looks like a "stucco building".

Within the wall - (1) for wide cavities - slabs of plastic foam insulation can be inserted against the inside wythe of masonry as the wall is built, (2) the hollow cores of a concrete wall can be filled with loose granular insulation or with special molded-to-fit liners of foam plastic.

On the inside face - by rigid insulation attached with wood or metal furring strips to the inside wall with masonry nails or power-driven metal fasteners. Gypsum wallboard or other finish material is then fastened to the furring strips.

What are some of the "special problems" of masonry construction?

Expansion and Contraction - the need for movement joints

Efflorescence - a fluffy crystalline powder (often white) that sometimes appears on the face of a wall of brick, stone, or concrete. Water-soluble salts present in either the masonry units or mortar are brought to the surface by water.

Mortar Joint Deterioration - water running down a wall tends to accumulate in the joints, where cycles of freezing and thawing weather can gradually spall (split off flakes of) the mortar that eventually creates water leaks and loosens the masonry units.

Moisture Resistance of Masonry - due to the porous nature of masonry materials, water can be transmitted from the outside of the wall to the inside. Water can also enter through the cracks between the masonry units and the mortar and defects in the mortar joints.

Cold- and Hot-Weather Construction - the strength and water tightness may be damaged if allowed to freeze before it has cured. Mortar may dry excessively before it cures in hot weather.

What is the difference between an expansion joint and a control joint?

Expansion Joint: open seams that can close slightly to allow expansion to occur in adjacent areas of material.

Control Joint: deliberately created lines of weakness along which a crack will occur as a surface of brittle material shrinks, relieving the stresses that would otherwise cause random cracking.

What is the MasterFormat CSI/CSC Section for Dampproofing and Waterproofing?

07 10 00

What is the MasterFormat CSI/CSC Section for Flashing and Sheet Metal?

07 60 00

What is the MasterFormat CSI/CSC Section for Sheet Metal Flashing and Trim?

07 62 00

What is the MasterFormat CSI/CSC Section for Flexible Flashing?

07 65 00

How is building stone obtained?

Building stone is obtained by taking rock from the earth and reducing it to the required shapes and sizes.

What are the three geological classification types of stone (rock)?

Igneous rock: rock that was deposited in a molten state

Sedimentary rock: rock that was deposited by the action of water and wind

Metamorphic rock: rock that was formerly either igneous or sedimentary rock. Subsequently, its properties were transformed by heat and pressure.

ASTM C119 classifies stone into 6 groups. What are these groups called, and what are their properties and applications in building construction?

Granite Group: an igneous rock that is nonporous, hard, strong, and durable. It is suitable in locations exposed to severe weathering. (Requirements for granite dimension stone are defined by ASTM C615.)

Limestone Group: one of two sedimentary rock types used in construction. It may be found in strongly stratified form or in deposits that show little stratification (freestone). Can be classified as either I Low-Density, II Medium-Density, or III High-Density (ASTM C568).

Quartz-Based Dimensional Stone Group: Sandstone, brownstone, bluestone. It may be found in strongly stratified form or as more homogeneous freestone. Wide range of building applications (Requirements for quartz-based dimension stone are specified in ASTM C616.)

Slate group: a metamorphic stone group, which was formed from clay. It is a dense hard stone with closely spaced planes of cleavage - making it easy to split into sheets. Used for paving stones, roof shingles, and thin wall facings. (Requirements for slate dimension stone are specified in ASTM C629.)

Marble Group: a metamorphic rock and is a recrystallized form of limestone. It can be easily carved and polished, and comes in a wide variety of colors often with veining patterns. The Marble Institute of America has established a four-step grading system - A through D. A wide range of building applications - most commonly used in interiors. (Requirements for marble dimension stone are specified in ASTM C503.)

Other Group: this group includes a variety of stones less frequently used as building stones according to ASTM C119, such as - travertine (ASTM C1527), alabaster, greenstone, schist, serpentine, and soapstone. Travertine and soapstone are often found in interior applications, including wet areas. Soapstone can be used to radiate heat near fireplaces and in spa applications.

What are the different stone forms the construction industry uses?

Fieldstone: a rough building stone obtained from riverbeds and rock-strewn fields

Rubble: irregular quarried fragments that have at least one good side to expose in a wall

Dimension Stone: stone that has been quarried and cut into rectangular forms - large slabs are called cut stone and small rectangular blocks are called ashlar.

Flagstone: thin slabs of stone wither rectangular or irregular in outline that are used for flooring and paving.

Define stone masonry.

A method of construction where stone is laid in mortar, like bricks or blocks, to make walls, arches, and vaults.

Define stone cladding.

Stone that is mechanically attached to the structural frame or wall of a building face.

What are CMUs? What forms do they come in?

CMU stands for Concrete Masonry Units, which are manufactured in three basic forms - solid bricks, larger hollow units (concrete blocks), and larger solid units.

A CMU is nominally 8 inches high and 16 inches long (as a full block). What widths do CMUs come in?

4 inches

6 inches

8 inches

10 inches

12 inches

Concrete masonry units (CMUs) are steam-cured under high pressure in a chamber called:

an autoclave

How are CMU block walls reinforced?

Horizontally with steel joint reinforcing in a ladder or truss shape in the mortar between courses.

Vertically with rebar and grout.

Lintels for opening in concrete masonry walls are made from what materials?

Lintels support the openings for windows and doors in concrete masonry walls. They may be:

A steel lintel for broad openings is made up of a wide-flange section welded to a plate.

Reinforced concrete block composed of bond beam units filled with rebar and concrete.

Precast reinforced concrete.

Can a CMU block have a decorative face?

yes

What are examples of the other types of masonry units?

Structural glazed facing tiles (of clay)

Structural terra cotta

Glass blocks

Autoclaved aerated concrete (AAC)

What is the MasterFormat CSI/CSC Section for Masonry Grouting, Masonry Reinforcing Bars, and Stone Anchors?

04 05 00

What is the MasterFormat CSI/CSC Section for Clay Unit Masonry?

04 21 00

What is the MasterFormat CSI/CSC Section for Concrete Unit Masonry?

04 22 00

What is the MasterFormat CSI/CSC Section for Stone Assemblies?

04 40 00