CMGT-121 Study Guide #1 Chapters 1 & 2

Pavement Layers:** (from bottom to top)

1st: Sub-Grade 2nd: Sub-Base 3rd: Base Layer 4th: Asphalt Surface

According to the U.S. Green Building Council, buildings account for

30% to 40% of the world's energy use and associated greenhouse gas emissions.**

Slurry Seal:

A thin asphalt overlay applied by a continuous process machine over worn pavement to seal them and provide a new wearing surface.

Making Buildings

A/ Learning to Build B/ Sustainability C/ The Work of the Design Professional

Aggregate Strength:

As a vertical load from the top is transmitted deeper, through points of contact, the load is spread over an ever larger area, with ever smaller forces at deeper levels: ~ Well-graded aggregate is stronger than not well-graded aggregate. ~ The larger the maximum size of aggregate is, the greater the strength. ** ~ The more flat, broken faces the particles have, the greater the strength developed through interlocking* ~ Compaction, especially by vibration, increases the shearing strength of aggregate of any size, shape, and gradation. ** ~ Rough particle surfaces increase strength because of greater friction between them.

Asphalt Cutbacks & Asphalt Emulsions

Asphalt is modified into two different liquid forms called:

Asphalt Cements:

Asphalt is produced from crude oil by fractional distillation.** The oil is heated, the lighter oils vaporize, and are drawn off, leaving a residual material—asphalt cement.

Gantt charts:

Bar charts

Other Uses of Asphalt:

Because of the preservative and waterproof characteristics of asphalt, it is used in: ~ roofing products ~ pipe coatings ~ automotive under-coatings ~ slope stabilizing mulch treatments ~ joint materials used to fill joints and crack in pavements and other structures.**

Foundations on clay or silt

Can settle a great deal

CSI

Developed a comprehensive outline called MasterFormat for organizing information about construction materials and systems. It is organized into 50 primary divisions.

ANSI

Develops and certifies standards for construction products

Sequential Construction:

Each major phase in the design and construction of a building is completed before the next phase begins.

Learning to Build

Economics often decides which building materials will be used. What costs less at first may cost more throughout its life cycle through maintenance and replacement, or energy use.

Building Fire Prevention Location/Setbacks:

For IRC, no openings in walls < 3 ft. to lot line, except for wall openings perpendicular to lot line; facing dwelling and structures on same lot; exempt accessory structures; foundation vents. Also openings are allowed up to 25% of wall area > 3 ft. but ≤ 5 ft. (unlimited if automatic sprinkler system present). Projections (eaves) a minimum of 5 ft. from lot line except for: 2 ft. okay if 1-hour fire protected on underside; 3 ft. okay if automatic sprinkler stems present; 4 ft. okay in detached garage if 2 ft. from lot line. IBC exceptions are more involved. [IRC Ch#3 and IBC Ch#7

Compaction generally

Generally increases strength of aggregates, reduces settlement, and improves bearing capacity. ** Well graded aggregates compact more easily than poorly graded aggregates.

Asphalt Testing (of Asphalt Cements):

Generally, tests performed on asphalt will measure consistency, durability, rate of hardening, serviceability, and the ability to be effective in hostile environments (like Louisiana). Asphalt is a thermoplastic material that changes viscosity with changes in temperature, so these tests are set at specific temperatures.**

Land Aggregate Sources:

Glacier deposits, former lake and river beds, bases of rock faces, or blasted/excavated rock mined by bucket loaders, power shovels, draglines, or power scrapers (after stripping topsoil) Aggregate is then washed, crushed if necessary, then sorted with grates, screens/sieves.

Crushed Gravel:

Gravel created by artificial crushing - with at least one face resulting from fracturing

Bank Gravel:

Gravel found in natural deposits, usually intermixed with fine material

Asphalt Safety - Heat:

Hot asphalt can easily be several hundred degrees, so it can cause severe burns to the skin.

Establishing the Design Flood Elevation:

In flood hazard areas, determine design flood elevation. [IRC Ch#3 and IBC Ch#16]

Wind Design Criteria:

In special wind hazard areas expecting over 110 mph, according to basic wind speed tables in the code, special design considerations are required. [IRC Ch#3 and IBC Ch#16]

IBC stands for:

International Building Code

IPC stands for: UPC stands for:

International Plumbing Code Uniform Plumbing Code

IRC stands for:

International Residential Code

Types of Asphalt Pavement Construction:

Plant Mix Road Mix (Mixed-in-Place) Slurry Seal Asphalt Spray Applications

Asphalt Spray Applications:

Prime Coats and Tack Coats are used to bond asphalt layers other layers or to base materials.**

Asphalt Cutbacks are classified as:

Rapid Curing (RC), Medium Curing (MC), and Slow Curing (SC), with a viscosity rating in "centistokes" where a higher number is more viscous

Construction Scheduling:

Requires a detailed understanding of the tasks required and their interdependencies. Planning and scheduling involves analysis of these relationships between the different project activities using Gantt charts (bar charts) and Network Diagrams (flow charts) to understand which activities are bottlenecks to progress. These bottlenecks are considered critical activities. A critical path can be charted through the project where these critical activities are focused, to keep the project on schedule.

Sources of Aggregates:

Sand and gravel banks occur from nature processes of parent rock broken mostly by temperature changes and transported and worn down by glaciers, gravity, wind, and water. The two basic sources are: underwater & land

Foundations on bedrock

Settle a negligible amount

Aggregate Safety - Silica Dust:

Silicon is the eight most common element, and the most common metalloid. Silica (silicone dioxide or SiO2). Inhalation of crystalline silica dust leads to reduced lung capacity, and eventually silicosis, bronchitis, and lung cancer. You are exposed to this dust in sand, gravel, clay, and cement powder. Even sweeping a warehouse floor can become a serious exposure.

NEC stands for:

National Electrical Code

Road Mix (Mixed-in-Place):

Often used for lower layers, Liquid Asphalt (either Cutback or Emulsion) is mixed or sprayed on-site, eliminating the need for a central mixing plant. A Road Mix is NOT heated.**

Soldier Beams and Lagging:

Steel columns called H-piles or soldier beams are driven vertically into the earth at small intervals (12-feet) around an excavation before excavation begins. As earth is then excavated, the lagging (usually heavy wood planks) is placed inside the flanges of the columns. This is really just a special type of sheet piling.

Crushed Stone:

Stone created by artificial crushing - with all faces resulting from fracturing

Bituminous Material - Tar:

Tar is generally produced as a byproduct during the production of coke (not the drink). It is not very soluble in carbon disulfide (or most petroleum products). Tar has little bitumen content (a type of hydrocarbon).**

Plant Mix:

The Asphalt Cement and Aggregate are heated separately from 250°F to 325°F in a plant**, mixed together and hauled to the jobsite, spread and compacted by rollers before it cools. It is called Hot Mix Asphalt (or HMA)

Compaction:

The densification of a material resulting in an increase in weight per unit volume

Compaction is

The densification of a material resulting in an increase in weight per unit volume.

Single-Purpose Entity

Owner designs, constructs, and finances project

Design/Build

Owner hires one entity that provides both design and construction services

Paying for Construction - Fixed fee (lump sum)

Owner pays general contractor an agreed, fixed amount for work performed

Paying for Construction - Cost plus a fee

Owner pays general contractor costs plus a fee

Design/Bid/Build

Owner separately hires design team and construction team

Some types of Asphalt Testing are:

Penetration test Viscosity test Flash-point test Thin-film oven test Ductility test Solubility test

Bituminous Material - Asphalt:

Petroleum Asphalt is the basic paving material (used along with aggregates). It is a cementitious material, solid or semisolid, with large bitumen content** so it is quite soluble in carbon disulfide (and many other petroleum products).

Asphalt Paving-Mix Design:

The quality of the asphalt paving mix design influences the required thickness.

Shrinkage

The reduction in volume when loose material is placed and compacted (as fill) on a project, it will be compressed into a smaller volume than when it was loose. And with the exception of solid rock, it will occupy less volume than in its bank condition.

Course Aggregates:

The same as Gravel for most purposes Aggregate that is retained on the No. 4 sieve (4.76-mm or about 3/16-in.)

Fine Aggregates:

The same as Sand for most purposes Aggregate that passes through the No. 4 sieve and is retained on the No. 200 sieve (74-microns)

LEED

The standard for measuring the sustainability of construction

Estimating Asphalt Concrete:

The unit of measure for the purchase of asphalt concrete is the ton (2000#). Each cubic foot of asphalt concrete weighs about 150#, so when you calculate the volume of material needed, you can then figure out how many tons needed, using this fact (150# = 1 cu. ft.)

Traffic Analysis:

The weight and volume of traffic that a road will carry influences the required thickness.

Aggregate Safety - Weight:

Typical aggregates used in construction weigh about 105 pounds per cubic foot (ranging from about 90# to 120#).

Shrinkage is expressed as

a percentage of the undisturbed original (or bank) volume

Asphalt Cutbacks are produced by:

dissolving the cement into a solvent

Asphalt Surface (asphalt-aggregate mix) Pavement Layer

is laid on top of all of other layers

Uncompacted excavated material is referred to as:

loose cubic yards (lcy)

Sub-Base Pavement Layer

of better quality aggregate is often layered on top of the sub-grade

Base Pavement Layer

placed on top of these layers made of a well-graded limestone road-building aggregate mix, or an asphalt-aggregate mix, or even portland cement concrete

Shotcrete:

pneumatically applied (air pressure) zero-slump concrete from a hose onto the steep slope to stabilize and prevent erosion.

Sub-Grade Pavement Layer

ultimately carries all traffic loads, so it must be prepared and structurally sound

Work Exempt from Permit:

~ 1-story accessory structures ≤ 200sq. ft. (IRC) (≤ 120 sq. ft. for IBC ~ Fences ≤ 7 ft. high ~ Retaining walls ≤ 4 ft. from bottom of footing to top of wall ~ Water tanks on grade ≤ 5000 gallons ~ Sidewalks; driveways; finish work like painting, cabinets, countertops, or flooring ~ Decks ≤ 200 sq. ft. and ≤ 30 in. above grade and not servicing required exit door (IRC). [IRC Ch#1 and IBC Ch#1]

Excavation: Two basic methods to prevent collapse are:

~ Excavation Shoring ~ Excavation Sloping

Building a road for all-weather use by vehicles is to prepare a suitable sub-grade or foundation, provide necessary drainage, and construct a pavement that will do the following:

~ Have sufficient strength to carry expected loads ~ Prevent moisture from penetrating or accumulating internally ~ Have a surface that is smooth and resistant to wear, distortion, skidding, and deterioration

Building Codes:

~ International Residential Code (IRC) 1 & 2 family buildings, up to 3 stories ~ International Building Code (IBC) building code for all other buildings ~ National Electrical Code (NEC) - NFPA 70 ~ International Plumbing Code (IPC) or Uniform Plumbing Code (UPC)

Two most common types of shoring or slope support are:

~ Soldier beams and lagging ~ Sheet piling: **

Properties/Qualities of Aggregates:

~ Weight (density) ~ Resistance to Weathering (especially freezing/thawing) ~ Compressive Strength, Tensile Strength, and Abrasive Resistance ~ Adhesive and Cohesive (frictional)Qualities ~ Permeability of the Mass (to allow water to flow through

Compacted material is referred to as

compacted cubic yards (ccy)

Design professional's develop the building plan for:

- An effective design - To comply with the legal constraints

Some types of legal constraints:

- Zoning Ordinances - Building Codes - American Disabilities Act (ADA) - Fair Housing Act - EPA - OSHA

Turnkey

Design/Build but includes financing

Pavement thickness range:

1" for driveways to 10" for highways**

Fast Track or Phased Construction:

Aims to reduce the time required to complete the project by overlapping the design and construction of various project parts.

ANSI stands for:

American National Standards Institute

ASTM stands for:

American Society for Testing and Materials

Approval of Construction Documents:

Approved plans and permit must be kept at the site of work. [IRC Ch#1 and IBC Ch#1]

CSI stands for:

Construction Specification Institute

Asphalt Safety - Flammability

Cutback liquid asphalt contains flammable solvents that can cause fires and explosions.

EPA stands for:

Environmental Protection Agency

ASTM

Establishes specifications for materials and methods

Network Diagrams:

Flow charts

Sustainability

Meeting the needs of the present generation without compromising the ability of future generations to meet their needs.

Underwater Aggregate Sources:

Lake and river bottoms mined by barge-mounted dredges with single scoops or an endless chain of scoops, by a draglines, or by pumps similar to those used for pumping concrete. Aggregate is then washed, crushed if necessary, then sorted with grates, screens/sieves

LEED stands for:

Leadership in Energy and Environmental Design

Bank Material:

Material in its natural state, measured in bank cubic yards (bcy)

Zoning Ordinance Regulations

Through local municipal government, building permits control land use, limit the size, type, and density of the structure that may be built

Sub-grade Evaluation:

Through testing and soil analysis, the strength of the sub-grade influences the required thickness.

Environmental Regulations

Through the Environmental Protection Agency (EPA)

Safety Regulations

Through the Occupational Safety and Health Administration (OSHA)

Liquid Asphalts:

To eliminate the need for heating asphalt to a liquid state, asphalt is modified into two different liquid forms (Asphalt Cutbacks and Asphalt Emulsions):**

Some factors that are considered for structurally sound pavement bases:

Traffic Analysis Sub-grade Evaluation Asphalt Paving-Mix Design

Sheet Piling:

Vertical planks of wood, steel, or precast concrete are placed tightly against one another, and driven into the earth to form a solid wall before excavation begins.

Swell

When bank material is excavated, the particles of earth are disturbed, and begin to swell. This expansion causes the soil to assume a larger volume. This expansion represents the amount of swell and is expressed as a percentage gained above the original volume.

Foundation - Uniform Settlement

When foundation settlement occurs at roughly the same rate throughout all portions of a building, (usually on uniform soil)

Foundation - Differential Settlement

When settlement occurs at differing rates between different portions of a building, (usually on differing soil or with unequal building loads)

Asphalt Emulsions are produced by:

separating the hot cement into tiny globules and dispersing them in water that has been treated with an emulsifying agent

In typical pavement construction, the load spreads over an area that increases with depth. Therefore,

the unit stress is less at greater depths. The material is arranged to be weaker and less expensive at greater depths. **