Concrete terms

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Reinforcement is typically done with bars

#3 bars, #5 bars... number represents the diameter in 1/8ths of inches #n, n/8ths of inch..... #3 = 3/8ths of inch

shallow foundations

(spread foundations) are the type that transfer the building loads directly to the sufficient soil area.

5 ways to transport concrete to formwork

1. chutes 2. push buggies 3. buckets handled by cranes 4. pumping through a pipeline (pump truck) 5. Pneumatically forcing through a hose - shotcrete

Process of making portland cement

1. made of pulverized lime, silica, alumina and iron 2. mix limestone with clay, shale or slag 3. heat mixture to 2700° F 4. fuse mixture to make clinker (.75" rocks) 5. clinker pulverized with gypsum 6. powdery substance created

Compression strength of concrete range from

2500-19,000 PSI The structural engineer determines the compressive strength of the concrete If you have a light building the foundation doesn't need to be as strong as a steel building

How long do you have to deliver and discharge concrete at a building site

90 minutes for according to ASTM C94

Main specification for portland cement

ASTM C150

Air Entraining

Adding more air to the mix

ASTM

American Society for Testing and Materials

Steps of finishing concrete

Bleeding -water rising to the concrete's surface Screeding - moving a straightedge back and forth over surface Leveling - bringing concrete to the desired level Edging - smoothing the edge to prevent chipping Jointing Floating - Floating is done when the water sheen has disappeared and the concrete will support the weight of the finisher Troweling - Create a smooth surface

C-C

Center to center

Form Liners

Chosen by architect, because its an aesthetic element. Cast in place; you have to build the forms which takes time The exterior finish takes the finish of whatever the form work is made out of Permanent: you leave the form in place; the earth( grade beam), insulated concrete forms (IFC) Temporary: pull the form away; sidewalks, walls

Type 2 Slab on grade

Contains wire welded fabric + some reinforcing bars Resists some differential soil movement Minimum of 4" thick Ex: driveways, pool decking

Why does concrete need to be consolidated

Eliminate stone pockets and large air bubbles consolidate each layer with the previous embed reinforcing bring just enough fine material to the faces and top surfaces to produce the desired finish

ECC

Engineered Cementitious Composite (ECC), also called bendable concrete, is an easily molded mortar-based composite reinforced with specially selected short random fibers, usually polymer fibers.

insulating concrete forms

Great insulation, resist hurricanes and tornadoes, easy insulation from a concrete point of view, faster construction, fire resistant

Sitecast concrete

Heavy type of construction, slow to construct, transport the concrete to site

Four major types of precast concrete slab elements

Hollow core tongue and groove channel double tee

Bell bottom piers

It is a single unit (monolithic) and has far greater strength and stability than a column of connected or unconnected concrete pushed piles.

Is movement in buildings normal?

Its not a bad thing if the building moves, they just move. Want them to have a little bit of give Soils settle overtime Within reason it is normal

Advantages to precast concrete

Most homogenous concrete - made in controlled environment Control of quality materials and workmanship Good surface quality Superior strength Erection is fast Can erected in a variety of climates Faster construction time (compared to sitecast)

Type 3 Slab on grade

Reinforced and transfer superstructure loads Can resist changes in soils Designed by a professional engineer ex: grade beams

Type 4 slab on grade

Reinforced and transfer superstructure loads Is not designed to resist changes in soils MUST be designed by a professional engineer Supported by piers or piles

glass fiber reinforced concrete (GFRC)

Same concept as fiberglass; however glass fiber is embedded in Portland cement and sand (concrete mixture) Used for ornamental structures, wall cladding, and soffits Precast The glass fibers reinforce the concrete, much as steel reinforcing bars do in conventional construction. The glass fiber reinforcement results in a product with much higher flexural strength than normal concrete, allowing its use in thin-wall casting applications.

what determines the foundation type

Subsurface soil and groundwater conditions Structural requirements, including foundation loads, building configurations and depth Construction methods Environmental factors Building Codes

Post tensioning

The concrete is cast with a hollow duct or sleeve to encase the steel. After the concrete has cured, the steel is tensioned and anchored into place.

good foundations satisfy three requirements

The foundation must be safe. This means foundation do NOT fail (crack or break). The soil/rock on which the foundation sits must not fail. The foundation must settle properly. If the soil collapses or moves too much, the foundation will fail. The foundation needs to be selected properly to avoid adverse effects to surrounding property.

Type 1 Slab on grade - Ideal soil conditions

Usually 4" thick Carries no superstructure loads No reinforced but may contain wire welded fabric Rectangular in shape Ex: driveway, sidewalks, pad work

Where are vulnerable areas on buildings

When a material makes a 90° turn it is a weak point, or when you have a lot of a certain material. Every 20 ft of masonry you put a joint so they can move without cracking

flat slab

When the loads or spans required are larger, the flat slab systems is used. With this system, the slab thickness is increased where the slab sits on the column. In addition, the a 'capitol' is added to the top of the column to increase strength. For the flat slab systems, spans are generally 30 feet.

Types of Portland cement; Type 2

a little bit stronger than type 1, still considered normal

crawlspace

a rectangle of concrete

what is a mock up

a sample. largely aesthetic, can be very expensive

Super structure

above ground portion

Anchor Bolt

added to concrete before it dries to tie concrete to frame of building

Type A

air entraining,

Auger Cast Piles

also known as continuous flight auger piles (CFA), are deep foundation elements that are cast-in-place, using a hollow stem auger with continuous flights. The auger is drilled into the soil and/or rock to design depth.

superplasticizers

also known as plasticizers or high-range water reducers (HRWR), reduce water content by 12 to 30 percent. Flowing concrete is a highly fluid but workable concrete that can be placed with little or no vibration or compaction. The effect of superplasticizers lasts only 30 to 60 minutes and is followed by a rapid loss in workability. Added to concrete at the jobsite.

Control joints

are joints that "score" the concrete controlling where the crack will occur in the concrete. Sometimes called a saw cut. Controlling a weak point in the material

Why arent basements common in texas

because of water in the soil. Top soil is made out of clay, which expands and contracts with water...

Deformation patterns

better grip by increasing surface area. Helping secure the connection between steel and concrete

formwork; vertical boards

cleats

Compression

concrete is strong in this type of stress

Romans

considered the inventors of concrete

Expansion Joints

create a physical space within the concrete. You have a space between the material and you have a joint sealing material.

drop in elevation on plan

crescent moon looking thing

Carton Forms

designed to hold up the weight of fresh concrete long enough for the concrete to cure and support itself on piers or beams. Since it is a paper product, it absorbs the moisture of the surrounding soil and concrete and its supportive strength gradually diminishes

Clear concrete

developed by Hungarian Architect Aron Losonczi. during the mixing process, glass fibers are added to the traditional stone,

Steel in specs sheet

division 3

What division is concrete

division 3

Shop drawings

drawings produced by fabricators, sub contractors; EX: cabinet maker. in the case of concrete engineer approves shop drawings

Precast concrete

eans the concrete is formed and cured in a factory, transported to the construction site and erected as rigid components.

deep foundations

either piles or caissons), penetrate through upper layers on unstable soil to transfer the load to the strong soil or rock deeper within the earth.

corrosion-inhibiting admixtures

fall into the specialty admixture category and are used to slow corrosion of reinforcing steel in concrete. Corrosion inhibitors can be used as a defensive strategy for concrete structures, such as marine facilities, highway bridges, and parking garages, that will be exposed to high concentrations of chloride.

Three principle two way slab concrete systems

flat plate, flat slab, waffle slab

wind loads

force produced by the wind. Wind can push a building sideways (lateral), downward (push on the roof) and upwards (pull on the roof)

Types of Portland cement; Type 3

high early strength; only put so much weight on the concrete as you go. Concrete takes around 28 days to cure, if you use a different mix you can start having the strength earlier.

accelerating admixtures

increase the rate of early strength development, reduce the time required for proper curing and protection, and speed up the start of finishing operations. Accelerating admixtures are especially useful for modifying the properties of concrete in cold weather.

ICF

insulating concrete forms

wall footing/ strip footing

is a continuous strip of concrete that supports foundation walls

Column footing

is a square block of concrete with or without steel reinforcing that accepts the concentrated load placed on it from above by a building column

Pre stressed concrete

is applying a force to the steel before the concrete is poured.

Shear

is both types of stresses

tilt up construction

is casting a wall panel in a horizontal position and then tilting it to it final vertical position. Usually, these panels are solid, reinforced slabs five to eight inches thick. They have to be able to attach to the crane

concrete joist system

is comprised of concrete members usually spaced 26 or 36 inches apart, running in one direction, that frame into larger beams.

reinforced concrete

is the term used when steel is embedded in concrete, it increases the tension strength of the concrete.

what happens when concrete cures

it gives of heat (heat of hydration) and forms chemical bonds

One way system

l of the columns, beams and slab are poured in place; reinforced concrete. The reinforced steel is tied together at the junction between the columns and beams

substructure

livable below ground portion (basement)

which of these loads is highly subjective

live load

Types of Portland cement; Type 4

low heat; when concrete cures it gives off heat. When you have a lot of concrete you want the concrete to release the heat at a slower heat.

Precast concrete systems

means the concrete is formed and cured in a factory, transported to the construction site and erected as rigid components

Cast in place or site cast

means the concrete is formed and poured on the construction site. The concrete mixture must be transported to the site or mixed at the site

Coefficient of Thermal Expansion

measure in terms of inches and degrees F. For every degree that changes in Fahrenheit they measure how much the material moves in inches

specs

more detailed than plans/drawings.. organized like a book, organized by the construction specifications institute (CSI)

Types of Portland cement; Type 1

normal typical concrete. sidewalks, driveways, foundations for wood structures

Bearing capacity

of your concrete is essential to make sure that what you plan to have supported by the wall or slab will not be too heavy and cause it to crack and break

Fly ash

often used as a pozzolan to produce hydraulic cement or hydraulic plaster and a replacement or partial replacement for Portland cement in concrete production. Pozzolans ensure the setting of concrete and plaster and provide concrete with more protection from wet conditions and chemical attack.

OCEW

on center each way

Cast in place concrete structural systems can be classified into two general types

one way and two way systems

Foundation

part of the building that transfers loads to the soil

What two things are included in construction documents

plans and specs

Slab on grade foundation

popular in texas, Use the ground to create your form, dig in ground. Create a system of trenches, line it with plastic, then you pour your concrete in mold. Structural engineer decides the distances and grades of rebar.

Waffle slab

provides support for heavier loads at slightly longer spans (up to 40 feet). Waffle slabs are formed of prefabricated, reusable metal or fiberglass forms..

foundations are either

shallow or deep

Precast concrete elements

slabs, beams, girders, columns, wall panels

Tension

steel is strong in this type of stress

Precast categories

structural architectural

Types of Portland cement; Type 5

sulfate; for environmental. Resist elements

flat plate

the slab is designed and reinforced to span in both directions. Typical span is 25' in both directions

Mat slab foundation

the soil is so terrible, instead of trying to excavate.. You make one super slab, excavate several feet into the ground with one super thick reinforced slab

why do most foundations fail

they are put on bad soil

Chair

used to keep rebar elevated from touching the ground/surface

water reducing admixtures

usually reduce the required water content for a concrete mixture by about 5 to 10 percent. The treated concrete can have a lower water-cement ratio. This usually indicates that a higher strength concrete can be produced without increasing the amount of cement

Formwork; Horizontal boards

wales

Cast in place structural elements include

walls, columns, beams

Too much water will

weaken the concrete

Live Load

weight of the people, furniture, and equipment used by people, snow, ice and water on roof

Dead Load

weight of the structural system, the floors, roof, walls, MEP

retarding admixtures

which slow the setting rate of concrete, are used to counteract the accelerating effect of hot weather on concrete setting. High temperatures often cause an increased rate of hardening which makes placing and finishing difficult. Retarders keep concrete workable during placement and delay the initial set of concrete


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