new 1 exam prep concrete finishing level 2 tabs and...

1 Exam Prep – Prov Concrete Finishing Level 2 1

1 Exam Prep

Concrete Finishing Level 2

Tabs and Highlights

These 1 Exam Prep Tabs are based on Concrete Finishing Level 2.

Each Tabs sheet has five rows of tabs. Start with the first tab at the first row at the top of the page; proceed

down that row placing the tabs at the locations listed below. Place each tab in your book setting it down one

notch until you get to the last tab (usually the index or glossary). Then start with the highlights.

Special Note to our Students: If you are a 1 Exam Prep student, here is how to really get the most from

these 1 Exam Prep Tabs. Follow the above instructions, but before placing the tab, find the tab's topic in the

outline of your appropriate module. Now locate and highlight several items listed in the outline just before

the topic, and just after. See how the topic fits in the outline and how it relates as a concept to the broader

concept spelled out in the outline. If you take a few minutes to do this, when you take the test key words in

the test questions will remind you of where the information is in the manual!

1 Exam Prep Tab Section

Properties of Concrete, Part Two 23201

Estimating Concrete Quantities 23202

Forming 23203

Site Concrete 23204

Architectural Finishes 23205

Industrial Floors 23206

Superflat Floors 23207

Surface Treatments 23208

Quality Control 23209

Guide for Concrete Floor and Appendix A

Slab Construction

Making Repairs 23210

Glossary

*This concludes the tabs for your book. Continue with the highlights for your book on the following page.


Section Highlight

Properties of Concrete, Part Two – Trainee Task Module (23201)

2.0.0 Specialty Admixtures: An admixture is defined by

the American …..during the mixing.

2.1.0 Use and Need For Admixtures: Admixtures affect the

properties of concrete by:

(11 Bullets)

2.2.0 Chemical Admixtures: Chemical admixtures can provide a

Variety of effects that help concrete finishers do their jobs

better. These include:

(5 Bullets)

2.2.1 Water Reducers: Typical water reducers drop the water

Content by 5 percent to 10 percent.

2.2.2 High Range Water Reducing Admixtures: High-range

Water reducers can reduce…..following different effects:

(3 Bullets)

Superplasticized concrete will have more bleeding and

…..water-cement ratio concrete.

2.2.3 Accelerators: Accelerators are added to concrete……

is calcium chloride (CaC12).

See Table 1. Effects of Calcium Chloride on Concrete Mix

Calcium chloride should be added to the mixing water……

94 percenter Ca1C12)

The 2 percent guidelines is a good number to remember

…….corrosion of reinforcement.

2.2.4 Retarding Admixtures: Retarding admixtures are used to slow

…….or the aggregate.

2.2.6 Air-Entraining Agents: Air-entraining agents are liquid

Chemicals added during mixing to produce microscopic air

bubbles in concrete.

To get the right bubble size and spacing, adequate air-entraining

………volume of the concrete.


Section Highlight Cont. from prior page: Entrained air also improves the

workability of concrete by increasing the volume of paste.

There are two ways to make air-entrained concrete…….

an air-entraining cement.

Too much air content causes a reduction in strength, but

…..minus 1 percent.

2.2.7 Other Types of Admixtures:

- Latex Admixtures

- Antifreeze Compounds

- Coloring Pigments

See Table 3. Coloring Admixtures

2.3.0 Mineral Admixtures: Finely divided mineral admixtures

are powdered or pulverized……portland cement concrete.

See Table 4. Specifications and Classes Of Finely Divided Mineral Admixtures: Finely divided mineral

Admixtures are often added…..of the aggregate.

2.3.1 Cementitious Materials: Cementitious materials include

some fly ashes……for portland cement.

- Found, Granulated Blast-Furnace Slag - Fly Ash

2.3.2 Pozzolans: Pozzolans usually improve workability. They are

also used…..yard of concrete.

- Natural Pozzolans - Fly Ash - Silica Fume

2.4.0 Fiber Reinforced Concrete: Fibers are used in concrete

flatwork to control crack propagation.

The addition of fiber reinforcement for other structural

……strength, and ductility.

2.4.2 Steel Fiber Reinforced Concrete: Steel fibers provide

modest increases….and impact forces.

2.4.3 Finishing Fiber Reinforced Concrete: Specific finishing

Procedures include the following:

(1st Bullet Only)


Section Highlight 3.0.0 Lightweight Concrete

3.1.0 Use of Lightweight Concrete: Lightweight concrete is used

primarily to lessen…..building, for example.

3.2.0 Type Of Lightweight Concrete: There are two general types

of lightweight concrete……for normal concrete.

3.2.1 Structural Concrete: Lightweight structural concrete is similar

………of lightweight concrete.

The unit weight of the fresh concrete is used to measure the

yield ……adjustment is required

3.2.2 Insulting Concrete: Low-density concrete, sometimes referred

…..120 pcf or less.

Low density concrete can be grouped as

follows:

(3 Bullets)

3.3.0 Finishing Lightweight Concrete: Since the course is generally

lighter……with lightweight concrete:

(3 Bullets)

4.0.0 Flowable Fill: Flowable fill is a mixture of fly ash, water,

portland cement and sometimes sand.

4.2.0 Properties of Flowable Fill: Flowable fill typically contains

Ash and water…..portion of the ash.

The two basic types of flowable fill mix are high fly ash

…….5 percent portland cement.

5.1.0 Blended Cements: Blended cements are produced by blending

………of these materials.

5.1.1 Uses for Blended Cements: Blended cements are used for the

……..in general construction.


Section Highlight 5.1.2 Properties Of Blended Cements: Some blended cements can

also…….are summarized below:

- Portland Blast-Furnace Slag Cement - Portland-Pozzolan Cement - Pozzolan-Modified Portland Cement - Slag Cement - Slag-Modified Portland Cement

5.2.0 High-Strength Concrete: High-strength concrete (HSC)

is generally…….high-strength concrete.

5.2.2 Properties of High-Strength Concrete: Cement content for

high-strength is normally……aggregate is ¾ inch.

5.5.0 Heavyweight Concrete

Estimating Concrete Quantities Module (23202)

2.1.0 Denominate Numbers: Denominate numbers have a unit

……..U.S. Customary Measure.

2.1.1 Denominate Addition

2.1.2 Denominate Subtraction

See Table 1. Common Measures

2.2.2 Converting SI Metric:

To convert from U.S. Customary to

SI metric, follow this procedure:

(3 Steps)

See Table 3. U.S. To Metric Conversions

Table 4 shows metric U.S. Conversions……

(3 steps)

See Table 4. Metric to U.S. Conversions


Section Highlight 2.3.1 Four-Sided Figures: The formula for finding the area…..

a = lw

a = a = bh

The formula for finding the area of a trapezioid……

a = [(A + C) x ½] x B

The formula for the area of a triangle is written as:

a = ½ bh or

2.3.3 Circles

2.3.5 Many Sided Irregular Figures

2.4.0 Solid Figures and Volumes: Area is calculated on two-

dimensional figures…..or cubic meters ( ).

Rectangular solid

Volume = length x width x height

V – lwh

Prism

Volume = (base x height, divided by 2) x height

V = [bh ÷ 2]h

Cylinder

Volume = x the radius squared x height V = ( )h

See Figure 11. Volumes of Special Solids

3.1.1 See Figure 12. Standard Plan Lines

(10 Bullets)

See Figure 13. General Plan Symbols

See Figure 14. Electrical and Plumbing Symbols

3.1.3 Scales and Dimensions: For residential drawings,

……………1 foot on the ground

Commonly, these detail scales are ½ inch to 1 foot

………….1 inch to 1 foot.


Section Highlight

See Figure 15. Sample Finish Schedules

3.2.0 Reading Residential Drawings: Working drawings are

Frequently…….the following order:

(3 Bullets)

For concrete craftworkers, the plot plan, the foundation

……………will be most important.

3.2.1 Plot or Site Plans: The plot or site plan shows the location

Of the building in relation to the property lines.

3.2.2 Foundation Plans: The footings are shown with dashed

(hidden) lines since they are below the slab.

3.2.3 Floor Plans: The floor plan is actually a cross-sectional view

Taken horizontally between the floor and the ceiling.

4.1.0 Calculating and Estimate: The first step in estimating, then, is

To find out what needs to be built.

4.1.2 Calculating Volumes: The formula to use is V = lwd

See Figure 17. Cubic Feet Calculations

4.1.3 Estimating the Concrete: Adding the total number of footing

at the bottom will help check that all the footings have been

included.

4.3.1 Column Footing or Box Footing: The formula for the volume

Of column footings or box footings is:

V = length x width x depth

V = lwd

4.3.2 Wall Footings: The volume of concrete in the footing would be

Calculated using the following formula:

V = [lwd] minus keyway [lwd]

4.3.5 Stairs: The concrete is placed stairs is figured at 1 cubic

foot of concrete for each linear foot of riser.

4.3.7 Columns: Round columns use this formula for volume:

V = (π d


Section Highlight

Forming Module 23203

1.1.1 Design Of Formwork: Responsibility for the design of ……….for the formwork.

2.1.0 Forming Materials: Forms are made of wood, metal, cardboard

…….of wood forms.

2.1.1 Wood For Forms: Wooden forms are by far the most common

type used in building construction.

See Figure 1. Typical Wood Form

Plywood is furnished in either interior or exterior type

…….comprise of three plies.

2.1.3 Fiberglass: The most common use is for the variously shaped

done pans that are used to form waffle floor systems.

2.1.6 Waste Molds: Complicated and ornamental surfaces can be

cast in plaster waste molds.

2.2.0 Types of Forms: Forms and forming systems usually fall

into one of three catagories:

(3 Bullets)

2.2.1 Job-Built Forms

2.2.2 Prefabricated Forms

2.2.3 Manufactured Forms

- Panelized forms

- Column forms

- Pan forms

2.2.4 Forming Standards and Practices: Plywood sheets less than

5/8 inch……..placed vertically.

See Figure 10. Placing Plywood Sheets On Studs

2.3.0 Treatments: Most forms must be treated with a form oil

……to the concrete.


Section Highlight 2.4.1 Fasteners: The most common fasteners for wooden form

……to the structure.

2.4.2 Ties

- Standard Tie Rod

- Form Clamp

- Snap Tie

- Coil Tie

- She-bolt

- Inserts

See Figure 12. Standard Tie Assembly

See Figure 13. Various Tie Assemblies

2.4.3 Form Clamps

2.5.0 Anchors

See Figure 16. Form Anchor Devices

2.7.0 Form Removal: After a form has been stripped, it should

……appropriate release agent.

2.8.0 Safety Concerns and Reshoring: Some of the common

construction deficiencies that may lead to form failure are:

(16 Bullets)

See Table 1. Conditions of variation From Plumb & Level

3.1.0 Establishing Line and Grade: At the beginning of excavating

a structure such as ………outside the excavation.

String line stretched between opposite batter boards define

both the line and grade……..setting line and grade.

In setting the form for a concrete wall……top is aligned.

3.2.1 Squaring Up Forms: The steps for squaring up the intersection

Of the two lines (or forms) are as follows:

(4 Steps)

See Figure 18. Creating A Right Angle Corner


Section Highlight 3.2.2 Using A Spirit Level: The spirit level is a level that can be

………follow these steps.

(6 Steps)

3.2.3 Setting Batter Boards And String Lines: Batter boards are

boards that are used to preserve the structure lines during

excavation and construction.

The stakes are driven into the ground beyond the corners of the

……..same place each time.

See Figure 22. Batter Board Setup

Because the batter boards are all the same…..

up the forms.

String lines can be used to provide alighment and grade

………..at the corners.

3.2.4 Leveling Instruments: The builder’s level is a simple

instrument…….have been established.

A level rod (like the one shown in Figure 26) is used with

the builder’s level …….and are colored black.

3.3.0 Using A Level To Set and Check Grades: If the elevation

of the forms…..top of it.

3.3.1 Checking Form Grade: Use the following steps to check

the elevation of the form at various points.

(10 Steps)

3.3.2 Setting Screeds: The steps necessary to carry out the activity

are given in the example layout shown in Figure 33.

(6 Steps - ** important info on step 6 **).

4.1.0 Large Slabs: The other method, called slipform paving, does

not require stationary forms for the placement of low slump

concrete.

Formwork for slabs on a grade less than 24 inches thick

……those for walls.

Slabs on grade can be constructed with or within any type of

foundation at their outer edge.


Section Highlight 4.1.1 Types of Forms: All wood edge forms are usually cut and

assembled……more boards together.

See Figure 37. Slab Edge Forms

Metal forms are used where added strength is required

……at another location.

4.1.2 Wood Forms for Slabs Without A Foundation: A 5’ slab

can be formed with 2” x 4” lumber…..2” thick formwork.

4.1.3 Wood Forms for Slabs with Foundations: Because the

sheathing…..the proper elevation.

4.2.0 Roadways and Parking Lots: Straight form sections that

deviate…..must be replaced.

4.2.2 Placing The Forms: Standard 10 foot straight forms are

accepting…………exceeding 100 feet.

4.2.3 Placing Embedded Objects: Cast-in-place utility fixture

and box out forms ………….of the slab.

5.1.0 Form Strength: The primary consideration in form design

…..workers, and equipment.

5.2.1 Construction Techniques: Fasteners should be concrete nails,

power-driven……of the sheathing.

See Figure 50. Sole Plate On Footing

Walers are attached horizontally to the outside…..

give the needed strength (See Figure 53).

Bracing for wall forms should be designed for a horizontal

……………..at the least 15 psf.

5.3.0 Prefabricated Wall Forms

5.3.1 Hand Set Forms: Panels for hand set forms are erected

…….sheathing is eliminated.

The steps for selecting the right size panels and accessories

are as follows:

(6 Steps)


Section Highlight 5.3.2 Ganged Forms

See Figure 57. Job-Built Wood Gang Form

5.4.0 Joints: In placing successive lift of concrete on previously

……the construction joint.

See Figure 59. Use Of A Grade Strip At A Horizontal

Construction Joint

Another method is to use a rustication groove to hide

……..to the form (shown in Figure 60).

See Figure 60. Placing A Rustication Groove

Form anchorages should be provided about 4 inches

below the………….of the new lift.

Site Concrete Module 23204

Section Highlight 2.0.0 Curb and Gutter: In general, curbs are grouped into two

general classes, barrier and mountable.

The barrier curb is a curb and gutter combination designed

to redirect an errant vehicle under most impact conditions.

The mountable curb is designed to allow vehicular traffic

to pass over.

See Figure 2. Types Of Curbs

Curb and gutters are used for storm water management

by directly the water to storm drain inlets located along

the alignment.

2.2.0 Establishing Grade and Subbase: All of the grade stakes

Must be set before beginning…….50 feet apart.

2.3.0 Forms: Concrete for this type of construction must have a

very low slump of ½ to 2 inches.

All forms should be straight, free from warping, and of

sufficient strength to resist concrete pressure without bulging.


Section Highlight 2.3.1 Laying Out and Setting Forms: The steps to this

procedure are as follows:

(13 Steps - * important info on Step 4*)

See Figure 8. Marking Elevation On A form Stake

2.4.0 Placing and Consolidating: Do not place concrete

In adverse weather conditions…..slump works well.

2.5.0 Finishing

2.6.0 Curing: The first step under any condition of exposure

……surface of the concrete.

2.7.0 Removing Forms: In summer, concreting forms should

be removed as soon as practical, with specified curing

started immediately.

As you strip the forms, clean them with a scraper and wire

brush.

3.1.0 Layout: Stairs for residences are usually 48 inches wide. The

layout of any stairs must begin with determining the rise and run

that must be covered by the stairs.

The general rule of thumb is that the sum of the riser and

Tread should be equal to 18 inches.

See Figure 16. Example Stair Calculation

3.2.1 Subgrade Preparation: For outside stair construction,

a footing is constructed for the stairs to rest on.

In general footings for stairs should be placed at least 2’

deep in firm……..6 inches thick.

3.2.2 Formwork

Figure 19. Earth Supported Stairs Between Walls If stairs are more than 4 feet wide, it will be necessary

to add a center stringer or center brace for temporary

support.


Section Highlight

Figure 21. Bevel on Bottom Of Riser Form On wide stairs, riser supports and braces should be

……………..of the stairs.

Riser should be checked with a hand level and positioned

…….back to the front.

3.2.4 Finishing: In one method, stripping of reiser forms begins

………..the concrete sets.

In the other method, treads and landings are finished soon

…………patching is done.

See Figure 23. Types Of Nosing: The other way to finish risers

and sidewalls involes the……..and stone rubbing.

3.3.2 Placing And Finishing

(10 Steps - * important info on step 1)

4.1.1 Planning The Work: The plot plan (like the example shown

in Figure 27)……..to be built.

See Figure 27. Plot Plan

Large-scale detail sheets show more detail about a

………………..a residential street.

See Figure 28. Detail Drawing Depending on the type of work, inspections of the

work at critical steps with be required.

4.1.2 Staking: Some form of guide must be used to show where

……..and string lines.

You can easily check the formwork for square by using the

……..measure 5 feet.

One way to set up corners is to use a batter board, as shown

…………is level and true.

With all four level string lines in place, double-check

………...are not square.

See Figure 90. Stakes With String Line


Section Highlight 4.2.1 Preparing The Subgrade: If there are utility trenches that

…………..4 inch thick.

4.2.2 Reinforcement Requirements: Reinforcing bar used in

……….3/4 inch in diameter.

4.3.2 Setting Forms: Some general points to remember when

setting on grade forms are as follows:

(4 Bullets)

For good drainage, forms should be built to slop the slab

¼ inch per foot in length, in width or in both directions.

4.4.0 Placing: Moving the concrete horizontally on the ground

…………..in the mix.

The remainder of the placing technique is the standard

procedure used for typical slab. A summary of these steps

follows.

(3 Steps)

4.5.0 Joint Placement

4.5.1 Contraction Joints: Contraction joints (sometimes call control

joints)………slump concrete is used.

4.5.2 Isolation Joints: An isolation joint is formed by inserting a

joint…………it works well.

4.5.3 Construction Joints: Whenever work stops for the day or for

………..doweled joints are preferred.

4.6.0 Finishing: Begin the finishing of the slab when the water sheen

………….so of indentation.

4.6.1 Troweling: Troweling is not recommended for exterior slabs

……..entrainment at the surface.

Never trowel a surface that has not been floated by hand or

……….surface for troweling.

4.7.0 Curing: Proper curing greatly increases the strength and

durability of concrete.

Keeping concrete sufficiently moist for proper curing is done

………..covering is burlap.


Section Highlight 4.8.0 Form Removal: After the concrete has cured for one day,

carefully remove the forms.

6.1.0 Laying Out and Staking: Grading lines, where used,

should be ………and horizontal curves.

Architectural Finishes Module 23205

2.1.0 Surface Classes

- Class A Surface

- Class B

- Class C

- Class D

3.0.0 Coloring Concrete: Tinted or pigmented concrete is also

……other finishing coats.

3.1.0 White Cement: White cement can be used as structural

………..chance of bugholes.

3.2.1 Natural-Colored Cements: Natural-colored cement are

standard portland cements with a tint of light gray or light tan.

3.2.2 Pigmented Cement

See Table 1. Common Cement Coloring Agents

3.3.0 Placing Tips: The following recommended procedures

will help keep the mix color uniform during the placing

and finishing.

(14 Bullets)

3.4.1 Color Stains: The stains are usually a suspension of metallic

salts in muriatic or other acid solutions.

3.4.2 Dry Shake Color Hardeners: Color shakes give a more intense

color than integral color because they concentrate the color

at the surface.

4.1.0 Selecting Aggregates


Section Highlight

See Table 2. Aggregate Colors

Typical sizes ranges from 3/8 to ¾ inch. Aggregate less than

3/8 inch may wash out during the finishing process.

Avoid using flat or ball-shaped particles because they do not

bond properly and are easy to dislodge from the mortar.

4.2.0 Other Ingredients

Gap-graded concrete is often used for exposed-aggregate

surfaces. This is concrete with no intermediate-sized aggregate.

4.3.1 Integral Method: The integral method is used for both

…….at the surface.

The concrete for the integral method must have a slump

………….be 1 inch or smaller.

4.3.2 Topping or Seeding Method: Topping or seeding freshly

……..for the top course.

The base course should have a slump of 2 to 4 inches. If it is

……….are shown in Table 3.

See Table 3. Strikeoff Allowance By Aggregate Size

The aggregate should be clean and moist to prevent drawing

water form the concrete.

4.3.3 Sand Bedding Method: Sand bedding is used for vertical

panels that are cast horizontally.

Place the aggregate in a uniform layer over the sand, covering

….......settle the sand.

4.4.1 Water Washing and Brushing: Water washing and brushing is

………..surface hardened completely.

4.4.2 Grinding and Polishing: The grinding and polishing technique

works on both horizontal………can be ground.

5.2.0 Waterblasting: Waterblasting equipment used for exposing

aggregate consists of a high-pressure water jet tool with

injector tip.


Section Highlight When the concrete reaches the strength of about 1500 psi

remove the forms and begin waterblasting immediately.

Hold the nozzle 6 to 10 inches away from the surface.

6.2.0 Travertine or Keystone: The travertine or keystone treatment

……….break up the suface.

The ridges should be about ¼ to ½ inch high.

7.1.0 Forms and Form Liners: The forms are usually made of wood,

aluminum, or other metal and give a low relief texture of about

¼ inch deep or less.

Industrial Floors Module 23206

2.0.0 Floor Classes

See Table 1. Floor Classifications

2.1.0 Industrial Floors: As listed in Table 1, each of the five

……….and suggested finish.

A Class 7 floor is made of two courses bonded together

with a metallic or mineral aggregate suggested for the top

course.

2.3.0 Tolerances: Contract specifications will vary according to use

……of 25 or greater.

3.1.0 Slab Support: A durable industrial flow must begin with a

………leveled to grade.

The rough grading of the subgrade for an industrial floor

………..1 ½ inches.

Sometimes, a thin layer of fine-graded granular material

………..and the slab.

See Figure 3. Underpinnings of Slab On Grade

The subgrade should give uniform support to each layer

………..from the completed floor.


Section Highlight 3.2.0 Moisture Control: Wet areas may require special drains,

……….slab is place.

See Figure 4. Exterior Perimeter Drain

Sometimes interior drainage is also necessary for industrial

………the slab surface.

3.3.0 Forms And Screeds: These forms can be made of metal or

lumber set on edge with stakes every 4 feet and at all joints.

Another type of intermediate screed is the wet screed. This

is a strip of concrete……….between grade stakes.

3.4.0 Embedments: Industrial floors usually have embedments such

as anchors and drain fittings. As a general rule, any pipe

…………of concrete below.

3.5.0 Reinforcement: Rebar wire, mesh and tensioning cables must

………the specified cover.

3.5.1 Steel Bar Reinforcement: It comes in a smooth or a deformed

…………….in the United States.

See Figure 6. Rebar Markings

Bar sizes are measured in eights of an inch. The size number

………1 1/8 inches in diameter.

Splicing can be done by welding, using a mechanical splice

………whichever is larger.

See Table 3. UBC Reinforcement Cover Tolerances

3.5.2 Wire Mesh: The heaviest grade is called bar mat, and is

typically used in payment construction.

3.5.3 Post-Tensioned Tendons: Post-tensioned (PT) cabling

reinforces concrete by means of high-strength steel

…………eliminate shrinkage cracking.

3.6.0 Joints: Most industrial floors are designed to minimize the

…….footings, and drains.

See Figure 11. Isolation Joints


Section Highlight

See Figure 12. Doweled Construction Joint

See Figure 13. Doweled Contraction Joint

Filling joints reduces the chances of spalling from

abrasion at the lip of the joint.

4.0.0 Placing Floors: The general procedure for placing

is as follows:

(5 Bullets)

5.1.0 General Procedures: Industrial floors share the process

of corrective ……….the surface less flat.

See Table 4. Typical Forming, Strike Off, And

Finishing Requirements (1 of 2) and (2 of 2)

6.1.0 Types of Shakes: Crushed trap rock, quartz, emery,

corumdum and granite……….3/8 inch in diameter.

6.2.0 Applying Dry Shakes: The following application procedure

are recommended for dry shakes, nonslip shakes, and color

shakes.

(7 Steps)

7.0.0 Curing: The curing process must begin as soon as finishing

………synthetic fiber mat.

Superflat Floors Module 23207

1.1.0 Introduction: According to the American Concrete Institute (ACI) classification …………direction of travel.

2.1.0 Superflat Floor Tolerances: The F-number system used floor

……..measure of levelness.

If a floor is perfectly flat over a 24-inch distance, even though

it may not be level, the curvature value is zero.

2.1.1 Overall and Local Values: When using the F-number system

……….Minimum Local Value (MLV).

2.1.2 Minimum Values: Specifications for superflat defined-traffic

…………area was designed.


Section Highlight

2.2.0 Measuring Instruments: The dipstick measuring instrument

……..random-traffice floors.

See Figure 3. Dipstick Instrument

2.3.0 Factors Influencing F-Number Values: Levelness values

) are influenced by the craftworker’s accuracy in setting forms on grade.

Flatness values ( ) are influenced by the finishing operations after strikeoff.

3.1.0 Subgrade Support

The rough grading of the subgrade should conform

to a tolerance of plus 0 inches and minus 1 ½ inches.

Post-tensioned superflat floors can require an additional layer

……..topping slab.

3.2.0 Forms: Superflat floors are typically constructed in strips or

lanes that are 20 feet wide or less.

Edge forms for slabs must be set accurately to line and grade

………….speed form stripping.

To check whether the top of a form is flat, place a 10-foot

…………shown in Figure 10.

3.3.0 Joints: Any contraction joint in a superflat floor should

be saw-cut and filled with semirigid epoxy as shown

in Figure 11.

See Figure 11. Saw-Cut Joint Schematic

3.4.0 Mix Design

Two basic requirements of all mixes used for superflat

floors includes:

(2 Bullets)

4.0.0 Placing: The most important consideration is consistency and

continuity in the concrete supply.


Section Highlight Therefore, a continuous supply of concrete with the same

properties is important.

4.1.0 Long-Strip Placing

ACI recommends successive long string placement for

………the existing slab.

4.2.0 Wide-Strip Placing

The laser screed can handle placements from 88 to 112

feet wide without the need of intermediate forms.

5.1.0 Hand Finishing: When hand finishing superflat floors,

the tool used most often is the 10 – or 12 foot highway

straightedge.

The straightedging is done in two subsequent or simultaneous

……….to the first place.

Hand finishing with trowel is important around the edges of

the forms.

5.2.0 Machine Finishing: Float pans can be used on any

nonoverlapping ride-on………with the concrete.

5.3.2 Measuring: The process of measuring for flatness and levelness

………………reading are taken.

6.0.0 Curing: The curing process must begin as soon as finishing is

………foot traffic earlier.

They are often used as curing agents on industrial floors because

most of them will permit foot traffic after two days.

Application should be in a crossing pattern to make sure of

coverage.

There are several types of membrane-forming compounds that

………..are as follows:

(3 Bullets)


Section Highlight

Surface Treatments Module 23208

1.0.0 Introduction - Monolithic Toppings - Separate Bonded Toppings - Unbonded Toppings - Partially Bonded Toppings

2.1.0 Safety

When working with any chemical preparation compound,

it is important to follow these rules:

(4 Bullets)

When working in a situation with airbourne contaminats,

it is important to follow these rules:

(4 Bullets)

2.2.0 Surface Profile

The Concrete Surface Profiles (CSP) are shown in Figure 1.

…………….and contract documents.

See Figure 1. Concrete Surface Profile

Measures of Roughness

2.3.2 Low-Pressure Water Cleaning: In low-pressure water

cleaning, water is………water-soluble contaminants.

2.3.4 Grinding

It is not recommended for removing soft coatings

…………and methacrylate coatings.

2.3.5 Abrasive (Sand) Blasting: Abrasive sandblasting prepares

surface for applying sealers, coatings and polymer overlays.

2.3.6 Shotblasting: The shotblasting process can remove dirt,

laitance……………………..of surface preparations.

Usually, a single pass will remove a depth of up to

………..tar-based materials.


Section Highlight 2.3.8 High Pressure Water Jetting: High and ultra-high pressure

water jetting………..removing sound concrete.

3.0.0 Dry Shakes: Dry shakes are applied to concrete to:

(5 Bullets)

Dry shakes are also known as monolithic toppings.

3.1.3 Nonslip (Abrasive) Shakes: The two most commonly used

nonslip materials are silicon carbide and aluminum oxide.

3.2.0 Applying Dry Shakes

The following general procedure is recommended for applying

dry shakes.

(7 Steps)

4.0.0 Self-Leveling Toppings and Underlayments: Self-leveling

toppings provide a smooth …….for tile or carpet.

4.1.0 Moisture and Bonding

A calcium chloride cup test can be performed to measure

the moisture emission rate of the slab.

Another test (ASTM D4263) calls for taping a 18 inch

……….for topping layer.

4.2.0 Applying a Self-Leveling Topping: The minium and maximum

thickness of a topping depends……..4 inches thick.

The procedure for applying a self leveling bonded topping is as

follows:

(7 Steps)

5.0.0 Protective Sealers and Coatings

Proper surface preparation is the single most important step

……..must be removed.

5.1.0 Sealers: Sealers range in thickness from 0 to 3 mils

……………………urethanes, and acrylics.


Section Highlight 5.2.0 Thin Film Coatings: Thin film coatings range from 4 to 10

in thickness when dry.

Acrylic-latex combinations and some polyurethans are

forumulated ………..in the surface.

5.3.0 High-Build Coatings: High-build coatings range in thickness

from 10 miles to ½ inch when dry.

Quality Control Module 23209

1.1.0 Introduction

On most construction jobs, the standard of quality is set

……………(AASHTO).

1.2.0 Quality Control: Quality control is usually defined in specifications as…….in the contract.

3.2.0 Sampling Fresh Concrete

The procedures for sampling concrete according to ASTM C172

are summarized as follows:

(1st Bullet Only)

3.3.0 Making Test Specimens

Cylinder-shaped specimens are used for testing compressive

……..form removal time.

Test specimens are usually made in set of 2 or 4 for

strength testing at 7 and 28 days.

3.4.0 Curing and Transporting Specimens: After the initial 24

hours the test specimens ……..on the site.

Specimens are cured in the laboratory when they will be used

………sand or sawdust.


Section Highlight 3.5.0 Test and Acceptance Criteria

The concrete strength is considered acceptable as long as:

(2 Bullets)

One strength test result is the average of the strengths

…….in the specifications.

4.1.0 Slump Test: The slump test (ASTM C143) measures the

workability and consistency of a batch of concrete.

See Table 3. Slump Acceptance Tolerances

4.2.0 Air Content Test: Typical concrete usually has less than

5 percent………..in the air content.

4.2.2 Test Procedure



(Step 1 Only)

5.1.0 Formwork: The first step in inspecting formwork is to

…….the correct location.

5.2.0 Reinforcement

One of the first items are the markings on the reinforcing

………..for the job.

Quality control technicians should also check that reinforcement

……..minimum concrete cover.

5.3.0 Subgrades and Footings: Subgrades, bass, and footings should

be inspected before any formwork is placed.

6.1.0 Flatness and Levelness

(Step 2 Only)

See Figure 11. Flatness/Levelness Use Guide


Section Highlight 6.1.2 Setting and Achieving Tolerances

The most critical factors in achieving flatness and levelness

are the placing and finishing techniques used.

7.1.1 Hot Weather: ACI 305, Hot Weather Concreting, defines

hot weather……..in abnormal properties.

7.1.2 Cold Weather: ACI 306, Cold Weather Concreting, defines

cold weather……..below 40 F.

Making Repairs Module 23210

1.1.0 Introduction

Good craftwork during placing and finishing is the best

way to prevent problems; however, not all problems can be

prevented all the time.

2.1.0 Identifying Defects: Cavitation is a serious problem in dams

…….other suspended slabs.

Structural and environmental problems need to be remedied or

averted in some way before repairs are made.

See Table 2. Construction Technique Defects

See Table 3. Common Causes and Common Defects

in Concrete Slabs

2.2.2 Materials Performance

The repair material must be compatible with the existing

…………..the repair material.

See Table 4. Structural Properties For Service Conditions

See Table 8. Characteristics Of Selected Repair Materials

(Both 1 of 2 and 2 of 2)

See Table 9. Repair Techniques and Materials

(Both 1 of 2 and 2 of 2)


Section Highlight 2.3.1 Cracks and Spalls: The most common defects to be repaired

and cracks and spalls.

2.3.3 Delaminations: Deterioration occurs inside the slab before

the surface ………..of the reinforcement.

2.4.1 Unreinforced Concrete Surfaces

The first step in any repair is to remove the damaged concrete.

2.4.2 Reinforced Concrete: The most frequent cause of damage

to reinforced steel is corrosion, followed by chemical attack.

3.1.0 Small Areas: The following procedures can be used to patch

small to medium-sized areas.

(8 Steps - ** Step 1 is important **)

3.2.0 Large Areas

4.0.0 Grinding and Milling: Some minor defects such as low spots

and surface cracks can be repaired by grinding or milling.

Current safety regulations are explicit for using dry grinders or

milling machines. Craftworkers must wear appropriate personal

protective equipment, including:

(3 Bullets)

5.1.0 Thin Bonded Overlay: Surface preparation is vital for

bonded overlay.

5.1.1 Concrete Topping

5.2.0 Unbonded Toppings: The following procedure is

recommended for applying an unbounded topping:

(6 Steps – ** Step 5 is important **)

6.0.0 Lost Edge Repair

8.0.0 Joint Maintenance and Repair: When repairing joints, these

point are helpful to remember:

(2 Bullets Only)

new 1 exam prep concrete finishing level 2 tabs and...

Documents