JAB Plastic Products Corp.

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JAB Plastic

Products Corp.


Technical Information

WHAT DO CURRENT DESIGN CODES,
STANDARDS AND MANUALS OF PRACTICE
REQUIRE?

UNIFORM BUILDING CODE (UBC)




1997 UBC, VOLUME 2


STRUCTURAL


ENGINEERING DESIGN PROVISIONS



Chapter 19, Section 1907.5


Placing


Reinforcement




Chapter 19, Section 1907.6


Spacing


Limits for Reinforcement




Chapter 19, Section 1907.7


Concrete


Protection for reinforcement




Same requirements as for the International


Building Code (IBC)


INTERNATIONAL BUILDING CODE (IBC)




Section 1907.5.1


Bar Support:


Reinforcement bar shall be accurately


placed and adequately supported before


concrete is placed, and shall be secured


against displacement within tolerances.




Section 1907.5.2


Tolerances:


For Slab depth, d


8 inches;



d,
±

3/8 inch



concrete cover,


3/8 inch


For Slab depth, d > 8 inches;



d,
±

1/2 inch



concrete cover,
-

1/2 inch


Tolerance for Cover shall not exceed


minus 1/3 the minimum concrete cover


required by the approved plans or


specifications.

IBC REQUIREMENTS, CONT.



Section 1907.6




Minimum space between bars in slab must


comply with ACI 318, Section 7.6.


S
min.

horizontally or vertically = One Bar


Diameter or 1 inch




Section 1907.7.1



Minimum concrete cover for non pre
-
stressed


cast in place concrete:


Concrete permanently expose and cast


against soil


3”


Concrete expose to soil or weather:



For #6 through #18 Bar


2”



For #5 & W31 or D31 or



smaller


1½”

IBC REQUIREMENTS, CONT.




Concrete not expose to weather or in


contact with soil:



For slab
-

#11 bar or




smaller
-

¾ inch



Standard Specification, Division I


Design,


Section 8.21 provides a minimum distance


between reinforcement bars:

AMERICAN ASOCIATION OF STATE
HIGHWAY AND TRANSPORTATION
OFFICIALS (AASHTO)



For bridges’ cast in place concrete slab:




S
min.
= 1½ Bar Diameter or




1½ Max. Diameter of




Coarse Aggregate or




1½ inches




Standard Specification, Division I


Design,


Section 8.22, Minimum concrete covers:



Concrete expose to soil or weather:



Primary reinforcement


2”



Stirrup, tie
-
up, spiral
-

1½”


AMERICAN ASOCIATION OF STATE
HIGHWAY AND TRANSPORTATION
OFFICIALS (AASHTO), CONT.




Standard Specification, Division I


Design,


Section 8.22, Minimum concrete covers:



Concrete slabs exposed to mild climates:



Negative reinforcement


2”



Positive reinforcement
-

1”




Concrete slabs without positive corrosion


protection and frequently exposed to


deicing salts:



Negative reinforcement


2½”



Positive reinforcement
-

1”


AMERICAN ASOCIATION OF STATE
HIGHWAY AND TRANSPORTATION
OFFICIALS (AASHTO), CONT.




Standard Specification, Division I


Design,


Section 8.22, Minimum concrete covers:




Concrete slab not expose to weather or


in contact with soil:



Primary reinforcement


1½”



Stirrup, tie
-
up, spiral
-

1”




Standard Specification, Division II


Const.,


Section 9.6, Placing and tie
-
up of reinforcement


bars


requires:




Tie
-
up all reinforcement bar intersection


around the perimeter of the steel mat.

AMERICAN ASOCIATION OF STATE
HIGHWAY AND TRANSPORTATION
OFFICIALS (AASHTO), CONT.



Tie
-
up every two (2) feet maximum


center to center or at any other


intersection, the greater of the two,


for the rest of the bar intersections.



Section 9.6.2


“reinforcement bar could


be supported on any approved


mechanism.



Use sufficient supports to maintain the


steel bar in position in order to keep


the distance between bars and forms or


the slab surface within tolerance
-

¼ inch


of specified on plans or specifications.


The weight of workers and equipments


must be supported against the forms not


against the reinforcement bars.

AMERICAN ASOCIATION OF STATE
HIGHWAY AND TRANSPORTATION
OFFICIALS (AASHTO), CONT.





CONSTRUCTION INSPECTION MANUAL


FOR REINFORCED CONCRETE STRUCTURES


BY THE AMERICAN CONCRETE INSTITUTE


(ACI SP
-
2 (99))




STANDARD PRACTICES FOR REINFORCING


STEEL DETAILING BY THE CONCRETE


REINFORCING STEEL INSTITUTE (CRSI)

MANUALS OF STANDARD PRACTICES IN

THE CONSTRUCTION INDUSTRY




Steel rebar shall be firmly supported in place.



Reinforcement supports shall be of adequate


capacity and sufficient chairs be placed at the


right locations to support the reinforcement


steel and the construction loads at which it will


be subject to prevent the sagging of the steel


and reducing the distance between the steel


and the forms or earth base.



Allows the use of plastic chairs among other


materials. Do not use rocks, wood blocks or


other materials not approved for rebar support.

MANUALS OF STANDARD PRACTICES IN

THE CONSTRUCTION INDUSTRY





In general, support horizontal bars at every


5 or 6 feet.



Tie
-
up intersected steel bar at a maximum


of 2 or 3 feet or every other intersection.



To prevent corrosion and to avoid any


surface stains use plastic chairs or


stainless steel chairs.

MANUALS OF STANDARD PRACTICES IN

THE CONSTRUCTION INDUSTRY


STANDARD TESTS PERFORMED ON

JAB SNAP
-
ON & SUPPORT SYSTEM.

TEST #1 (COMPRESSION)

Figure 3


Arrangement Used during the Compression Test

-50
0
50
100
150
200
250
300
350
400
450
500
550
600
650
700
750
0.00
0.02
0.04
0.06
0.08
0.10
0.12
0.14
0.16
0.18
0.20
0.22
0.24
Load (Lbs)

Displacement (in)

PLASTIC CHAIR FOR 1.5" CONCRETE COVER



Test # 2 Pmax = 486 Lbs
-

Type 2 Failure

Test # 5 Pmax = 687 Lbs
-

Type 1 Failure

Test #4 Pmax = 439 Lbs
-

Type 2 Failure

Test #3 Pmax = 550 Lbs
-

Type 2 Failure

Test #1 Pmax = 440 Lbs
-

Type 2 Failure

Load vs. Displacement Curve for 1.5" Chair and # 3 Rebar

0
50
100
150
200
250
300
350
400
450
500
550
600
0.00
0.02
0.04
0.06
0.08
0.10
0.12
0.14
0.16
0.18
0.20
0.22
0.24
Load (Lbs)

Displacement (in)

PLASTIC CHAIR FOR 1.5" CONCRETE COVER



Test # 2 Pmax = 419 Lbs
-

Type 2 Failure

Test # 1 Pmax = 353 Lbs
-

Type 2 Failure

Test # 3 Pmax = 523 Lbs
-

Type 1 Failure

Test # 4 Pmax = 565 Lbs
-

Type 1 Failure

T
est # 5 Pmax = 516 Lbs
-

Type 1 Failure

Load vs. Displacement Curve for 1.5" Chair and # 4 Rebar

STANDARD TESTS PERFORMED ON

JAB SNAP
-
ON & SUPPORT SYSTEM.

TEST #2 (SEGREGATION)

Core Sample
-

Chair 1.5”

Core Sample
-

Chair 2.5”

Core Samples

STANDARD TESTS PERFORMED ON

JAB SNAP
-
ON & SUPPORT SYSTEM.

TEST #3 (SLAB BENDING)

For

the

test,

three

(
3
)

reinforced

concrete

slabs

with

measurements

of

ten

(
10
)

feet

long,

four

(
4
)

feet

wide

and

four

(
4
)

inches

thick

were

built
.

The

objective

of

the

test

was

to

locate

the

chairs

within

the

slabs

in

similar

conditions

to

which

they

will

be

subjected

in

everyday

use,

and

load

test

the

slabs

to

determine

if

the

use

of

the

JAB

plastic

chairs

results

in

localized

cracks

or

fissures

around

the

chairs

or

the

development

of

any

unexpected

crack

patterns

along

the

width

of

the

slab
.

The

three

(
3
)

specimens

built

for

testing

differ

from

each

other

in

the

amount

of

steel

or

steel

ratio

used
.

For

slab

number

1
,

four

(
4
)

-

#
3

rebar

were

used
.

For

the

slab

number

2
,

five

(
5
)

-

#
3

rebar

were

used
.

For

slab

number

3
,

seven

(
7
)

-

#
3

rebar

were

used
.

Based

on

these

parameters,

slab

#
1

should

support

under

service

load

conditions,

20

pounds/ft
2

of

live

load

in

addition

to

its

own

weight,

slab

#
2

-

30

pounds/ft
2

of

live

load

and

the

slab

#
3

-

40

pound/ft
2

of

live

load
.


SLAB BENDING TEST

Figure 9


General View of Slab forms, chairs and rebar before
pouring concrete

Figure 9 illustrates a general view of the specimens showing
the location of the plastic chairs and the steel before pouring
the concrete. The concrete used for these tests was pre
-
mixed.
The maximum size of the coarse aggregate was ¾” nominal
diameter. The average of six (6) cylinders, concrete
compressive strength (f’c) was 2,310 psi at 28 days. This f’c
was inferior to those normally specified in common
construction for structural members (e.g. 3,000 psi).







Figure 10


Block load application sequence used during the
testing

Figure 10 shows markings drawn to identify the sequence
and the location of the blocks upon the slab. It was
designed to simulate a uniform distributed load after all
concrete blocks were in placed.


Figure 11
-

General View of the Load applied to Slab 1

Figure 12


Crack Pattern on the Central Zone of Slab 3

Figure

11

shows

one

of

the

reinforced

concrete

slabs

during

the

loading

procedure
.

Before

starting

the

test,

various

blocks

of

6


x

8


x

16


were

weighed

and

an

average

weight

was

calculated

to

compute

the

number

of

blocks

needed

for

each

specimen
.

With

an

average

weight

of

30

pounds,

27

blocks

were

located

over

slab

#
1
,

40

blocks

were

located

over

slab

#
2

and

54

blocks

were

located

over

slab

#
3

to

simulate

the

corresponding

live

loads

of

approximately

20

pounds/ft^
2
,

30

pounds/ft^
2

and

40

pounds/ft^
2
,

respectively
.

Figure

12

illustrates

the

cracks

pattern

observed

during

the

tests
.

On

each

of

the

slabs,

cracks

begin

to

appear

after

20

blocks

have

been

placed

on

the

slab
.

The

cracks

appear

on

or

near

the

center

and

extended

all

over

the

width

of

slab
.

No

crack

concentrations

were

found

around

the

chairs

or

along

the

slab

where

the

chairs

were

located
.

No

crack

patterns

different

from

what

normally

can

be

found

in

reinforced

concrete

slab

with

steel

wire

or

cement

mortar

(“limbers”)

rebar

supports

subject

to

bending

were

observed
.

The

difference

found

between

each

one

of

the

specimens

was

not

in

the

crack

pattern

but

in

the

amount

of

cracks

found

along

the

width

of

the

slab

and

the

measurement

(width)

of

the

crack
.

The

difference

was

expected

since

the

load

applied

was

doubled

from

slab

#
1

to

slab

#
3
.

STANDARD TESTS PERFORMED ON

JAB SNAP
-
ON & SUPPORT SYSTEM.

TEST #4 (FILTRATION)

Figure 13


Arrangement Used during the Filtration Tests

Figure 14


Bottom View of Concrete Slab alter 10 days

With

the

objective

of

evaluating

if

placing

the

JAB

plastic

chairs

instead

of

the

metallic

or

mortar

supports

could

contribute

to

develop

a

localized

filtration

condition

in

the

slab,

a

test

was

specifically

designed

to

evaluate

the

effect

of

the

plastic

chairs

in

the

filtration

pattern
.

The

test

consisted

in

maintaining

1
.
5

inches

of

water

on

the

surface

of

slab

for

ten

(
10
)

days
.

During

this

period

of

time,

the

filtration

pattern

was

visually

observed,

evaluating

specifically

if

the

water

filtration

was

somehow

increased

or

different

around

the

zones

where

the

plastic

chairs

were

located
.

Figure

13

shows

the

arrangement

used

for

the

tests
.

Figure

14

shows

that

after

10

days

of

maintaining

the

top

portion

of

the

slab

submerge

in

water,

no

filtration

marks

were

noticed

around

the

location

of

the

chairs

nor

along

any

of

the

cracks

under

the

slab
.

The

daily

observation

made

under

the

slab

during

the

preceding

9

days

concurs

with

the

final

observation

at

day

10

of

the

test
.


Slab

Filtration

Test

JAB SNAP
-
ON & SUPPORT SYSTEM


INSTALLATION PROCEDURES


REBAR QUANTITY AND INSTALLATION PATTERNS
SHOULD BE AS INDICATED BY THE JAB PLASTIC CHAIR
QUANTITY CALCULATOR, BUT FOR THE MOST PART
THE FOLLOWING RESTRICTIONS APPLY:


TO AVOID SAGGING OF THE REBAR, LOCATE CHAIRS AT A
DISTANCE NOT GREATER THAN:


FOR #3 OR 3/8” BARS
-

2 FEET CENTER TO CENTER


FOR #4 OR ½” BARS
-

3 FEET CENTER TO CENTER


FOR #5 OR 5/8” BARS
-

4 FEET CENTER TO CENTER


FOR BIGGER BAR NUMBERS, CHAIRS SHALL IN NO EVENT BE
LOCATED FARTHER APART THAN 5 OR 6 FEET CENTER TO CENTER


TO ELLIMINATE THE USE OF TIE
-
UP WIRES, LOCATE PLASTIC
CHAIRS AT A DISTANCE OF 2 FEET OR LESS CENTER TO CENTER IN
BOTH DIRECTIONS

JAB SNAP
-
ON & SUPPORT SYSTEM
INSTALLATION PROCEDURES,

CONT.


ALWAYS VERIFY THAT REBARS ARE LOCATED AT
THE RIGHT POCKET FOR PROPER GRIP. THE GRIP
PROVIDED BY THE SNAP
-
ON FEATURE OF THE CHAIR
IS STRONG ENOUGH TO KEEP REBAR IN PLACE,
THEREFORE EXCEEDING CODE REQUIREMENTS.


ALWAYS VERIFY THE REQUIREMENTS OF THE CRSI
STANDARD PRACTICE OR STEEL DETAILING
MANUALS FOR PROPER LOCATION OF THE CHAIRS


THERE ARE SPECIFIC AND DIFFERENT REQUIREMENTS
FOR EACH TYPE OF STRUCTURAL SLABS AND SLAB ON
GRADE

PRODUCTS AVAILABLE FOR DELIVERY NOW!

HEAVY DUTY 1.5” INCHES HIGH

FOR #2, #3 & #4 REBARS

& 6x6
-
10x10 WIRE MESH

HEAVY DUTY 2.5” INCHES HIGH

FOR #3, #4 & #5 REBARS

PRODUCTS AVAILABLE FOR DELIVERY NOW!

HEAVY DUTY .75” INCHES HIGH

FOR #3, #4 & #5 REBARS


DOUBLE MAT SYSTEM FROM 2” TO 8”


FOR #3, #4, #5, #6, #7 & #8 BAR SIZES

PRODUCTS AVAILABLE FOR DELIVERY NOW!

STANDARD CROWN 1 (1.5”,2.0”,2.5” and 3.0”) INCHES HIGH FOR #2, #3, #4
REBARS & 6x6
-
10x10 WIRE MESH .

STANDARD CROWN 2 (2.0”to 8” INCHES HIGH FOR #3, #4 and #5 REBARS






PRODUCTS AVAILABLE UPON REQUEST

FROM JAB PLASTIC PRODUCTS CORP.



SINGLE MAT CHAIR FROM .75” TO 8”


FOR #3, #4, #5 BAR SIZES



DOUBLE MAT CHAIRS FROM 2” TO 14”


FOR #3, #4, #5, #6, #7 & #8 BAR SIZES





MEETS CODES/STANDARDS REQUIREMENTS



MEETS STANDARD PRACTICE REQUIREMENTS



SURPASSES EXPECTED CONSTRUCTION LOADS



AVOID CORROSION STAINS



PROVIDES REQUIRED TIE
-
UP REDUCING LABOR


INTENSIVE COST



COST SAVINGS



COMPETITIVE COST

JAB Plastic Snap On and Support System.

“The new way to improve the old way”



JORGE ALFONSO

PRESIDENT

CELLULAR PHONE: (210) 859
-
4110

FAX NUMBER: 1(888) 836
-
4068

FOR INFORMATION ABOUT OUR
PRODUCTS PLEASE CONTACT:


Jab Plastics Chairs Products

• 1.5” Plastic Concrete Chair

• 2.5” Plastic Concrete Chair

• 1/2” Plastic Anchor Bolt Cap

• 5/8” Plastic Anchor Bolt Cap


The
new way

to improve the old way







JAB PLASTIC PRODUCTS CORP.
P.O.Box

11528 Austin , TX 78711
-
11528




www.jabplastic.com