the jab plastic products corp. technical presentation ibc requirements, cont. •section 1907.6 –...

THE JABPlastic Products Corp.Plastic Products Corp.Technical Presentation

WHAT DO CURRENT DESIGN CODES, STANDARDS AND MANUALS OF PRACTICES REQUIRED?

UNIFORM BUILDING CODE (UBC)

1997 UBC, VOLUME 2 – STRUCTURALENGINEERING DESIGN PROVISIONS

• Chapter 19, Section 1907.5 – PlacingReinforcement

• Chapter 19, Section 1907.6 – SpacingLimits for ReinforcementLimits for Reinforcement

• Chapter 19, Section 1907.7 – ConcreteProtection for reinforcement

• Same requirements as for the InternationalBuilding Code (IBC)

INTERNATIONAL BUILDING CODE (IBC)

•Section 1907.5.1 – Bar Support:Reinforcement bar shall be accuratelyplaced and adequately supported beforeconcrete is placed, and shall be securedagainst displacement within tolerances.

• Section 1907.5.2 – Tolerances:For Slab depth, d 8 inches;

d, ± 3/8 inchconcrete cover, – 3/8 inch

For Slab depth, d > 8 inches;d, ± 1/2 inchconcrete cover, - 1/2 inch

Tolerance for Cover shall not exceedminus 1/3 the minimum concrete coverrequired by the approved plans orspecifications.

IBC REQUIREMENTS, CONT.

•Section 1907.6 –Minimum space between bars in slab mustcomply with ACI 318, Section 7.6.

Smin. horizontally or vertically = One BarDiameter or 1 inch

• Section 1907.7.1 –Minimum concrete cover for non pre-stressedcast in place concrete:

Concrete permanently expose and castagainst soil – 3”Concrete expose to soil or weather:

For #6 through #18 Bar – 2”For #5 & W31 or D31 orsmaller – 1½”

IBC REQUIREMENTS, CONT.

Concrete not expose to weather or incontact with soil:

For slab - #11 bar orsmaller - ¾ inch

AMERICAN ASOCIATION OF STATE

• Standard Specification, Division I – Design,Section 8.21 provides a minimum distancebetween reinforcement bars:

AMERICAN ASOCIATION OF STATE HIGHWAY AND TRANSPORTATION OFFICIALS (AASHTO)

For bridges’ cast in place concrete slab:

Smin. = 1½ Bar Diameter or1½ Max. Diameter ofCoarse Aggregate or

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

Coarse Aggregate or1½ 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”


Concrete slabs exposed to mild climates:Negative reinforcement – 2”


Negative reinforcement – 2”Positive reinforcement - 1”

Concrete slabs without positive corrosionprotection and frequently exposed todeicing salts:

Negative reinforcement – 2½”Positive reinforcement - 1”


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 reinforcementbars – requires:

• Tie-up all reinforcement bar intersectionaround the perimeter of the steel mat.

•Tie-up every two (2) feet maximumcenter to center or at any otherintersection, the greater of the two,for the rest of the bar intersections.

• Section 9.6.2 – “reinforcement bar could


• Section 9.6.2 – “reinforcement bar couldbe supported on any approvedmechanism.

• Use sufficient supports to maintain thesteel bar in position in order to keepthe distance between bars and forms orthe slab surface within tolerance - ¼ inchof specified on plans or specifications.

•The weight of workers and equipmentsmust be supported against the forms notagainst the reinforcement bars.

• CONSTRUCTION INSPECTION MANUALFOR REINFORCED CONCRETE STRUCTURESBY THE AMERICAN CONCRETE INSTITUTE(ACI SP-2 (99))

MANUALS OF STANDARD PRACTICES INTHE CONSTRUCTION INDUSTRY

(ACI SP-2 (99))

• STANDARD PRACTICES FOR REINFORCINGSTEEL DETAILING BY THE CONCRETEREINFORCING STEEL INSTITUTE (CRSI)

• Steel rebar shall be firmly supported in place.• Reinforcement supports shall be of adequatecapacity and sufficient chairs be placed at theright locations to support the reinforcementsteel and the construction loads at which it willbe subject to prevent the sagging of the steel


be subject to prevent the sagging of the steeland reducing the distance between the steeland the forms or earth base.

• Allow the use of plastic chairs among othermaterials. Do not use rocks, wood blocks orother materials not approved for rebar support.

• In general, support horizontal bars at every5 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 orstainless steel chairs.

STANDARD TESTS PERFORMED ONJAB SNAP-ON & SUPPORT SYSTEM.JAB SNAP-ON & SUPPORT SYSTEM.

TEST #1 (COMPRESSION)

Figure 3 – Arrangement Used during the Compression Test

350

400

450

500

550

600

650

700

750

Lo

ad (

Lb

s)

PLASTIC CHAIR FOR 1.5" CONCRETE COVER

Test # 2 Pmax = 486 Lbs - Type 2 Failure


Test #3 Pmax = 550 Lbs - Type 2 Failure

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

-50

0

50

100

150

200

250

300

350

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

Lo

ad (

Lb

s)

Displacement (in)



300

350

400

450

500

550

600

Lo

ad

(L

bs

)

PLASTIC CHAIR FOR 1.5" CONCRETE COVER




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

0

50

100

150

200

250

300

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

Lo

ad

(L

bs

)

Displacement (in)




TEST #2 (SEGREGATION)

Core Sample - Chair 1.5”

Core Sample - Chair 2.5”

Core Samples


TEST #3 (SLAB BENDING)

For the test, three (3) reinforced concrete slabs withmeasurements of ten (10) feet long, four (4) feet wide and four(4) inches thick were built. The objective of the test was tolocate the chairs within the slabs in similar conditions at whichit will be subjected under real or practical ones, and a load testbe performed to the slabs to determine if the use of the JABplastic chairs favor the development of localized cracks orfissures around them or the development of any unexpectedcrack pattern along the width of the slab. The three (3)specimens built to determine the crack pattern differ from each

SLAB BENDING TEST

specimens built to determine the crack pattern differ from eachother in the amount of steel or steel ratio used. For the slabnumber 1, four (4) - #3 rebar were used. For the slab number2, five (5) - #3 rebar were used and for the slab number 3,seven (7) - #3 rebar were used. With the amount of steelused, the slab #1 can resist under service load condition inaddition to its own weight, 20 pounds/ft2 of live load, the slab#2 can resist 30 pounds/ft2 of live load and the slab #3 canresist 40 pound/ft2.

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 bought to a local concrete manufacturer. The maximum size of the coarse aggregate used for this concrete was ¾” nominal diameter. The average of six (6) cylinders, concrete compressive strength (f’c) was 2,310 psi at 28 days. Even though this f’c resulted way inferior to the ones normally specified in common construction for structural members (3,000 psi), it does represent a critical and probable condition at the field when the quality of the concrete is poor or the same has not been adequately cure.

Figure 10 – Block load application sequence used during the testing

Figure 10 shows the number marks drawn to identify the sequence and the location of the blocks within 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 11 shows one of the reinforced concreteslabs during the loading procedure. Before startingthe test, various blocks of 6” x 8” x 16” were weightedand an average weight was calculated to compute theamount of blocks needed for each one of thespecimens. Based on this criteria and that eachblock weight in average 30 pounds, 27 blocks werelocated over slab #1, 40 blocks were located over slab#2 and 54 blocks were located over slab #3. Thesearrangements simulate the corresponding live loads ofapproximately 20 pounds/ft^2, 30 pounds/ft^2 and 40pounds/ft^2, respectively.

Figure 12 – Crack Pattern on the Central Zone of Slab 3

Figure 12 illustrates the cracks pattern observed during thetests. On each of the slabs, the cracks begin to appear when thefirst 20 blocks were installed on top of the slabs. The cracksappear on or near the center and extended all over the width ofslab. The zones, where the plastic chairs were located, werecautiously observed. No crack concentrations were foundaround the chairs or along the slab where the chairs werelocated. No crack patterns different from what normally canbe found in reinforced concrete slab with steel wire or cementmortar (“limbers”) rebar supports subject to bending wereobserved.

The difference found between each one of the specimens wasnot in the crack pattern but in the amount of cracks found along thewidth of the slab and the measurement (width) of the crack. Thedifference was expected since the load applied was duplicated fromslab #1 to slab #3.


TEST #4 (FILTRATION)

Figure 13 – Arrangement Used during the Filtration Tests

Figure 14 – Bottom View of Concrete Slab alter 10 days Figure 14 – Bottom View of Concrete Slab alter 10 days

With the objective of evaluating if placing the JAB plastic chairsinstead of the metallic or mortar supports could contribute todevelop a localized filtration condition in the slab, a test wasspecifically designed to evaluate the effect of the plastic chairs inthe filtration pattern. The test consists in maintaining at least acolumn of water of 1.5 inches over the slab for ten (10) days.

Slab Filtration Test

column of water of 1.5 inches over the slab for ten (10) days.During this period of time, the filtration pattern was visuallyobserved, evaluating specifically if around the zones where theplastic chairs were located, the water filtration was somehowincreased as compare to other areas. Figure 13 shows thearrangement used for the tests. Figure 14 shows that after 10days of maintaining the top portion of the slab submerge inwater, no filtration marks were noticed around the location ofthe chairs neither along any of the cracks under the slab. Thedaily observation made under the slab during the preceding 9days concurs with the final observation at day 10 of the test.

JAB SNAP-ON & SUPPORT SYSTEMINSTALLATION PROCEDURES

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

– TO AVOID SAGGING OF THE REBAR LOCATE CHAIRS AT A DISTANCE NOT FARTHER APART 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 DIRECTION

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 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 TYPES OF STRUCTURAL SLABS AND SLAB ON GROUND

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 HIGHFOR #3, #4 & #5 REBARS


HEAVY DUTY .75” INCHES HIGHFOR #3, #4 & #5 REBARS

•DOUBLE MAT SYSTEM FROM 2” TO 8”•FOR #3, #4, #5, #6, #7 & #8 BAR SIZES


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 REQUESTFROM JAB PLASTIC PRODUCTS CORP.

• SINGLE MAT CHAIR FROM .75” TO 8” •FOR #3, #4, #5 BAR SIZES•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

JAB Plastic Snap On and Support System.“The new way to improve the old way”

• MEETS STANDARD PRACTICE REQUIREMENTS• SURPASSES EXPECTED CONSTRUCTION LOADS• AVOID CORROSION STAINS• PROVIDES REQUIRED TIE-UP REDUCING LABORINTENSIVE COST

• COST SAVINGS• COMPETITIVE COST

JORGE ALFONSOPRESIDENTCELLULAR PHONE: (210) 859-4110FAX NUMBER: 1(888) 836-4068

FOR INFORMATION ABOUT OUR PRODUCTS PLEASE CONTACT:

FOR TECHNICAL INFORMATION PLEASE FOR TECHNICAL INFORMATION PLEASE CONTACT:

NOEL ALFONSODIRECTOR OF ENGINEERING & TECHNICAL SUPPORTCELLULAR PHONE: (480) 201-1547

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

the jab plastic products corp. technical presentation ibc requirements, cont. •section 1907.6 –...

Documents