Joints and Joint Seals

8/3/2019 Joints and Joint Seals

1/75

www.aboutcivil.com

JOINTS AND JOINT SEALS

Building Construction and design

Jahangir MIRZA

Mcanique, mtallurgie et civilInstitut de recherche dHydro-Qubec

Montreal, Quebec

Canada

2007UET Peshawar, Pakistan


2/75

www.aboutcivil.com

Presentation OUTLINES Expansion joints

Contraction or control joints

Construction joints

Joint seals - purpose

Types of sealants Associated materials primers, adhesives, backer rod

Effect of various parameters on the installation of joint seals

Results

Conclusions

Recommendations


3/75

www.aboutcivil.com

EXPANSION JOINT

A structural separation between

building elements that allowindependent movement without

damage to the assembly


4/75

www.aboutcivil.com

EXPANSION JOINT


5/75

www.aboutcivil.com

EXPANSION JOINT


6/75

www.aboutcivil.com

EXPANSION JOINT


7/75

www.aboutcivil.com

CONTRACTION OR CONTROL JOINT

A formed, sawed, tooled, or assembled joint

acting to regulate the location and degree of

cracking and separation resulting from thedimensional change of different elements of

structure. The joint is usually installed in

concrete and induce controlled cracking at

pre-selected locations or where a

concentration of stresses is expected.


8/75

www.aboutcivil.com

CONTRACTION OR CONTROL JOINT
http://www.radongas.com/images/seal_clean_exp_crack.jpghttp://www.radongas.com/images/seal_clean_exp_crack.jpg


9/75

www.aboutcivil.com

CONSTRUCTION JOINT

Joints placed at points of

ending and beginning ofconstruction for provision of

a smooth transition between

pours.


10/75

www.aboutcivil.com

CONSTRUCTION JOINT


11/75

www.aboutcivil.com

JOINT SEALS - PURPOSE

Accommodate joint movementAccommodate joint movement

Prevent infiltration of solids (dust, sand, etc)Prevent infiltration of solids (dust, sand, etc)

Prevent ingress of water and salt solutionPrevent ingress of water and salt solution


12/75

www.aboutcivil.com

TYPES OF SEALANTS

Field- molded Sealants (FMS)

Preformed Sealants


13/75

www.aboutcivil.com

Field- molded SealantA liquid or semi-solid material

molded into the desired shape in thejoint into which it is installed.


14/75

www.aboutcivil.com

Field- molded Sealant


15/75

www.aboutcivil.com

Field- molded Sealant


16/75

www.aboutcivil.com

Field- molded Sealants

Oil-based Sealants

Mastics and Thermoplastics

Polyurethane Sealants

Polysulphide Sealants

Silicone Sealants

Epoxy Sealants


17/75

www.aboutcivil.com

Polyurethane sealants

1-component cured by air moisture

2-components cured by internal chemical

reaction

Non-sag, pouring, high Shore hardness (foot

traffic), fast curing for bridge decks, highways,

runways

Tough, non-staining, durable and flexible

Properties differ from manufacturer to

manufacturer


18/75

www.aboutcivil.com

Polysulphides

1- and 2-components

Non-sag and pouring types Good resistance to weather and ageing

Not deform at low temperatures


19/75

www.aboutcivil.com

Silicones

1-component

Low shrinkage

Good strength and excellent resistance to

the effects of sunlight, ozone, UV

Tough, non-staining, durable and flexible

Properties differ from manufacturer to

manufacturer


20/75

www.aboutcivil.com

Characteristics of field-

moulded SealnatsCharacteristics Polyurethane Polysulphides Silicones

Movement

Capability

Types

25%

1- component,

moisture-cured

2- component,

chemically-cured

12% to 25%

1- component,

moisture-cured

2- component,

chemically-cured

12% to 25%

1- component,

moisture-cured

2- component,

chemically-cured


21/75

www.aboutcivil.com

Characteristics Polyurethane Polysulphides Silicones

Advantages High elasticity

Very tough, good

for traffic surfaces

Applicable to

large moving

joints

Excellent

adhesion

High elasticity

Excellent flexibility

Applicable to large

moving joints

Excellent

adhesion

High elasticity

Good flexibility

Applicable tolarge moving

joints

Excellent

adhesion


22/75

www.aboutcivil.com

Characteristics Polyurethane Polysulphides Silicones

Disadvantages

and limitations

Application

temperature over4C

Primer required

Ventilation required

during application

and curing

Application

temperature over 4C

Primer required

Bad odor during

application and

curing

Applied as low

as -18 C

Some require

Primer

Ventilation

required during

application and

curing

Relatively

Expensive


23/75

www.aboutcivil.com

Comparison of 2-Component and 1-Component Sealants

Chemically cured

Cure fast within joint

Develop Elastic Properties

quickly

Maintain tension within a

short period of time

Usually moisture-cured

Cure slowly,especially in

deep joints

Take a long time to

develop elastic properties

May not maintain

tension,especially when

placed at low

temperatures

2-Component Sealants 1-Component Sealants


24/75

www.aboutcivil.com

Could be used in joints

more than 12 mm deep

Normal width-depth ratio

is 1:1 for the joint widths

up to 12 mm; if greater 2:1

Require mixing apparatus

Possibility of sealantwastage

Problem of clean

apparatus

Used in joints to a minimum of6mm and maximum of 12 mm

Width-depth ratio is 1:1for the

joint widths up to 12 mm; if

greater 2:1, maximum remains12mm

Easy to use

Little possibility of wastage

No cleaning required

Comparison of 2-Component and 1-Component Sealants

2-Component Sealants 1-Component Sealants


25/75

www.aboutcivil.com

PREFORMED SEAL

Seal functionally pre-shaped by

the manufacturer so that aminimum of field fabrication is

required prior to installation


26/75

www.aboutcivil.com

PREFORMED SEALS


27/75

www.aboutcivil.com

PREFORMED SEALS


28/75

www.aboutcivil.com

PREFORMED SEALS


29/75

www.aboutcivil.com

PREFORMED SEAL


30/75

www.aboutcivil.com

PREFORMED SEALS*

Neoprene Seals

Silicone Rubber Seals

Closed-cell, Low Density Seals

Permanently Elastic Seals

* All require organic adhesives

Bonding agent for installation


31/75

www.aboutcivil.com

ASSOCIATED MATERIALS

Primers

Adhesives

Backup or Backer Rod


32/75

www.aboutcivil.com

Primers

Prime concrete and other surfaces to obtain

proper adhesion and maximum performance

of FMS.

Applied on surfaces exposed to immersion

because of viscous sealant inability to flowinto small pores

Install sealant while primer tacky

For the same seal, primer differ for different

substrates

Use manufacturers recommendations


33/75

www.aboutcivil.com

Adhesives

Facilitate installation and improve adhesion ofseal to substrate

All preformed seals require adhesives (acts as

bonding agent)

1- and 2-components (1-component moisture

curing PUR, 2-components 100% modified epoxy)

Applied on pre-sandblasted or pre-cleaned joint

surfaces before installation of preformed seals Special lubricant adhesives, which prime and

bond, to improve seal-to-joint face contact


34/75

www.aboutcivil.com

BACKUP MATERIALS (BACKER ROD)

A compressible material used in

the bottom of the seals

reservoirs to reduce the depthof the seal thus improving its

shape factor. This also serves

to support the seal against sagor indentation.


35/75

www.aboutcivil.com


Good joint design and optimumperformance of seals require proper

selection and use of backup rod.

Soft and flexible and not absorb water

Compressible material not be forced out

as joint closes and recover as joint opens

Not break or twist in the joint


36/75

www.aboutcivil.com


In all case, backer rod should be at least 25%

greater than joint width

Functions:

Control seal depth in the joint

Assists seal tooling in the joint

Serves as joint breaker to prevent seal bonding to the

back of joint

Acts as temporary joint filler

Supports seals in horizontal joints

May function as secondary protective barrier after

applying sealant


37/75

www.aboutcivil.com



38/75

www.aboutcivil.com

SUMMARY JOINT SEALS


39/75

www.aboutcivil.com

EFFECT OF VARIOUS PARAMETERS ON

THE INSTALLATION OF JOINT SEALS

Joint and Joint Seal Configurations

Installation Temperature Effect of Stresses

Effect of Moisture

Surface Preparation General Comments


40/75

www.aboutcivil.com

Joint and Joint Seal Configuration

Joint width gap and its %age movementaffects seal installation

Installing seals difficult in narrow joints wide enough to allow easy installation and

accommodate movement

Joint edges elevated and FMS concave or

semicircular shape (Fig.)


41/75

www.aboutcivil.com



42/75

www.aboutcivil.com


FMS poor resistance to abrasion

easily damaged (road & foot traffic),

recess sealants away from abrasion

Highway and hydraulic structures

keep sealant upper surface 8 to 20

mm below concrete surface

Joints in spillways with high water

flow, keep surface smooth and Q Flush


43/75

www.aboutcivil.com


Install proper amount of FMS to therecommended depth

1-component FMS, minimum depth 6

mm and maximum 12 mm, for 2-component FMS, depth could be

increased (Tab.)

1-component FMS longer set time

(> 3 days, depends on temperature)

than 2-components (1 day or less)


44/75

www.aboutcivil.com

Width/Depth relationship for FMS

Joint width mm Depth of sealant in jointsmm

Concrete Steel

Min. 66 to 12

12 to 24

Over 24 *

Max. 50 *

6Same as width

12

Width/2

Width/2

66

Width/2

Width/2

Width/2

* For moisture-cured field-moulded sealants, the maximum depth should be 12mm.


45/75

www.aboutcivil.com

Installation Temperature Temperature of structural elements at the

time of seal installation determines thetype of stress on the seal

In hot summer day, joint gap between two

structural elements - at or near minimum.Seal undergoes extension next winter

In cold winter, reverse compression

Between 2 extremes, seal under tensileand compressive stresses

Install sealants in spring or in fall


46/75

www.aboutcivil.com

Effect of Stresses

Temperature and field conditions simultaneouslyplace more than 1 type of stresses

Winter seal is coldest, hard and least able toaccommodate movement

May also experience shear stresses upward anddownward deflections of concrete slabs underheavy load

Stresses increase with time

Use low modulus FMS or very flexible preformedseals have good movement capabilities

1-component FMS applied in winter or not???


47/75

www.aboutcivil.com

Installation Temperature


48/75

www.aboutcivil.com

EFFECT OF MOISTURE

Moisture major problem to mostadhesives

Adhesives (epoxy) polar, water diffuses in

and swells them

Decrease in bond strength and cohesive

failure

Design structure or adhesive morehydrophobic


49/75

www.aboutcivil.com

Surface Preparation

Adequate surface preparation -remove dirt and other foreign matter

Surface cleaning techniques dependon application- structure vs. highway

or new construction vs resealapplication No single technique for all applications

New concrete construction wirebrush followed by high-pressure air-blast


50/75

www.aboutcivil.com

Surface preparation

Steel joints fine sandblasting then highpressure air blast

Highway joints sawed High-pressure water;

wire brushing then high-pressure air blasting

Reseal applications difficult to remove oldseals. Knife cutting, sand blasting then high-pressure air blasting

Best to widen the joint by sawing

Never use solvent, dissolving liquids or heat not good adhesion with concrete


51/75

www.aboutcivil.com

General comments

Seals must maintain rubber properties

Joint seals - capacity to changes in joint

dimensions Seal shape changes but volume remains

constant

Must keep proper width-to-depth ratio


52/75

www.aboutcivil.com

FIELD TESTS

Concrete-Concrete Joints(Parking

Structure at IREO)

Four FMS Sikaflex 2C (2-comp. PUR)

Duoflex (2-comp.PS)

NP1 (1-comp.PUR)

Dow Corning 888 (1-comp.Silicone)


53/75

www.aboutcivil.com

FIELD TESTS

Six Preformed Seals 3 Neoprene

2 Foam Type

1 Silicone

Steel-Steel Joints (Bridge with Heavy Traffic)

Same Four FMS

Same Six Preformed Seals but withdifferent Dimensions


54/75

www.aboutcivil.com

Concrete driveway

Lifti b id t l j i t


55/75

www.aboutcivil.com

Lifting bridge steel joints


56/75

www.aboutcivil.com

FMS A after one winter


57/75

www.aboutcivil.com

FMS J after one winter

P f d l M & P ft i t


58/75

www.aboutcivil.com

Preformed seals M & P after one winter


59/75

www.aboutcivil.com

Preformed seal Q after one winter

RESULTS ON FIELD PERFORMANCE


60/75

www.aboutcivil.com


Field-molded Sealants

Joint Sealants Concrete Joints Steel Joint

Sikaflex 2C (2-comp.) Poor Adhesion Excellent Bond

Duoflex (2-comp.) Very Poor Adhesion Excellent Bond

NP1 (1-comp.) Excellent Bond,Extension Poor Adhesion

>300%

Silicone(1-comp.) Excellent Bond,Extension Poor Adhesion

>300%

S S O O C


61/75

www.aboutcivil.com


PREFORMED SEALS

Generally performed well in the field BUT:

Costly

Installation techniques difficult;

Seal maintenance difficult; and

Difficult to replace after a portion of theseal is damaged


62/75

www.aboutcivil.com

Guidelines - JOINTS

Position of joints (crest, up- and down-streams, road, etc.)

Current temperature

Cause of joint degradation Objectives of repair

Environment (traffic, humid, wetting-drying,

freezing-thawing, etc.) Width and depth of joint

New joints versus repair/replacement

G id li GENERAL


63/75

www.aboutcivil.com

Guidelines - GENERAL

Experienced persons Joint conditions (good conditions, dry,

remove dust and all other dirt)

Primers (compatible with steel and

concrete)

Installation temperatures (best in spring or

fall minimum seasonal movement)

G id li SEALANT APPLICATIONS


64/75

www.aboutcivil.com

Guidelines SEALANT APPLICATIONS

Pouring type horizontal joints

Non-sag vertical and inclined joints

Concave surface (traffic, abrasion)

Flush surface (cavitation)

Curing

1-component (7 to 72 hrs, final 3 to 21 days)

2-component (6 to 8 hrs. final 3 to 21 days) Temperature

Humidity

G id li SPECIFIC


65/75

www.aboutcivil.com

Guidelines SPECIFIC

Concrete joints severely deteriorated Concrete joints and sealants deteriorated

Concrete joints on top of delicateequipment

Asphalt-asphalt or asphalt-concrete joints

Steel-steel joints or steel-concrete joints

J i t d J i t S l C fi ti


66/75

www.aboutcivil.com

Joint and Joint Seal Configurations


67/75

www.aboutcivil.com


68/75

www.aboutcivil.com


69/75

www.aboutcivil.com


70/75

www.aboutcivil.com


71/75

www.aboutcivil.com

Concrete joint over sensitive equipment


72/75

www.aboutcivil.com


73/75

www.aboutcivil.com


74/75

www.aboutcivil.com


75/75

THANKS

ANY QUESTIONS???

Joints and Joint Seals

Documents

Transcript of Joints and Joint Seals