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Concrete Fireproofing Analysis, Evaluation and Repair Strategies

Concrete Fireproofing Analysis, Evaluation and Repair Strategies

FIREPROOFING ANALYSIS, EVALUATION AND REPAIR STRATEGIES

April 12 - 16, 2010 League City, Texas, USA

Thomas R. Kline [email protected] 281.479.0391

Picture Courtesy of Refinery Terminal Company (RTFC) Fireproofing Purpose

‹ Maintaining structural stability and integrity of steel members and vessel/pipe supports for a defined period of time when exposed to a fire

Protection

Active Passive Picture Courtesy of Refinery Terminal Fire Company (RTFC)

2 Fireproofing Basics

Material minimum thickness Restrict rate

Acceptable steel Protected core temperature at element the end of fire exposure to avoid collapse/buckling

3 Comparison of Typical ‘Hydrocarbon’ and ‘Cellulose’ Time-Temperature Curves

2500 1400

Hydrocarbon 1200 2000 F) C) ° Cellulose 1000 ° ( it (

Within 4 ss minutes 1500 800 ahrenhe s Celsiu FF 600 ee 1000

400 Degre egrees DD 500 200

0 0 0204060 80 100 120 Minutes 4 Effect Of Temperature On Strength Of

100

80 rength

60 50% reduction

riginal St @ 1000 °F 40 ent of O cc 20 Per

0 50 300 550 800 1050 1300 1550 Degrees Fahrenheit ( F) ° 5 Fire And Explosion Behavior

‹ Resistance to thermal and erosive forces ‹ Surface temperature of substrate ‹ Non-combustible ‹ Withstand effects of explosion and subsequent drag pressures

Picture Courtesy of Refinery Terminal Fire Company (RTFC)

6 Pre-Fire Durability

‹ Weather cycling and chemical tolerance ‹ Vapor permeability and low porosity ‹ Vibration resistance - compressive, tensile and flexural strength ‹ Hardness value and impact resistance ‹ Abrasion and erosion resistance ‹ Bonding strength ‹ Wash-down resistance

7 Passive Fireproofing Materials

¾ Heat absorbers Lightweight CEMENTITIOUS ¾ Hard and durable ¾ Economic Dense ¾ Easy to install and repair

Epoxy ¾ React under fire and emit gases based ¾ Form a low density carbonaceous char

Boards ¾ Can provide FIBROUS ¾ Absorb water Blankets ¾ Indoor applications

¾ Sandwich of metallic cladding, Composite COMPOSITES cementitious board, and mineral Panels or ceramic fibers ¾ Not economically feasible 8 Cementitious Concrete Materials

‹ Made with Portland or modified fire- resistant ‹ Specific weights y Dense concrete - 140 to 150 lb./ft3 y Light wei ght concret e - 25 to 80 lb. /ft3 ‹ Thermal conductivity tends to be inversely proportional to specific weight ‹ Capable of withstanding direct flame impingement up to 2000 o F (1100 o C) ‹ Alkaline passive film protects the embedded steel

9 Intumescent Epoxy Coatings

‹ Intumescent coatings react to flame or heat at around 300o Fahrenheit (149o C) by expanding int o a thi ck multi cell ul ar i nsul ati ng bl ank et . Thi s intumescent carbonaceous foam sharply limits the spread of flame and insulates the steel. ‹ Washable, aesthetically pleasing, mark resistant surface like traditional paint ‹ Provide protection from corrosion ‹ Require expertise in application and controlled conditions ‹ Comppygaratively higher cost to cementitious materials

10 Fireproofing Rating

A function of:

‹ Time and ease of evacuation ‹ Fire hazard ppyosed by substance ‹ Fire suppression capabilities

2 inches (50 mm) of cementitious products will provide a 2-hour rating (BS476 & ASTM E-119)

11 Concrete Fireproofing In Processing Units

Multilevel Equipment Structures

Pipe Racks

12 Fireproofing Deterioration

Corrosion Cracking

Risk Of Loss Of Fire P rot ecti on

Efflorescence Fire Damage

13 Embedded Structural Steel Corrosion Exposed During Fireproofing Inspection Process

14 Rust Stains Emerging From Fireproofing Indicating Early Evidence Of Steel Member Corrosion

Failed Fireproofing Due To Embedded Structural Steel Member Corrosion

15 Improperly Detailed Cementitious Fireproofing, Notice No Mesh Reinforcement

16 Severely Corroded Embedded Wire Mesh And Corroding Structural Steel Member Flanges

Severely Corroded Embedded Wire Mesh And Corroding Structural Steel Members & Connections 17 Fireproofing Deterioration Mechanism Corrosion- Corrosion Induced Delamination/ Products Cracking Spalling

Cementitious Structural Steel Fireproofing Beam/Column

Surface Shrinkage Corrosion Cracking Products

18 Fireproofing Deterioration Mechanism ()(cont.)

Structural Steel Beam/Column

Preformed Inorganic Panel Fireproofing

Corrosion Open Areas Within The “Boxed” Products Struct ural M emb er Fill s With Mo is ture And Promotes Corrosion

19 Prior Repair Shrinkage Cracked And Pipe Slide Shoe “Seized” By Corrosion

20 Fireproofing Deterioration Mechanism ()(cont.)

PIPELINE

Corros ion Bu ild-Up Structural Steel Frozen Slide Corr osi on Rotation Cementitious Fireproofing

Struct ural St eel Rotation Beam/Column 21 Condition Survey And Evaluation

‹ Assess the condition of concrete fireproofing

‹ Evaluate causes of concrete/steel distress

‹ Provide conceptual repair recommendations

22 Need For Fireproofing Restoration ‹ Safety y Possible structural collapse y Reduced /lower expected y Personnel at risk due to falling debris ‹ Insurance costs ‹ Aesthetics of damaged/falling fireproofing

23 Visual Inspection And Mapping

Note: Excavation at crack location

24 Excavation Geometry

Struct ural Steel element

Reinforcing wire mesh Structural Steel Beam

Fireproofing

Fireproofing

25 Ultrasonic Thickness Measurements

‹ Ultrasonic Thickness MtMeter ‹ Structural steel pipes, webdbbs and beams flanges ‹ AidfAccess one side of steel member

26 Measurement Analysis

Wide Flange Flange Section

Shape Thickness tf Loss (%)

Theoretical

vs

Measured t f If critical, t w remedial actions needed before...

27 Conceptual Fireproofing Repair

‹ Assemble scaffolding for elevated regions of distressed fireproofing ‹ Remove deteriorated concrete fireproofing and wire mesh avoiding damage to structural steel members ‹ Clean exposed embedded structural steel members of corrosion products ‹ Inspect members and connections for structural integrity ‹ Coat exposed structural steel section

28 Fireproofing Repair (Cont.)

‹ Install wire mesh ‹ AbltAssemble mortar-tig ht cavit y f ormwork ‹ Re-establish the cementitious fireproofing section b y usi ng “f orm and pour” pl acement techniques ‹ RfRemove formwor kftiiddk after curing period and surface grind cementitious repairs to match original fireproofing surface contours

29 Valuable Repair Aspects

‹ Turnkey investigation ‹ Attention to details ‹ Budgggpeting capabilities ‹ Corrosion protection to steel ‹ Production rates ‹ Adjustable crew size with qualified personnel ‹ High qualit y repai r mat eri al s ‹ Observe standard industry practices

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