Temporary Corrosion Protection for Strand and Influence of Vibration During Setting of Grout Dr. Andrea Schokker, Principal Investigator Edwin Salcedo, Research Assistant Jessica DeSalvo, Research Assistant Sponsored by ASBI, Florida DOT, and Texas DOT P ENN S TATE U NIVERSITY

Oils for Temporary PT Corrosion Protection Sponsored by the Texas DOT © Corrosion protection © Degree of bond reduction © Oils –Testing those used in PT & potential candidates from the metal working industry –Water source and water content –Application © No water flushing of tendons

Oils for Temporary PT Corrosion Protection © Corrosion Testing –Electrochemical Evaluation (grouted) –Ungrouted exposure testing l Outdoor exposure (through winter) l Humid exposure (controlled: 23 C, 96% RH) l Saltwater exposure (partial submersion) © Bond (pull-out) testing © Large scale bond testing

List of Oils Tested © Oil 1: Anticorit AQ 31 © Oil 2: Citcool Concentrate 33 © Oil 3: Cutting Oil NC 205 © Oil 4: Dromus ABD © Oil 5: Emulsifiable Cutting Oil © Oil 6: 5-Star Protective Coating © Oil 7: Hocut 4284-B © Oil 8: Hocut 795 © Oil 9: Lubrol 215 B © Oil 10: Nox-rust 703 D © Oil 11: Nox-rust 707 © Oil 12: Rheocrete 222+ © Oil 13: RustBan 310 © Oil 14: Rustphree 4746A © Oil 15: Rust-Veto 342 © Oil 16: Rust-Veto FB 20 © Oil 17: Tectyl 810 © Oil 18: VpCI 377 © Oil 19: VpCI 389

Corrosion Specimens Type A: Outdoor Exposure & Humidity Chamber Type B: Saltwater Exposure

Corrosion Ratings © 1- Excellent: As received from Manufacturer © 2- Very Good: No sign of corrosion or small rust spots © 3- Good: Small blisters, superficial but widely spread corrosion, pitting is unusual © 4- Satisfactory: Small blisters, uniform corrosion or wide pitting in small areas © 5- Fair: Blisters, Deep and/or wide pitting, interstitial corrosion © 6- Poor: Large blisters, trail of blisters no greater than two inches, deep and wide pitting, pitting not present in all wires, interstitial corrosion © 7- Very Poor: Large blisters, deep and wide pitting affecting over 70% of strand surface area, strong interstitial corrosion, visible large areas of steel section loss

Corrosion Performance Outdoor Exposure Humidity Chamber Saltwater Corrosion Intensity Corrosion rating after 6 months exposure Control

Exposure Duration & Intensity © Corrosion onset and intensity varies with oil type and environment O4 Performance

Pullout Test Specimens

Good bond performance Poor bond performance

Pullout Test Results (Oils with Corrosion Rating < 4) 69% 47% 42% 35%

Conclusions and Recommendations © Multiple oils produced in the U.S. provide adequate corrosion protection © Bond Reduction From Emulsifiable Oils Vary From 30% to 97% © Recommended oils for large-scale testing: OilManufacturer Corrosion Rating* Bond Reduction O3: Cutting Oil NC 205 Citgo3.8331% O4: Dromus ABD 201 Shell/Texaco3.0053% O13: Rustban 310 Esso (Europe) % O5: Emulsifiable Cutting Oil Shore Chemical % *Saltwater Exposure for 6 months

Influence of Vibration During Setting of Grout Sponsored by ASBI and the Florida DOT © Objectives –Determine if shock and vibration from construction equipment loads has a detrimental effect on grouts during set –Recommend construction traffic limitations if necessary to avoid adverse effects on grout

Bleed Testing © 30 Hz –suggested by Florida DOT based on vibration readings from pile driving – will represent higher frequencies than tendons are likely to see © 5 Hz –More representative of actual vibration in structure © Plain grout to investigate “worst case” © Prepackaged grout to investigate industry standard

Plain grout at 30 Hz (selected results)

Summary of Bleed Testing © Plain grouts –Increased bleed with early age vibration at 30 Hz –Increased set time with vibration prior to set –Little change in bleed with vibration at 5 Hz © Prepackaged grout –Very little change in bleed with vibration at 30 Hz –No change in bleed with vibration at 5 Hz

Test Program © Bond Effects –Prepackaged grout –5 Hz with 10 minutes vibration per hour –Varied vibration times –Standard PTI pull-out test

Pull-out Test Data

Vibration Results Vibrated 10 minutes each hour 34% reduction 13% reduction

Vibration Results Vibrated 10 minutes at start and finish of interval

Summary of Bond Testing © Vibration during the first few hours after grouting may influence bond © Multiple vibration incidents cause the most influence © Bond reduction minimal if vibration limited until close to set time

Recommendations © Limit vibration (construction traffic) for four hours after grouting – unless testing on the specific grout shows adequate bond at earlier ages –if limitations on construction traffic to four hours cause a scheduling problem, a case-by-case basis can be used to determine whether this reduction is critical for the application © Construction traffic should be limited for 24 hours when a plain grout is used