Interlaboratory evaluation of Tg of ambient-cured epoxies used in civil infrastructure

Charles E. Bakis; Luke A. Bisby; Maria M. Lopez; Sarah E. Witt; Tarek Alkhrdaji

Interlaboratory evaluation of T_g of ambient-cured epoxies used in civil infrastructure

Charles E. Bakis, Luke A. Bisby, Maria M. Lopez, Sarah E. Witt, Tarek Alkhrdaji

Research output: Chapter in Book/Report/Conference proceeding › Conference contribution

Abstract

Ambient-cured epoxies used to bond high strength continuous fibers to concrete for strengthening purposes can have glass transition temperatures (T_g) that are not only close to the service temperature but can also change over time as a function of environmental conditions. While the design ramifications of using such an epoxy resin with an evolving T_g close to the service temperature are unclear and difficult to predict, recommended methods for assigning a T_g for such resins are nonetheless needed. In the present investigation, an interlaboratory evaluation of T_g characteristics of several ambient-cured epoxy resins using dynamic mechanical analysis (DMA) and differential scanning calorimetry (DSC) was carried out. The need for standardized specimen conditioning prior to T_g measurement is demonstrated. Of the three DMA T_g methods employed, the tan δ method provided the lowest standard deviation. Because of its reliability and its roots in mechanical testing, the DMA tan δ method applied during a single temperature up-ramp is recommended for assigning T_g.

Original language	English (US)
Title of host publication	Proceedings of the 7th International Conference on FRP Composites in Civil Engineering, CICE 2014
Editors	Raafat El-Hacha
Publisher	International Institute for FRP in Construction (IIFC)
ISBN (Electronic)	9781771363082
State	Published - Jan 1 2014
Event	7th International Conference on FRP Composites in Civil Engineering, CICE 2014 - Vancouver, Canada Duration: Aug 20 2014 → Aug 22 2014

Publication series

Name	Proceedings of the 7th International Conference on FRP Composites in Civil Engineering, CICE 2014

Other

Other	7th International Conference on FRP Composites in Civil Engineering, CICE 2014
Country/Territory	Canada
City	Vancouver
Period	8/20/14 → 8/22/14

All Science Journal Classification (ASJC) codes

Polymers and Plastics
Civil and Structural Engineering

Cite this

Bakis, C. E., Bisby, L. A., Lopez, M. M., Witt, S. E., & Alkhrdaji, T. (2014). Interlaboratory evaluation of T_g of ambient-cured epoxies used in civil infrastructure. In R. El-Hacha (Ed.), Proceedings of the 7th International Conference on FRP Composites in Civil Engineering, CICE 2014 (Proceedings of the 7th International Conference on FRP Composites in Civil Engineering, CICE 2014). International Institute for FRP in Construction (IIFC).

Bakis, Charles E. ; Bisby, Luke A. ; Lopez, Maria M. et al. / Interlaboratory evaluation of T_g of ambient-cured epoxies used in civil infrastructure. Proceedings of the 7th International Conference on FRP Composites in Civil Engineering, CICE 2014. editor / Raafat El-Hacha. International Institute for FRP in Construction (IIFC), 2014. (Proceedings of the 7th International Conference on FRP Composites in Civil Engineering, CICE 2014).

@inproceedings{70bb6a7e7d11497ab68c391dd0cb5097,

title = "Interlaboratory evaluation of Tg of ambient-cured epoxies used in civil infrastructure",

abstract = "Ambient-cured epoxies used to bond high strength continuous fibers to concrete for strengthening purposes can have glass transition temperatures (Tg) that are not only close to the service temperature but can also change over time as a function of environmental conditions. While the design ramifications of using such an epoxy resin with an evolving Tg close to the service temperature are unclear and difficult to predict, recommended methods for assigning a Tg for such resins are nonetheless needed. In the present investigation, an interlaboratory evaluation of Tg characteristics of several ambient-cured epoxy resins using dynamic mechanical analysis (DMA) and differential scanning calorimetry (DSC) was carried out. The need for standardized specimen conditioning prior to Tg measurement is demonstrated. Of the three DMA Tg methods employed, the tan δ method provided the lowest standard deviation. Because of its reliability and its roots in mechanical testing, the DMA tan δ method applied during a single temperature up-ramp is recommended for assigning Tg.",

author = "Bakis, {Charles E.} and Bisby, {Luke A.} and Lopez, {Maria M.} and Witt, {Sarah E.} and Tarek Alkhrdaji",

year = "2014",

month = jan,

day = "1",

language = "English (US)",

series = "Proceedings of the 7th International Conference on FRP Composites in Civil Engineering, CICE 2014",

publisher = "International Institute for FRP in Construction (IIFC)",

editor = "Raafat El-Hacha",

booktitle = "Proceedings of the 7th International Conference on FRP Composites in Civil Engineering, CICE 2014",

note = "7th International Conference on FRP Composites in Civil Engineering, CICE 2014 ; Conference date: 20-08-2014 Through 22-08-2014",

}

Bakis, CE, Bisby, LA, Lopez, MM, Witt, SE & Alkhrdaji, T 2014, Interlaboratory evaluation of T_g of ambient-cured epoxies used in civil infrastructure. in R El-Hacha (ed.), Proceedings of the 7th International Conference on FRP Composites in Civil Engineering, CICE 2014. Proceedings of the 7th International Conference on FRP Composites in Civil Engineering, CICE 2014, International Institute for FRP in Construction (IIFC), 7th International Conference on FRP Composites in Civil Engineering, CICE 2014, Vancouver, Canada, 8/20/14.

Interlaboratory evaluation of T_g of ambient-cured epoxies used in civil infrastructure. / Bakis, Charles E.; Bisby, Luke A.; Lopez, Maria M. et al.
Proceedings of the 7th International Conference on FRP Composites in Civil Engineering, CICE 2014. ed. / Raafat El-Hacha. International Institute for FRP in Construction (IIFC), 2014. (Proceedings of the 7th International Conference on FRP Composites in Civil Engineering, CICE 2014).

Research output: Chapter in Book/Report/Conference proceeding › Conference contribution

TY - GEN

T1 - Interlaboratory evaluation of Tg of ambient-cured epoxies used in civil infrastructure

AU - Bakis, Charles E.

AU - Bisby, Luke A.

AU - Lopez, Maria M.

AU - Witt, Sarah E.

AU - Alkhrdaji, Tarek

PY - 2014/1/1

Y1 - 2014/1/1

N2 - Ambient-cured epoxies used to bond high strength continuous fibers to concrete for strengthening purposes can have glass transition temperatures (Tg) that are not only close to the service temperature but can also change over time as a function of environmental conditions. While the design ramifications of using such an epoxy resin with an evolving Tg close to the service temperature are unclear and difficult to predict, recommended methods for assigning a Tg for such resins are nonetheless needed. In the present investigation, an interlaboratory evaluation of Tg characteristics of several ambient-cured epoxy resins using dynamic mechanical analysis (DMA) and differential scanning calorimetry (DSC) was carried out. The need for standardized specimen conditioning prior to Tg measurement is demonstrated. Of the three DMA Tg methods employed, the tan δ method provided the lowest standard deviation. Because of its reliability and its roots in mechanical testing, the DMA tan δ method applied during a single temperature up-ramp is recommended for assigning Tg.

AB - Ambient-cured epoxies used to bond high strength continuous fibers to concrete for strengthening purposes can have glass transition temperatures (Tg) that are not only close to the service temperature but can also change over time as a function of environmental conditions. While the design ramifications of using such an epoxy resin with an evolving Tg close to the service temperature are unclear and difficult to predict, recommended methods for assigning a Tg for such resins are nonetheless needed. In the present investigation, an interlaboratory evaluation of Tg characteristics of several ambient-cured epoxy resins using dynamic mechanical analysis (DMA) and differential scanning calorimetry (DSC) was carried out. The need for standardized specimen conditioning prior to Tg measurement is demonstrated. Of the three DMA Tg methods employed, the tan δ method provided the lowest standard deviation. Because of its reliability and its roots in mechanical testing, the DMA tan δ method applied during a single temperature up-ramp is recommended for assigning Tg.

UR - http://www.scopus.com/inward/record.url?scp=84924872701&partnerID=8YFLogxK

UR - http://www.scopus.com/inward/citedby.url?scp=84924872701&partnerID=8YFLogxK

M3 - Conference contribution

AN - SCOPUS:84924872701

T3 - Proceedings of the 7th International Conference on FRP Composites in Civil Engineering, CICE 2014

BT - Proceedings of the 7th International Conference on FRP Composites in Civil Engineering, CICE 2014

A2 - El-Hacha, Raafat

PB - International Institute for FRP in Construction (IIFC)

T2 - 7th International Conference on FRP Composites in Civil Engineering, CICE 2014

Y2 - 20 August 2014 through 22 August 2014

ER -

Bakis CE, Bisby LA, Lopez MM, Witt SE, Alkhrdaji T. Interlaboratory evaluation of T_g of ambient-cured epoxies used in civil infrastructure. In El-Hacha R, editor, Proceedings of the 7th International Conference on FRP Composites in Civil Engineering, CICE 2014. International Institute for FRP in Construction (IIFC). 2014. (Proceedings of the 7th International Conference on FRP Composites in Civil Engineering, CICE 2014).