Title: Shape Effect of FRP Stay-in-Place Structural Forms on Durability under Freeze-Thaw Cycles

Author(s): Raouf Boles and Amir Fam

Publication: Symposium Paper

Volume: 322

Issue:

Appears on pages(s): 2.1-2.16

Keywords: durability, freeze-thaw, stay-in-place forms, FRP, concrete, bond

DOI: 10.14359/51706953

Date: 6/18/2018

Abstract:
This study investigates the effect of aggressive regime of 300 freeze-thaw (FT) cycles, at a core temperature range of +5 oC (+41 oF) to -18 oC (-0.4 oF) on the structural behaviour and bond integrity of concrete beams cast onto glass fiber reinforced polymer (GFRP) stay-in-place (SIP) structural forms. The study aims at comparing two configurations of the SIP forms, namely a flat plate with T-shape ribs and a corrugated plate, under the potential ‘frostjacking’ effect arising from FT cycles. The study explored specimens with no surface treatment, wet adhesive bonding to freshly cast concrete, and bonded coarse aggregates to enhance roughness of SIP form. It was clearly shown that flat-ribbed form specimens are superior to the corrugated form ones, as no loss in strength occurred after the FT exposure, whereas the corrugated form specimens lost 18-21%. This is attributed to the anchorage advantage provided by the T-shape rib embedment into concrete. Specimens with untreated corrugated forms showed strengths that are only 21-26% of treated ones. For flat-ribbed form specimens, the one with untreated form had 44% the strength of that with bonded aggregates.