Concrete cover effect on the bond of GFRP bar and concrete under static loading

Abstract

Paper presents assessment of bond behaviour between GFRP bars and concrete, investigated through set of centric and eccentric pull-out specimens. Main parameters under investigation are 1) bar external surface, 2) concrete mechanical properties and 3) concrete cover. Corresponding tests with steel reinforcement are performed for comparison in some cases. DIC technique was used for recording and evaluating of strain field on frontal side of eccentric specimens. Consequently, cracking patterns and local bond behaviour are described in details. Increasing of concrete mechanical properties always enhanced bond strength and delayed cracking of concrete cover. Ribbed GFRP bars showed excellent bonding performance when combined with low concrete cover. Their low splitting tendency and specific rib geometry developed better bond behaviour in case of eccentric tests, which showed the possibility of a proper prediction of the bonding behaviour of structural components

Bond between glass fibre reinforced polymer bars and high - strength concrete

“…As can be seen in Figure 16, GFRP (type B) bars with 12.7 mm bar diameters showed bond strengths that were 2.3%, 9%, 10.4% and 4.5% lower than those developed by 9.5 mm bar diameters for the embedment lengths of 2.5, 5, 7.5 and 10 times the bar diameter, respectively, with an average reduction of 6.5%. As for 15.9 mm diameters, these percentages were 4.1%, 18.5%, 15.2% and 0.6% less than those developed by 9.5 mm diameters for the same embedment lengths, with an average reduction of 9.6%. For high-strength concrete pullout cubes, it was noticed that a reduction rate in bond strength reduced with increasing the bar diameter for all embedment lengths.…”

“…According to the previous experimental investigations [1,2,4,5,[16][17][18][19][20], it was found that bond strength of GFRP bars in conventional concrete depends on several parameters, such as bar diameter, embedment length, compressive concrete strength, surface configuration, bar type, concrete cover, bar position and transverse reinforcement. Table 1 summarizes the parameters that influence the bond strength considered in the design guidelines (ACI 440.1R [21], CSA-S806 [22], CSA-S6 [23] and JSCE [24]).…”

Frischbetondruck in Elementwänden mit integriertem Dämmstoff

“…Mit der Annahme einer wirklichkeitsnahen Frischbetondruckbeanspruchung können die Schalendicken und damit die Gesamtwandstärke reduziert werden. Dies begünstigt zusätzlich den Einsatz von dauerhaften Bewehrungsmaterialien aus faserverstärkten Kunststoffen , die nur noch sehr geringe Betondeckungen fordern und aufgrund der Korrosionsproblematik von Betonstahl immer mehr an Bedeutung gewinnen.…”

Experimental Study on the Bond Performance between Fiber‐Reinforced Polymer Bar and Unsaturated Polyester Resin Concrete

“…e bond behavior between FRP bar and ordinary concrete has been widely studied in the literature [8][9][10][11][12][13][14]. A series of pull-out tests were conducted by Hao et al [8] on the effects of rib spacing and rib height of GFRP bar on the bond strength of GFRP bar and ordinary concrete.…”