Effects of coarse aggregate volume on CFRP-concrete bond strength and behavior

New equations of fibre reinforced polymers-concrete bond strength and bond-slip law based on mesoscale simulations

“…Independent test data reported in Pan et al (2007), Carloni et al (2012), Hosseini and Mostofinejad (2014), and Mostofinejad et al (2019), are used to examine the performance of the proposed models (Equations ( 13)-( 16)).…”

“…When the AF-dependent bond-slip law (Equations ( 14)-( 16)) is available, the FRP-concrete interface can then be modelled by interfacial elements with the bond-slip law as the constitutive relation, so that the complicated meso-scale simulations in previous sections are not needed (Yang et al, 2009;Yao et al, 2021). To validate the proposed bond-slip model Equations ( 14)-( 16), four specimens with different f c 0 and AF in Mostofinejad et al (2019) are simulated (see Table 5), using zero-thickness cohesive elements of type COH2D4 in ABAQUS to represent the FRP-concrete interface. Figure 15(a) shows the FE model with a 10 mm mesh size of the specimen EBR-35-0.74-2 as an example.…”

“…Figure 16(a) plots the simulated force-displacement responses together with the experimental data for the Table 5. Test versus simulated results using Equations ( 14)-( 16) of four specimens in Mostofinejad et al (2019).…”

“…Test specimen f c ' (MPa) AF (%) Experimental bond strength P u,test (kN) Simulated bond strength P u,sim (kN) P u,sim /P u, test four specimens in Mostofinejad et al (2019). The values of bond strength are compared in Table 5, with 3%-7% differences.…”

“…In this technique, a keen research interest is to clarify the mechanisms of the interfacial bond-slip behaviour between the FRP and the concrete substrate (Teng et al, 2002; Ueda and Dai, 2005). However, almost all existing theoretical and numerical studies on the debonding failure in FRP-strengthened concrete joints and structures have treated concrete as a homogeneous material (Chen et al, 2011; Jiang et al, 2023; Lu et al, 2005b; Pham and Al-Mahaidi, 2007; Yang et al, 2003) and ignored its heterogeneous nature, although limited experimental studies revealed that the meso-scale composition of a thin layer of concrete above the interface significantly affects the bond strength of FRP-concrete joints (Barham et al, 2019; Mostofinejad et al, 2019; Mukhtar, 2019; Pan et al, 2007).…”