Comparative Study of Models on Confinement of Concrete Cylinders with Fiber-Reinforced Polymer Composites

Axial compressive behavior of FRP-confined concrete: Experimental test database and a new design-oriented model

“…As was reported previously in De Lorenzis and Tepfers [4], variability in material properties of the test specimens, such as the stiffness of the FRP confining shell, the type and size of aggregates used in the concrete mix, and the mix proportions and moisture content of the concrete, contribute to the scatter found in test databases. As discussed in Section 3.4, the differences in the instrumentation of 12 the specimens and the setups used in testing them also contribute significantly to scatter.…”

“…[3,4,8,9,11,[15][16][17][18][19][20][21][22][23][24][25]). Several causes have been given for the observed differences between hoop rupture strains and material ultimate tensile strains, including: (i) the quality of workmanship; (ii) overlaps of fiber sheets in the FRP shell; (iii) manufacturing imperfections (e.g., misalignment of fibers); (iv) shrinkage of the concrete (for FRP tube-encased concrete); (v) localized or non-uniform effects caused by imperfections in FRP shells and/or heterogeneity of cracked concrete; (vi) load eccentricities caused by specimen imperfections and/or test setup imprecisions; (vii) multiaxial stress condition generated on the FRP shell; and (viii) effect of the curvature of the FRP shell.…”

“…Average hoop rupture strain reduction factor (k ε ) with FRP type and confinement technique Table 4. Lam and Teng [3] Wu and Zhou [52] Wu and Wang [51] Al-Salloum and Siddiqui [45] Wei and Wu [50] Realfonzo and Napoli [7] Bisby et al [5] Jiang and Teng [32] AAE in predictions of strength enhancement ratio (f' cc /f' co ) Wei and Wu [50] Binici [46] Jiang and Teng [42] Youssef et al [53] Teng et al [49] Fahmy and Wu [47] Teng et al [48] De Lorenzis and Tepfers [4] AAE in predictions of strain enhancement ratio (ε cu /ε co ) …”

A Design-Oriented Combined Model (7 MPa to 190 MPa) for FRP-Confined Circular Short Columns

“…It was concluded that the strength models [2,[36][37][38] based on steel confinement give rise to higher estimation than experimental ones in each relevant strength range known in the current literature [1,5,33,73]. While the prediction performance of some models are restricted concerning range [22], some of those models are also capable of reasonably predicting wider data ranges [5,33,41].…”

“…The prediction capabilities of specific strain models [2,32,33,[38][39][40][41]43,44,46,73] are investigated. Following this assessment, the empirical models of this study are introduced to predict the ultimate strains (ε cu ) with high accuracy.…”