Effects of Aggregate Types on the Stress-Strain Behavior of Fiber Reinforced Polymer (FRP)-Confined Lightweight Concrete

Abstract

The realization of reducing concrete self-weight is mainly to replace ordinary aggregates with lightweight aggregates; such replacement usually comes with some intrinsic disadvantages in concrete, such as high brittleness and lower mechanical properties. However, these shortages can be effectively remedied by external confinement such as fiber reinforced polymer (FRP) jacketing. To accurately predict the stress-strain behavior of lightweight concrete with lateral confinement, it is necessary to properly understand the coupling effects that are caused by diverse aggregates types and confinement level. In this study, FRP-confined lightweight concrete cylinder with varying aggregate types were tested under axial compression. Strain gauges and linear variable displacement transducers were used for monitoring the lateral and axial deformation of specimens during the tests. By sensing the strain and deformation data for the specimens under the tri-axial loads, the results showed that the lateral to axial strain relation is highly related to the aggregate types and confinement level. In addition, when compared with FRP-confined normal weight aggregate concrete, the efficiency of FRP confinement for lightweight concrete is gradually reduced with the increase of external pressure. Replace ordinary fine aggregate by its lightweight counterparts can be significantly improved the deformation capacity of FRP-confined lightweight concrete, meanwhile does not lead to the reduction of compressive strength. Plus, this paper modified a well-established stress-strain model for an FRP-confined lightweight concrete column, involving the effect of aggregate types. More accurate expressions pertaining to the deformation capacity and the stress-strain relation were proposed with reasonable accuracy.

Experiment on Concrete with Partial Replacement of Sand with Alternate Green Materials

“…Pengda Li et al (2018), studied the stress strain behavior Fiber Reinforced Polymer (FRP)-confined light weight concrete with varying types of aggregates. Initially Zhou et al founded the stress strain behavior of carbon FRP confined light weight aggregate concrete where in only light weight coarse aggregates were adopted the self weight of concrete and reviled that ultimate strength and ductility capacity of LWAC could considerably enhanced by jacketing CFRP.…”

Ductility Evaluation of Damaged Recycled Aggregate Concrete Columns Repaired With Carbon Fiber-Reinforced Polymer and Large Rupture Strain FRP

“…This method can greatly increase the ultimate stress of concrete in confined systems and effectively make up for the internal defects of aggregates (Lam and Teng, 2003;Jiang and Wu, 2012;Nisticò and Monti, 2013;Song et al,. 2013;Li et al, 2018a;Rousakis, 2018;Li et al, 2019a;Zhou et al, 2019).…”

Flexure Performance of Externally Bonded CFRP Plates-Strengthened Reinforced Concrete Members

“…e main failure mode of CFRP-reinforced members is generally due to the stiffness characteristic concentration near the interface of CFRP and concrete. erefore, accurate prediction of postcracking stiffness is important for preventing the occurrence of debonding failure [18][19][20][21]. e test results show that CFRP-strengthened concrete structure can improve the strength and stiffness performance of the structure, and the lateral offset of CFRP from the longitudinal centerline has little effect on the flexural behavior of the concrete-CFRP interface [22].…”