Reinforced concrete (RC) deep beams strengthened with Chopped Glass Strand Mat (CGSM) Composites ... more Reinforced concrete (RC) deep beams strengthened with Chopped Glass Strand Mat (CGSM) Composites often fail by de-bonding in one of several possible modes. This paper presents an experimental study on CGSM composite de-bonding failure in RC deep beams. The basic objective of this study was to develop a better understanding of the behavior and failure mechanisms of CGSM strengthened RC deep beams. The results of six beams tested under three-point bending are presented and discussed in detail. Two of them were un-strengthened and served as reference specimens. Four RC deep beams were strengthened with CGSM using epoxy resin. The CGSM was applied in two orientations; i.e., two-sided and three-sided. Two CGSM strengthened RC deep beams were tested without any anchorages to investigate the de-bonding failure mechanism. While remaining CGSM strengthened beams were anchored with mechanical anchors to improve the bond strength between concrete and surface. De-bonding failure CGSM was observed in both beams (i.e. CGSM strengthened RC deep beams without anchorage). Whereas no de-bonding of CGSM composite where observed in mechanical anchored RC deep beams.
This paper examines the effect of glass chopped strand mat fiber composites (GCSM) with the mecha... more This paper examines the effect of glass chopped strand mat fiber composites (GCSM) with the mechanical anchor on the shear strength of reinforced concrete deep beams. Two types of matrix system were used to provide stresses between the fibers and also between the fiber composites-to-concrete interface. Epoxy and polyester resin were investigated and compared to find the suitable resin matrix. Mechanical expansion anchor system which was recently proposed by the author was used in this study. The experimental results indicated that using GCSM composites with mechanical anchors led to enhancement of load-carrying capacity and stiffness of the beams. Epoxy resin system was found to be more effective compared to Polyester resin. The ultimate shear capacity of the RC deep beams strengthened with epoxy system was increased up to 68% compared to the control specimen. Continuously wrapped the GCSM fiber composites over the bottom and both sides of the beam in the form of a U-wrapped provided additional anchorage at the bottom end of fiber composites. This leads to the prevention of debonding and the increase of loading capacity. Providing additional bond strength of the bond interface by using mechanical anchor found to be more effective since it leads to more usage of the composites. Strengthening technique using FRP wrapped with mechanical anchors supposedly confined the compressive strut which is able to increase the loading capacity.
The strengthening of existing reinforced concrete structures is required due to substantial incre... more The strengthening of existing reinforced concrete structures is required due to substantial increment in service and live loads or due to the severe environmental deterioration. Fiber Reinforced Polymer (FRP) has been a popular material for strengthening technique due to its high strength, ease of use and lightweight. The current paper presents an experimental investigation of shear strengthening of RC deep beams with glass chopped strand mat (GCSM). Six rectangular deep beams were constructed and tested in the same manner. One beam was used as a control specimen and the remaining five were strengthened with different layers and wrapping schemes. The experimental results show that externally bonded GCSM is effective to increase the shear strength of RC deep beams. Its contribution depends on the thickness and bonded configurations of fiber composites. An increasing number of GCSM layers leads to increase the shear strength of RC deep beams. U-wrapped bonded GCSM strengthening is more effective compared to two-sided bonded.
Reinforced concrete (RC) deep beams strengthened with Chopped Glass Strand Mat (CGSM) Composites ... more Reinforced concrete (RC) deep beams strengthened with Chopped Glass Strand Mat (CGSM) Composites often fail by de-bonding in one of several possible modes. This paper presents an experimental study on CGSM composite de-bonding failure in RC deep beams. The basic objective of this study was to develop a better understanding of the behavior and failure mechanisms of CGSM strengthened RC deep beams. The results of six beams tested under three-point bending are presented and discussed in detail. Two of them were un-strengthened and served as reference specimens. Four RC deep beams were strengthened with CGSM using epoxy resin. The CGSM was applied in two orientations; i.e., two-sided and three-sided. Two CGSM strengthened RC deep beams were tested without any anchorages to investigate the de-bonding failure mechanism. While remaining CGSM strengthened beams were anchored with mechanical anchors to improve the bond strength between concrete and surface. De-bonding failure CGSM was observed in both beams (i.e. CGSM strengthened RC deep beams without anchorage). Whereas no de-bonding of CGSM composite where observed in mechanical anchored RC deep beams.
This paper examines the effect of glass chopped strand mat fiber composites (GCSM) with the mecha... more This paper examines the effect of glass chopped strand mat fiber composites (GCSM) with the mechanical anchor on the shear strength of reinforced concrete deep beams. Two types of matrix system were used to provide stresses between the fibers and also between the fiber composites-to-concrete interface. Epoxy and polyester resin were investigated and compared to find the suitable resin matrix. Mechanical expansion anchor system which was recently proposed by the author was used in this study. The experimental results indicated that using GCSM composites with mechanical anchors led to enhancement of load-carrying capacity and stiffness of the beams. Epoxy resin system was found to be more effective compared to Polyester resin. The ultimate shear capacity of the RC deep beams strengthened with epoxy system was increased up to 68% compared to the control specimen. Continuously wrapped the GCSM fiber composites over the bottom and both sides of the beam in the form of a U-wrapped provided additional anchorage at the bottom end of fiber composites. This leads to the prevention of debonding and the increase of loading capacity. Providing additional bond strength of the bond interface by using mechanical anchor found to be more effective since it leads to more usage of the composites. Strengthening technique using FRP wrapped with mechanical anchors supposedly confined the compressive strut which is able to increase the loading capacity.
The strengthening of existing reinforced concrete structures is required due to substantial incre... more The strengthening of existing reinforced concrete structures is required due to substantial increment in service and live loads or due to the severe environmental deterioration. Fiber Reinforced Polymer (FRP) has been a popular material for strengthening technique due to its high strength, ease of use and lightweight. The current paper presents an experimental investigation of shear strengthening of RC deep beams with glass chopped strand mat (GCSM). Six rectangular deep beams were constructed and tested in the same manner. One beam was used as a control specimen and the remaining five were strengthened with different layers and wrapping schemes. The experimental results show that externally bonded GCSM is effective to increase the shear strength of RC deep beams. Its contribution depends on the thickness and bonded configurations of fiber composites. An increasing number of GCSM layers leads to increase the shear strength of RC deep beams. U-wrapped bonded GCSM strengthening is more effective compared to two-sided bonded.
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Papers by Lalin Lam
loads or due to the severe environmental deterioration. Fiber Reinforced Polymer (FRP) has been a popular material for
strengthening technique due to its high strength, ease of use and lightweight. The current paper presents an experimental
investigation of shear strengthening of RC deep beams with glass chopped strand mat (GCSM). Six rectangular deep
beams were constructed and tested in the same manner. One beam was used as a control specimen and the remaining
five were strengthened with different layers and wrapping schemes. The experimental results show that externally bonded
GCSM is effective to increase the shear strength of RC deep beams. Its contribution depends on the thickness and bonded
configurations of fiber composites. An increasing number of GCSM layers leads to increase the shear strength of RC deep
beams. U-wrapped bonded GCSM strengthening is more effective compared to two-sided bonded.
loads or due to the severe environmental deterioration. Fiber Reinforced Polymer (FRP) has been a popular material for
strengthening technique due to its high strength, ease of use and lightweight. The current paper presents an experimental
investigation of shear strengthening of RC deep beams with glass chopped strand mat (GCSM). Six rectangular deep
beams were constructed and tested in the same manner. One beam was used as a control specimen and the remaining
five were strengthened with different layers and wrapping schemes. The experimental results show that externally bonded
GCSM is effective to increase the shear strength of RC deep beams. Its contribution depends on the thickness and bonded
configurations of fiber composites. An increasing number of GCSM layers leads to increase the shear strength of RC deep
beams. U-wrapped bonded GCSM strengthening is more effective compared to two-sided bonded.