Experimental Study of Bond Stress between Concrete and FRP Rebars

2014 ◽  
Vol 488-489 ◽  
pp. 774-777 ◽  
Author(s):  
Nan Hui Yu ◽  
Ji Jun Fan

Owing to the excellent tensile strength and corrosion-resistance of fiber reinforced unsaturated polyester composite, it is expected to solve the corrosion problem of building instead of steel bars in some special occasions. Bonding performance between concrete and FRP rebars was studied by pull-out test,the influences of the surface form, anchorage length and diameter of FRP rebar on bonding strength were discussed in detail.

2010 ◽  
Vol 150-151 ◽  
pp. 460-463
Author(s):  
Fan Li ◽  
Ling Wang ◽  
Ming Jie Zhou ◽  
Xue Yong Wang

The bonding properties of post-installed bar in concrete are fundamental to evaluate the results of reinforced concrete. Including 102 specimen of post-installed bar and 18 specimen of embedded bar, 120 specimens were tested by pull-out test altogether. Comparative analysis considering diameter of steel bar, tensile strength of concrete, anchoring depth of steel bar, anchorage aperture are conducted. Based on the experimental results, it is shown that the bonding properties of post-installed bar are significantly influenced by steel bar, concrete tensile strength, installed depth bar and anchorage aperture. The ultimate average pullout forces of steels in specimen of post-installed bar and specimen of embedded bar are nearly equal. Three kinds of failure models are obtained. The experimental results can be useful for analyzing and evaluating bonding behaviors of post-installed bar in concrete.


2011 ◽  
Vol 471-472 ◽  
pp. 1034-1039 ◽  
Author(s):  
Zulkiflle Leman ◽  
S.M. Sapuan ◽  
S. Suppiah

Polymer composites using natural fibres as the reinforcing agents have found their use in many applications. However, they do suffer from a few limitations, due to the hydrophilicity of the natural fibres which results in low compatibility with the hydrophobic polymer matrices. This paper aims to determine the best sugar palm (Arenga pinnata) fibre surface treatment to improve the fibre-matrix interfacial adhesion. Fibre surface modifications were carried out by water retting process where the fibres were immersed in sea water, pond water and sewage water for the period of 30 days. The test samples were fabricated by placing a single fibre in an unsaturated polyester resin. Single-fibre pull-out tests showed that freshwater-treated fibres possessed the highest interfacial shear strength, followed by untreated fibres, sewage water-treated fibres, and sea water-treated fibres. Further surface analyses of the samples were performed using a Scanning Electron Microscope (SEM) and an Energy Dispersive X-ray Spectroscopy (EDS) system.


2016 ◽  
Vol 2016 ◽  
pp. 1-7 ◽  
Author(s):  
J. Sahari ◽  
M. A. Maleque

The mechanical properties of oil palm shell (OPS) composites were investigated with different volume fraction of OPS such as 0%, 10%, 20%, and 30% using unsaturated polyester (UPE) as a matrix. The results presented that the tensile strength and tensile modulus of the UPE/OPS composites increased as the OPS loading increased. The highest tensile modulus of UPE/OPS was obtained at 30 vol% of OPS with the value of 8.50 GPa. The tensile strength of the composites was 1.15, 1.17, and 1.18 times higher than the pure UPE matrix for 10, 20, and 30 vol% of OPS, respectively. The FTIR spectra showed the change of functional group of composites with different volume fractions of OPS. SEM analysis shows the filler pull-out present in the composites which proved the poor filler-matrix interfacial bonding.


2013 ◽  
Vol 465-466 ◽  
pp. 962-966 ◽  
Author(s):  
Mohd Pahmi bin Saiman ◽  
Mohd Saidin Bin Wahab ◽  
Mat Uzir Wahit

To produce a good quality of dry fabric for reinforced material in a natural-based polymer composite, yarn linear density should be in consideration. A woven kenaf dry fabric with three different linear densities of 276tex, 413.4tex and 759tex were produced. The fabrics with different linear densities were been optimize with the assistance of WiseTex software. The optimized dry fabrics were infused with unsaturated polyester to produce composite panel using vacuum infusion process. The composites properties were tested on the tensile strength, flexural strength and the impact strength. The result shows that the mechanical properties of the composite increased when the yarn linear densities increased.


2017 ◽  
Vol 10 (1) ◽  
pp. 122-140
Author(s):  
A. L. SARTORI ◽  
L. M. PINHEIRO ◽  
R. M. DA SILVA ◽  
S. B. FREITAS ◽  
T. G. CESAR

Abstract This paper describes the adherence behavior of a structural lightweight concrete with EPS beads (SLCEB) in a monotonic loading, based in a bibliographic review and in pull-out tests. The results of these SLCEB tests were compared with those of an ordinary concrete (OC) and with the values based in indications of the Brazilian code ABNT NBR 6118:2014 - Design of concrete structures. The pull-out tests of two batches of SLCEB and one of OC were analyzed, in a total of 60 tests. Mechanical characteristics were determined too, such as: compressive strength and tensile strength in split cylinder test. The calculated results according to the above mentioned standard were very different from those obtained in the tests, indicating that the theoretical values are more conservative than the experimental ones. It was also verified that it is possible to use SLCEB in structures with respect to the adequate adherence of reinforcement in the concrete.


2013 ◽  
Vol 477-478 ◽  
pp. 697-700
Author(s):  
Yan Zheng ◽  
Hong Zhen Kang ◽  
Guang Qi Wang

For application of FMT (ferrous mill tailing) to structural concrete, it is urgent need to study the bond behavior of reinforced bars with FMT concrete. In this paper, 72 pull-out tests of HRB335 steel bars from FMT concrete were carried out. The test phenomena and various factors influence on bond behavior were obtained. The results show that the bonding performance between deformed bars and FMT concrete is approximate to that of deformed bars and ordinary concrete. The results should provide technical support for application of FMT concrete in building structures.


2016 ◽  
Vol 711 ◽  
pp. 673-680 ◽  
Author(s):  
Zhiwen Ye ◽  
Wei Ping Zhang ◽  
You Hu ◽  
Xiang Lin Gu

This paper presents an experimental investigation on the influence of fatigue loading history on bond behavior between steel bars and concrete. Reinforced concrete specimens were subjected to fatigue loadings with different amplitudes and cycles before undergoing eccentric pull-out tests. Tests revealed that all specimens failed with the splitting of the concrete cover. With increased loading cycles, the concrete in front of transverse ribs usually becomes denser at the beginning. Meanwhile, the initial bond stiffness and the bond strength increased, while the slip corresponding to the peak bond stress decreases. With the further increase of loading cycles, the bond strength begins to decrease after it reaches a critical value. This study determined that for specimens subjected to repeated loading with a larger amplitude, fewer cycles are needed for the bond strength to go up to the critical bond strength.


2010 ◽  
Vol 24 (23) ◽  
pp. 4459-4470 ◽  
Author(s):  
B. F. YOUSIF

The effect of two types of oil palm fibres (bunch and fruit) on mechanical properties of polyester composites is examined in the current work considering different volume fractions. Tensile, compression, and flexural properties of the composites were investigated. In addition to that, tensile strengths were calculated theoretically using Hirsch model. Scanning electron microscope (SEM) was used to observe the fracture mechanism of the specimens. Single fibre pull-out tests were performed to determine the interfacial shear strength between polyester resin and both types of oil palm fibres. Results revealed that both types of oil palm fibres enhanced the mechanical performance of polyester composites. At a higher volume fraction (40–50%), tensile strength of the polyester composite was improved, i.e., 2.5 times improvement in the tensile strength value. Experimental tensile strength values of oil palm bunch/polyester composites have a good correlation with the theoretical results, especially at low volume fractions of fibre. Flexural strength of polyester worsened with oil palm fibres at all volume fractions of fibre.


The present study narrates about the performance of bamboo fiber against polymer matrix. Among different natural fibers bamboo proved to be a potential ones for effective composite production. Based on this aspect this research carried out by using bamboo fiber of length 5mm in chopped form as reinforcement unsaturated polyester used as matrix. The studies were done by varying the bamboo fiber weight percentage as 20, 30 and 40% weight respectively. The prepared specimens are subjected to tensile strength, flexural strength and Impact strength studies. Based on the results obtained this composite suggested for suitable application.


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