Noor Azlina Abdul Hamid

Strain Distribution on Reinforcement of Concrete Beams Reinforced with Glass Fiber Reinforced Polymer (GFRP) Bars

This paper presents a part of the results from an experimental study of strain distribution on reinforcement of concrete beams reinforced with glass fiber-reinforced polymer (GFRP) bars. Under static loading conditions, eight concrete beams reinforced with GFRP bars were tested and as comparison eight beams with steel reinforcement were also tested. All of the beams were prepared with varying ratios of longitudinal reinforcement bars and stirrups. The effect of shear span-effective depth ratio on strain distribution of longitudinal reinforcement was also observed. Furthermore, the behavior of strain on stirrups due to different materials of longitudinal reinforcement was also discussed in this report. The test results show that the ratio of longitudinal reinforcement significantly influence the strain distributions on reinforcement where the beams with higher ratio exhibit higher strain. Moreover, it was also obtained that the different types of longitudinal reinforcement considerably influences the strain behavior on stirrups as higher strain was observed in beams reinforced with GFRP bars.

Shear Capacity of Non-Metallic (FRP) Reinforced Concrete Beams with Stirrups

This study presents test results of simply supported concrete beams longitudinally reinforced either by steel or glass fiber-reinforced polymer (GFRP). A total of sixteen large-scale concrete beams with steel stirrups were constructed and tested under four-point monotonic loading until failure. Half of the beams were longitudinally reinforced with GFRP bars, while the other half was reinforced with conventional steel bars as control specimens. To examine the shear behavior of the GFRP reinforced concrete (RC) beams, the main parameters investigated in the study included shear span-effective depth ratios, longitudinal reinforcement ratios and stirrup ratios. Two modes of failure, namely flexure and shear were observed. Due to low modulus elasticity of FRP bars, it was found that lesser shear strength resulted in concrete beams reinforced with GFRP bars compared to beams reinforced with steel bars. Moreover, the influence of the shear span-effective depth ratios and longitudinal reinforcement ratios significantly affect the distribution of internal forces in GFRP reinforced concrete beams. The test results correlated well with the prediction values provided by standard codes and design guidelines except in the case of GFRP reinforced concrete beams failed on shear.

Compressive strength, flexural strength and water absorption of concrete containing palm oil kernel shell

Effect of inclusion of palm oil kernel shell (PKS) and palm oil fibre (POF) in concrete was investigated on the compressive strength and flexural strength. In addition, investigation of palm oil kernel shell on concrete water absorption was also conducted. Total of 48 concrete cubes and 24 concrete prisms with the size of 100mm x 100mm x 100mm and 100mm x 100mm x 500mm were prepared, respectively. Four (4) series of concrete mix consists of coarse aggregate was replaced by 0%, 25%, 50% and 75% palm kernel shell and each series were divided into two (2) main group. The first group is without POF, while the second group was mixed with the 5cm length of 0.25% of the POF volume fraction. All specimen were tested after 7 and 28 days of water curing for a compression test, and flexural test at 28 days of curing period. Water absorption test was conducted on concrete cube age 28 days. The results showed that the replacement of PKS achieves lower compressive and flexural strength in comparison with conventional concrete. However, the 25% replacement of PKS concrete showed acceptable compressive strength which within the range of requirement for structural concrete. Meanwhile, the POF which should act as matrix reinforcement showed no enhancement in flexural strength due to the balling effect in concrete. As expected, water absorption was increasing with the increasing of PKS in the concrete cause by the porous characteristics of PKS

Finite element modelling of concrete beams reinforced with hybrid fiber reinforced bars

Concrete is a heterogeneous composite material made up of cement, sand, coarse aggregate and water mixed in a desired proportion to obtain the required strength. Plain concrete does not with stand tension as compared to compression. In order to compensate this drawback steel reinforcement are provided in concrete. Now a day, for improving the properties of concrete and also to take up tension combination of steel and glass fibre-reinforced polymer (GFRP) bars promises favourable strength, serviceability, and durability. To verify its promise and support design concrete structures with hybrid type of reinforcement, this study have investigated the load-deflection behaviour of concrete beams reinforced with hybrid GFRP and steel bars by using ATENA software. Fourteen beams, including six control beams reinforced with only steel or only GFRP bars, were analysed. The ratio and the ordinate of GFRP to steel were the main parameters investigated. The behaviour of these beams was investigated via the load-deflection characteristics, cracking behaviour and mode of failure. Hybrid GFRP-Steel reinforced concrete beam showed the improvement in both ultimate capacity and deflection concomitant to the steel reinforced concrete beam. On the other hand, finite element (FE) modelling which is ATENA were validated with previous experiment and promising the good result to be used for further analyses and development in the field of present study.