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→Non-steel reinforcement: Bamboo Reinforced Concrete Tags: nowiki added Visual edit |
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===== '''i) ''Material Properties''''' =====
Flexural behavior of BRC in beam scenarios is continuously being researched. Current research conveys that under pure bending of a four-point bending test, bamboo reinforced concrete has similar or higher flexural properties than plain cement concrete (PCC) and steel reinforced cement concrete (RCC). Multiple designs of bamboo reinforced concrete have been tested and compared to traditional and steel reinforced concrete. Beams containing 2.8% and 3.8% bamboo reinforcement in respect to the beam’s cross section have been examined¹. Branching from the different percentages of reinforcement, testing conditions were changed to provide a total of eight combinations of different BRC. For each percent of bamboo reinforcement, the bamboo was either treated or untreated then left as its natural outer texture or engraved with a predetermined groove pattern. The bamboo was treated with a BondTite⁴ to create a waterproof surface and to create a bond layer between the concrete and bamboo. The groove pattern used for the grooved specimens, was grooves engraved around the thickness of the bamboo reinforcement with a 10-mm semicircle groove pattern¹. This groove pattern was determined by prior pull out tests of the bamboo used for reinforcement. For the concrete mix design of the beams, M20 grade concrete was used with an aggregate mixture of 70% - 20 mm and 30% - 10 mm aggregate¹. 30 total beams with dimensions of 140 mm x 150 mm x 1100 mm were tested under a 100 kN cavity flexural testing machine¹. The ultimate load, first crack load, average ductility, and maximum shear strength were all determined from the flexural testing performed on such beams and can be found in more detail in Section C.
In a separate study, the strength of the material was not the focus of the tensile testing, but rather the deflection. Nine beams were tested, three plain concrete (PC), three reinforced with steel (RC), and three reinforced with bamboo (BRC)². The samples were between 9 and 12 inches long and the concrete being used was Grade M20 with 28 day curing time. For the steel reinforced beam, Fe 250 grade bars were used. The BRC bars were treated with Sikadur 32 gel⁵ to improve the adhesion of the material. Using a 60-ton universal testing machine, a two point bending test was performed using a gradual loading rate of 1 mm/min². The maximum deflection was taken at midspan for each 75 mm x 150 mm cross section of the nine beams. ANN using MATLAB was used to then further analyze the load-displacement data. As background, ANN is an A.I. software that processes known parameters, called neurons, runs a specified function, in this case Levenberg-Marquardt algorithm and a nonlinear logistic-sigmoid transfer function, and provides an output for testing. The three input parameters for the ANN testing were load applied, tensile strength of reinforcement, and percentage of reinforcement. These values came directly from the experimental data. The desired output from the model was the predicted deflection of the member. Using the ANN analysis, 122 data points were provided, with 80% of the data selected randomly for training and the other 20% left out for testing. Five sample runs were performed in order to obtain the most accurate data. The results from this testing can be found in Section C below.
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