An-Najah University Journal for Research - A (Natural Sciences)

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Keywords

• Self-compacting concrete
• EPS.
• Flexural behavior
• GFRP
• Recycled PET fibers

Abstract

This study aims to develop a modified self-compacting concrete incorporating expanded polystyrene (EPS) beads and recycled polyethylene terephthalate (PET) fibers to reduce density, improve ductility, and minimize environmental impact. Experimental work consists of five concrete beams of 150×200×1500 mm that have been designed and tested for studying the flexural behavior of steel and GFRP rebars of concrete beams under a three-point load setup. Adding a high content of cement and silica fume (SF) enhanced the flowability, also preventing the floating of EPS during mixing. This study focused on the impact of EPS and PET fiber. The results showed that partial replacement of the coarse aggregate with 0.17% EPS reduced the density and load capacity by 13.5% and 35.2%, respectively. In contrast, their ductility has been improved by 27.2%. The deflection has been reduced by 6% compared to the specimen without fiber, and the load capacity has improved by 15.6%. The steel reinforcement beam demonstrated different behavior with observed yielding, unlike the GFRP beam, which showed a higher load capacity, 42.4% more than the steel beam. Increasing the reinforcement ratio of GFRP raised the ultimate load capacity by 13.5% and decreased the deflection, strain, and ductility by 15%, 43%, and 13%, respectively. All GFRP beams showed a compression failure mode; in contrast, the steel beam showed a tension failure before the concrete crash. Comparing the test results with theoretical values of current commonly used specifications, it was found that the code predicts a more conservative moment capacity.

معلومات المقال

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الكلمات الإفتتاحية

• Self-compacting concrete
• EPS.
• Flexural behavior
• GFRP
• Recycled PET fibers

الملخص

This study aims to develop a modified self-compacting concrete incorporating expanded polystyrene (EPS) beads and recycled polyethylene terephthalate (PET) fibers to reduce density, improve ductility, and minimize environmental impact. Experimental work consists of five concrete beams of 150×200×1500 mm that have been designed and tested for studying the flexural behavior of steel and GFRP rebars of concrete beams under a three-point load setup. Adding a high content of cement and silica fume (SF) enhanced the flowability, also preventing the floating of EPS during mixing. This study focused on the impact of EPS and PET fiber. The results showed that partial replacement of the coarse aggregate with 0.17% EPS reduced the density and load capacity by 13.5% and 35.2%, respectively. In contrast, their ductility has been improved by 27.2%. The deflection has been reduced by 6% compared to the specimen without fiber, and the load capacity has improved by 15.6%. The steel reinforcement beam demonstrated different behavior with observed yielding, unlike the GFRP beam, which showed a higher load capacity, 42.4% more than the steel beam. Increasing the reinforcement ratio of GFRP raised the ultimate load capacity by 13.5% and decreased the deflection, strain, and ductility by 15%, 43%, and 13%, respectively. All GFRP beams showed a compression failure mode; in contrast, the steel beam showed a tension failure before the concrete crash. Comparing the test results with theoretical values of current commonly used specifications, it was found that the code predicts a more conservative moment capacity.