Experimental Study on Damage Identification of Nano-SiO₂ Concrete Filled GFRP Tube Column Using Piezoceramic...

This paper proposes a new approach to damage detection of nano-SiO₂ concrete-filled glass fiber reinforced polymer (GFRP) tube column using piezoceramic transducers. Stress waves are emitted and received by a pair of piezoceramic transducers embedded in the concrete-filled GFRP tube, and the energy and damage indices at different levels of loading in the tube are obtained by wavelet packet to evaluate the damage degree of GFRP tube nano-SiO₂ concrete column. Through the experimental studies, the effects of different nano-SiO₂ contents, concrete grades, and superplasticizer on the damage were analyzed to gain load-displacement curves, load-energy index curves, and load-damage index curves. The results show that the wave method can be adopted to monitor the damage of GFRP tube nano-SiO₂ concrete column. The specimens with 3% nano-SiO₂ content have the smallest energy change rate, indicating that adding 3% nano-SiO₂ content into concrete can effectively delay the development of damage. After the addition of superplasticizer, with the increase in the strength grade of concrete, the cracks in the specimen tend to develop slowly, and therefore the specimens have a stronger resistance to damage. The damage of the specimens with the nano-SiO₂ content of 1% appeared the latest, while the damage without the nano-SiO₂ specimen appeared the fastest. The experimental results show that this method can better monitor the damage of the Nano-SiO₂ concrete in the glass fiber reinforced polymer (GFRP) tube.