Confining Concrete Column with Eco-friendly UHPC

Presented By: Alessandro Fantilli Affiliation: Polytechnic University of Turin Description: UHPC shows excellent mechanical performances and has been successfully used for repairing, strengthening, and seismic retrofitting of old structures. However, UHPC is not always an environmentally friendly product, due to the large quantity of cement contained in the mixture. Thus, different rates of fly ash substitute herein part of the cement, and new UHPCs are used to retrofit concrete columns. Specifically, to simulate the mechanical response of confined columns, cylindrical specimens, made of normal concrete and reinforced with different UHPC jackets, are tested in uniaxial compression. Relationships between the size of the jacket, the percentage of cement replaced by fly ash, and the strength of the columns are measured and analyzed by means of the eco-mechanical approach. As a result, a replacement of approximately 50% of cement with fly ash, and a suitable thickness of the UHPC jacket, might ensure the lowest environmental impact without compromising the mechanical performances.