Thermomechanical properties of a new small-scale reinforced concrete thermo-active pile for centrifuge testing

摘要

The use of thermo-active geo-structures has been recognised to be a sustainable engineeringrnsolution that can reduce carbon emissions from civil infrastructure. Physical modelling in a geotechnical centrifugernhas been increasingly used to study the behaviour of this kind of geo-structures and their interactionrnwith the surrounding soil under cyclic heating/cooling loads. Previous studies have been limited by the choicernof materials used to model thermo-active geo-structures (such as aluminium and conventional concrete), duernto inaccurate scaling of the thermal properties and the inability to capture the quasi-brittleness and strengthrnproperties of reinforced concrete (RC) due to improper scaling of aggregate sizes. The paper aims to develop arnnew thermally-enhanced plaster-based model concrete which can realistically reproduce both the thermal andrnmechanical properties that are representative of concrete at prototype scale. The new model concrete, combinedrnwith steel wire reinforcement (i.e. geometrically scaled reinforcing bars and stirrups), was then used to creatern1:20 scaled RC thermo-active piles. Effects of temperature on their thermomechanical behaviour, including therncoefficient of thermal expansion, moment capacity and flexural stiffness, were investigated. The suitability ofrnusing the newly-developed RC thermo-active piles for future centrifuge testing is discussed.