Long-Term Mechanical Properties, Drying Shrinkage, and Creep Behaviour of Manufactured-Sand Concrete in Plateau Regions: 1-Year Measurements and Analysis.

Infrastructure construction in plateau areas not only needs to take into account the impact of harsh climatic conditions, but also faces the problem of raw material shortage. Herein, this work investigates the long-term mechanical properties, drying shrinkage, and creep behaviour of manufactured-sand concrete in plateau regions via 1-year measurements. Results show that the plateau harsh environment coarsens the pore structure of manufactured-sand concrete, leading to the 365-day compressive strength and elastic modulus dropping by at most 10.2% and 5.3%, respectively, while the 365-day drying shrinkage and specific creep increased by at most 15.3% and 9.4%, respectively. Meanwhile, with the synergistic effect of silica fume, calcium sulfate whiskers and shrinkage-reducing agent, the 365-day compressive strength increased by 12.3%, and drying shrinkage and specific creep were reduced by 10.5% and 16.6%, respectively, resulting from its dense microstructure effect. Overall, this work offers guidance for preparing high-performance concrete in plateau areas, promotes the resource utilisation of manufactured sand, and has significant implications for enhancing the service life of concrete while reducing construction costs.