Research on frost resistance of desert sand and sandy sand concrete and lifetime prediction

• Different admixtures of desert sand are used to replace the natural river sand. • The mechanism of Tengger desert sand and Maowusu sand on the durability of concrete is revealed. • The optimal admixture of desert sand for desert sand concrete is obtained under cold and arid environments. • Desert sand, as extra fine sand, can improve the durability of concrete. • Provides a theoretical reference for the design of low-carbon sustainable concrete The swift advancement of global infrastructure has significantly heightened the need for concrete materials recently, resulting in critical issues such as carbon emissions and energy usage. To mitigate the issues of the construction industry, it is essential to select sustainable and low-carbon building materials by examining a diverse array of choices. This study employed Tengger Desert Sand (TDS) and Maowusu Sand (MSS) from western China as experimental materials, with substitution rates of 0%, 15%, 30%, and 45%, to examine the durability performance disparities between Desert Sand Concrete (DSC) and Sandy Sand Concrete (SSC) under freeze-thaw cycles, considering the distinct environmental conditions of alpine regions. The durability degradation and microstructural alterations of concrete were examined using indicators such as compressive strength, mass loss rate, and dynamic elastic modulus during freeze-thaw cycles, alongside methodologies including nuclear magnetic resonance (NMR) and scanning electron microscopy (SEM). These methodologies were utilized to elucidate the temporal performance characteristics of concrete. A life prediction model was developed based on Weibull distribution theory to evaluate the durability lifespan of concrete in alpine conditions. The findings indicate that DSC outperforms SSC at an equivalent substitution rate. Subsequently, during 200 freeze-thaw cycles, at a TDS substitution rate of 45%, the concrete demonstrates superior durability and frost resistance, characterized by a mass loss rate of 0.19%, an 8.06% decrease in relative dynamic elastic modulus, and a 28-day compressive strength of 40.13 MPa. As the admixture increased, the extent of damage in the concrete sample exhibited a consistent decline. The extent of damage in the freeze-thaw environment is ranked as follows: MSS45 > DS0 > MSS15 > TDS15 > MSS30 > TDS30 > TDS45. The Weibull life prediction model forecasts that TDS45 has the maximum longevity at 104 years, while MSS45 has the shortest lifespan at 53 years. This study employs experimental research to examine how desert sand (DS) and sandy sand (SS) affect the durability of concrete, thereby tackling the scarcity of natural river sand resources, fostering sustainable and low-carbon development in the construction sector, and offering technical assistance for its use in infrastructure projects in alpine areas.