Harnessing Limestone powder to enhance the thermal crack resistance of manufactured sand

Manufactured sand concrete (MSC) has increasingly applied in engineering. However, how to enhance the thermal crack resistance of MSC has not clearly studied yet, which limits the wide applications of manufactured sand in engineering. We have adopted the method of mixing limestone powder (LP) to make MSC with four mass fractions (wt.%) of 5%, 10%, 15%, and 20% of LP content, designed the mix proportion of concrete, tested their mechanical properties, observed their microstructure by scanning electron microscopy (SEM) and investigated the effect of LP on anti-cracking performance using temperature stress testing machine (TSTM). These findings reveal that the mechanical properties and thermal crack resistance of 15% LP MSC are the best. Our results also provide a research basis for the MSC to be widely used in engineering.