Influence of Flake Particles in Manufactured Sand on the Performance of Cement Mortar and Concrete

The performance of manufactured sand cement mortar and concrete containing flake particles of varying size and content was tested in this study. The influence law and the size and content of flake particles on the performance of mortar and concrete were analysed through the grey relational theory, the mechanism influence was revealed through the MIP and SEM tests. The test data reveal that the voidage of the manufactured sand increases with the size or content of flake particles, decreasing the fluidity, strength, and impermeability of mortar and concrete. MIP test shows that the increase in flake particles size or content in manufactured sand will lead to the increase in the proportion of large harmful pores in the mix system, which is the main reason for the decrease in its strength and impermeability. Furthermore, the grey correlation analysis shows that the total content of flake particles and the 4.75–9.5 mm of flake particles in manufactured sand are the two main factors that reduce the performance of mortar and concrete, and they should be strictly controlled. It is feasible and necessary to use “the method of bar sieve detection” and “the limit of flake particles content” as the evaluation index of manufactured sand, which is beneficial to promote the efficient and safe application of manufactured sand in concrete industry.