Activity of calcined coal gangue fine aggregate and its effect on the mechanical behavior of cement mortar

• Aggregate the dissolubility ion and its surface area ratio as an index of activity.
• Analyzed under different calcination temperature fine aggregate XRD patterns.
• Influence of different active aggregate of mortar strength through microscopic test.
• Effect of different coal gangue fine aggregate activity on mortar strength.

In order to reveal the influence of coal gangue aggregate activity on the mechanical properties of the mortar, to promote coal gangue fine aggregate in concrete mortar application, this paper in view of the calcined coal gangue aggregate carried out ion dissolution test (ICP), construction of the coal gangue aggregate ion dissolution amount and its surface area ratio as a quantitative index of activity, namely activity index of Ka. The different fineness modulus, different curing age of concrete mortar carried out compressive strength and flexural strength test, and the hardening of cement mortar combined with microscopic test results, in order to analyze the influence of coal gangue aggregate activity on the mechanical performances of mortar. Experimental results show that, under the same calcination temperature and surface area of coal gangue fine aggregate with the same ion dissolution ability, coal gangue fine aggregate index activity increases with the gradual decrease of fineness modulus. A higher activity index of coal gangue fine aggregate mortar corresponds to higher compressive strength and flexural strength of mortar in the improved macro mechanical properties; the early strength of mortar has clear characteristics.