A method for treating recycled concrete aggregate strengthened by volcanic ash

Abstract

The invention relates to a treatment method of volcanic-ash-paste-reinforced recycled concrete aggregate. The method comprises the following steps: (1) carrying out crushing treatment and screening on recycled concrete, and drying to obtain recycled aggregate; (2) adding water into a volcanic ash material with the particle size of less than 60 micrometers to prepare a volcanic ash paste, and carrying out ultrasonic dispersion to form a homogeneous paste solution; (3) immersing the dried recycled aggregate in the step (1) in the homogeneous paste solution prepared in the step (2), and stirring; (4) screening the mixture treated in the step (3) to remove the recycled aggregate, and filtering to remove the excessive paste solution; (5) drying the screened recycled aggregate, and carrying out kneading dispersion on the agglomerate aggregate; and (6) screening the recycled aggregate treated in the step (5) to obtain the volcanic-ash-paste-reinforced recycled concrete aggregate. Compared with the mortar prepared from the untreated recycled concrete aggregate, the 3-day compression strength and 28-day compression strength of the mortar prepared from the volcanic-ash-paste-reinforced recycled concrete aggregate are enhanced by 17% or above, the chlorine ion permeability coefficient is lowered by 30% or above, and the new / old interface microhardness of the mortar is enhanced by 30% or above.

Description

technical field

[0001] The invention relates to a method for strengthening treatment of recycled concrete aggregates, in particular to a method for strengthening treatment of recycled concrete aggregates with volcanic ash. Background technique

[0002] Regenerated aggregate is the aggregate obtained after crushing waste concrete. Compared with natural aggregate, the surface of recycled aggregate has hardened cement slurry attached. The presence of hardened cement paste results in high water absorption and low strength of recycled aggregates. This results in a greater reduction in the performance of recycled concrete compared with ordinary concrete. By strengthening the recycled aggregate, the physical and mechanical properties of the recycled aggregate can be improved, thereby improving the performance of the recycled concrete. The improvement of the performance of recycled concrete is of great significance to the recycling and sustainable development of concrete. [0003...

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