Method for testing alkali efflorescence resistance of pavement brick

Abstract

The invention discloses a method for testing the alkali efflorescence resistance of a pavement brick. The method comprises the following steps of: (1) selecting an experimental pavement brick test piece; (2) saturating the test piece by water absorption; (3) laying 10 mm thick sand having a moisture content of 24% in a plastic box, then placing the water-absorbing saturated test piece on the sandwith a surface layer facing upward; (4) adopting a high and low temperature circulation system, setting a high temperature environment of 25 to 30 DEG C, a low temperature environment of 0 to 5 DEG C,24 hours of a cycle period, a high temperature period of 6+ / -1 hours, a low temperature period of 18+ / -1 hours; placing the plastic box containing the water-absorbing saturated test piece and the sand in the low temperature environment to cool it to form a supersaturated state of a solution; then placing the box in the high temperature environment and carrying out a blowing treatment to promote the evaporation of water to precipitate crystals; and (5) obtaining a efflorescence condition on the surface of the pavement brick test piece after 5 to 7 cycles.

Description

technical field [0001] The invention belongs to the technical fields of building materials and civil engineering, and in particular relates to a method for testing the pan-alkali resistance of pavement bricks. Background technique [0002] During the use of pavement bricks, the phenomenon of "pan-alkali" often occurs, especially in northern my country. The efflorescence problem will not only affect the appearance and image of pavement bricks, affect the on-time delivery and acceptance of the project, but also affect the strength and durability of pavement bricks in severe cases. At present, there is still a lack of methods that can completely solve the efflorescence of pavement bricks, and it is of great value to study the suppression measures of efflorescence of pavement bricks. [0003] However, there is currently no feasible method for testing the pan-alkali resistance of pavement bricks. There are some methods such as the "spraying and drying method" in the "Wall Finish...

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Problems solved by technology

[0003] However, there is currently no feasible method for testing the pan-alkali resistance of pavement bricks. There are some methods such as the "spraying and drying method" in the "Wall Finishing Mortar" specification, as well as the double-chamber climate box method, water immersion method, and dripping water method. There are different degrees of problems in the method, such as uneven efflorescence, uncontrollable efflorescence conditions, and inconspicuous efflorescence phenomenon, etc., which are not suitable for the research on the anti-efflorescence performance of pavement bricks with relatively large porosity.