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What is the practice of permeable concrete?
Permeable concrete building is made of high-grade cement, 6mm pebbles and some additives in a certain proportion. Concrete construction steps of pervious concrete:

Mixing: the consistency of cement slurry in the mixture of permeable floor is relatively large and the quantity is relatively small. In order to ensure that the cement slurry can be evenly wrapped on the orthopedics, a forced mixer should be used, and the mixing time should be more than 5 minutes.

Pouring: Before pouring, the subgrade must be wetted with water. Otherwise, the rapid water loss of the permeable floor will weaken the bond strength between aggregates. Because the mixture of permeable ground is relatively dry and hard, it is possible to mix permeable ground and good permeable ground materials on the subgrade.

Vibrating: It is not advisable to vibrate or tamp strongly during pouring. Generally, flat vibrator is used to lightly vibrate the paved permeable concrete mixture, but it must be noted that high-frequency vibrator cannot be used, otherwise the concrete will be too dense, the porosity will be reduced and the permeable effect will be affected. At the same time, the high-frequency vibrator will separate the cement paste from the surface of coarse aggregate and flow into the bottom to form an impermeable layer, which will make the material lose its water permeability.

Rolling: After vibrating, the permeable concrete mixture shall be further compacted and leveled with solid steel pipe or light roller. Considering the consistency of the mixture and the surrounding temperature, it may be necessary to roll it several times, but it should be noted that the roller must be cleaned before rolling to prevent the aggregate from sticking.

Maintenance: Because there are many holes in the permeable ground, it is easy to lose water and dry quickly, so maintenance is very important. Especially in early maintenance, attention should be paid to avoid a large amount of evaporation of water in the floor. Usually, the time of formwork removal of permeable concrete is shorter than that of ordinary concrete, so its sides and edges will be exposed to the air. Cover the pavement and side surface with plastic film or striped cloth in time to ensure the humidity and full hydration of cement. Watering and curing of the permeable ground should be started 1 day after pouring. It is not suitable to spray water with pressure water column on the concrete surface, which will take away some cement slurry and cause some weak parts, but it can be watered directly from top to bottom under normal circumstances. Watering and curing time of permeable ground shall be no less than 7 days.