The surface layer of cement plastic stone rockery is mainly made of cement mortar, including artificial stone like crack and crack tortoise crack caused by special cement mortar. Tortoise crack is naturally formed, which has a great relationship with cement. Turtle cracks not only affect the beauty of rockery, but also have a great impact on the service life of plastic rock rockery.
How do turtle cracks occur? The cement mortar in the rockery production needs a relatively heavy proportion of cement, which is the requirement of the technology, convenient for the plastic surface of the construction personnel, and also convenient for the later texture description. The aggravation of cement proportion, on the one hand, reduces the water proportion, on the other hand, intensifies the reaction of cement, and cracks appear in the initial setting process of mortar. The density of mortar surface is not high, and the weight of mortar increases, which also leads to turtle cracks.
What are the consequences of turtle cracks? On the one hand, tortoise cracks affect the surface effect of the rockery; on the other hand, tortoise cracks on the surface of the plastic rock rockery will lead to the entry of water vapor, which will react with the steel structure and aggravate the corrosion of the steel structure; the corrosion expansion of the steel structure will also aggravate the increase of tortoise cracks, and finally more water vapor will enter the rockery, which may lead to the fall off of the surface layer and the final impact Service life of plastic rock rockery.
1、 Shotcreting Technology, Shotcreting Technology is to spray cement mortar on the surface of plastic rock rockery by means of shotcreting machine. Compared with manual plastering (mortar), the mortar has high compactness and strong structural force. As required by the secondary shotcreting, the joint shall be scratched to increase the overall thickness of the mortar.
2、 With the addition of composite materials, the viscosity and water retention of mortar are increased, and the reaction time of cement is prolonged. Common additives are: dispersible rubber powder, cellulose, fiber, etc. The proportion and time of addition should be determined according to the season and dosage experiment.
At present, the carving mortar appearing in the market is to add a variety of composite materials to the ready mixed cement mortar, so as to increase the special type of cement mortar.
3、 Maintenance: after the mortar surface of rockery is made, water maintenance shall be carried out 12 hours later. The maintenance interval is 4 hours. 48 hours after the surface is made is the main maintenance period. Water maintenance can increase the hardness of mortar and prevent the occurrence and increase of turtle cracks.