Mosaic is a kind of building decoration material. Because of its small particles, flexible color matching, and easier arrangement of patterns, it was used in the decoration of indoor steps, platforms, and toilets by European ingenuity designers in the early stage, and a small amount was also decorated on the floor of indoor halls. From the existing European buildings built in the 18th and 19th centuries in China, it can be seen that the use of mosaic as ground decoration has a decorative effect different from stone slab or terrazzo.
Today, many high-end buildings and halls in China are not satisfied with the effect of only using large stone plates or plate mosaics to decorate the floor. They pursue retro fashion in design concepts and rich and diverse decorative effects, to achieve antique and unique decorative effects; As the material for making mosaics, it has also broken through the situation of a single variety. Resin, shell, glass, and stone have become the materials for making mosaics, and the color is becoming richer and richer.
Among many mosaic materials, marble with a variety of natural colors is the most diverse substrate, and it is also the easiest to make in shape, specification, and splicing pattern. Having these basic elements provides favorable conditions for designing and making exquisite patterns. In this article, we mainly introduce the construction technology of installation, overall strength reinforcement, and flatness grinding of ground small particle marble mosaic.
1、 Characteristic, pavement and reinforcement of traditional mosaic
（1） Characteristics of traditional mosaic
The early mosaic only refers to the ceramic granular building materials made of kaolin and fired at high temperatures. The shape is small square or hexagonal, the thickness is 0.5cm, and the specification is 1cm long and wide or 2cm long and wide;
The color is relatively simple, the dosage is mostly white and black, dark green and dark red are less used, and blue is less;
The fired mosaic particles have the characteristics of brittleness, hardness, and high density, and are hard wear-resistant materials; The front of the particles is smooth and the back is rough. The dirt on the smooth surface of mosaic can not be accumulated and penetrated and has a certain acid and alkali resistance, so it is mostly decorated in public places such as the toilet floor or steps.
（2） Paving, reinforcement, and decorative effect of traditional mosaic
1. The bonding between traditional mosaic and plate is contrary to the current practice of mosaic pasting back net. The plate of the traditional ceramic mosaic is pasted on the front (smooth surface) of the component. The plate is thick kraft paper, and the bonding material is water-based adhesive with weak cementation. Generally, the size of each plate is 30cm × 30cm；
Regardless of the size of mosaic particles, the gap is the same; The bonding between the plate and the mosaic smooth surface is conducive to the bonding between the back (rough surface) of the particles and the cement.
2. Installation and reinforcement of traditional mosaic
The installation and reinforcement of mosaics are completed at one time. First of all, before the mosaic installation, the leveling of the base layer, that is, the mortar layer, is still important, and the flatness of the leveling layer (including the corners) must be accurate; Secondly, after the initial set of leveling mortar, wipe a certain thickness of plain cement slurry, and then install mosaic plates according to them, and pat them with wooden crab (wooden trowel).
3. After the cement is solidified, the viscose under the kraft paper on the mosaic surface shall be fully wetted and softened by the water spraying method. After the kraft paper is removed, the gap shall be repaired with cement slurry cleaning, and finally, the surface shall be rubbed with sawdust to remove the residual glue. The traditional process makes the scraping of cement slurry, mosaic installation, and reinforcement completed at one time. The process is simple and the strength of components is high.
2、 Characteristics of marble mosaic and current situation of paving and installation
1. Characteristics of small grain marble mosaic
As far as the current requirements for decoration and material selection are concerned, for exquisite and delicate mosaic patterns, 1cm long and wide, 0.5era thick small particle marble mosaic is generally selected as the base material for mosaic. However, the marble mosaic of LCM specification has congenital defects: firstly, the particle thickness difference is largely due to the stone cutting error, and the maximum difference of particle thickness on a board surface can reach 0.3cm;
Secondly, the gap is not clear, many particles are almost densely spliced, and even if there is a gap, it is of different sizes; The third is that the cementation material used for the back net is oily adhesive. More than half of the mesh holes in the gap of the back net are closed by the back glue, and the cement mortar cannot be squeezed into the mosaic gap from the back. All these have a direct impact on the decorative effect and the strength of components after installation.
2. Present situation of marble mosaic paving and installation
Now the marble mosaic paving method is similar to the traditional mosaic paving method, but the difference is that the bonding effect of the bonding material between the back net and the base course is poor, the particles are not connected with the bottom slurry, and the paving construction has no function of overall strengthening the particle strength. The specific paving procedures are:
First, remove the garbage from the base course and spray water to wet the mortar layer; The second step is to evenly scrape and level the prepared glue containing mortar on the base surface, then place the mosaic of the whole plate, tap the component surface with an iron plate, and the pavement is completed. After the cement material passes the curing period, the 2cm mosaic with a regular gap shall be scraped and filled with sealant, but the small particles with LCM specification cannot be reinforced because of their fine gap, and the general slurry cleaning cannot be filled;
Even if a few gaps can be filled in batches, they will also cause gaps of different colors. Compared with the traditional pavement effect, the construction method is the same, but the effect is very different. as a result of:
1. The adhesive force between the back net and the base course is not strong, that is, the back net with the oily adhesive surface is bonded with the water-based adhesive of the base course, which is easy to cause hollowing of components;
2. The back mesh lattice is closed by back glue, the particles are only cemented with the back mesh, cannot be connected with the bottom slurry, the periphery cannot be filled and reinforced, and it is easy to thresh;
3. The gap is not standardized, and there is no decorative effect of the granular profile;
4. Due to the inconsistent particle thickness, the mosaic particles after installation are uneven and the decoration effect is poor. This shows that the current paving and installation construction has not developed a new construction method according to the characteristics of profiles, resulting in the lack of due strength and decorative effect of components.
