In recent years, after years of construction engineering practice, it has been proved that the use of cast-in-place terrazzo floor has the advantages of high strength, smooth surface, easy maintenance and cleaning, easy to reflect the decorative effect and low cost after construction. It is widely used in the design of building floor projects.
Terrazzo floor is a composite floor material made of cement as a binder, crushed stone, glass, quartz stone and other aggregates, and then ground and polished on the surface.
What is polished terrazzo floor:
Raw Materials for Polished Terrazzo Floors
Cement:
White cement is used as a cementing material for light-colored terrazzo construction;
Organosilicone alkaline cement is used as a cementing material for dark-colored terrazzo construction
Mineral pigments:
Mineral pigments can play a role in coloring in terrazzo. The amount of pigment used is generally 3% to 6% of the total cement content, or the amount used is reasonably determined by actual test methods, and the pigment is required to have good light resistance and good alkali resistance.
Stone particles:
Terrazzo aggregate, generally with a particle size of 4~14mm, and opaque. The raw materials of stone particles are generally made of granite, marble or dolomite. The stone particles should be hard and free of debris.
Dividing strips:
There are two common dividing strips. One is glass strips. The length of the glass strips is determined by the terrazzo grid size, and the width is determined by the terrazzo surface thickness. The glass thickness is generally 3mm; the other is copper strips. The length of the copper strips is determined by the engineering grid size, and the width is determined by the horizontal terrazzo surface thickness, generally 10 mm.
Sand:
Terrazzo sand is generally medium sand, which must not contain any impurities, and the mud content must not exceed 3%. During use, it is required to use a sieve with an aperture of 8mm for screening.
Oxalic acid:
Oxalic acid is toxic and corrosive, harmful to the human body, and must be diluted with clean water before use. Be very careful during use to avoid contact with the skin and food and drinking water.
Control of polished terrazzo floor construction process
The construction procedures of terrazzo base leveling are: laying out and leveling, installing pipelines and pre-buried, cleaning the base, brushing cement slurry, marking reinforcement, and finally laying leveling mortar for leveling. In the construction process of terrazzo, the treatment of the base is very important. If the base is not treated well, it may cause cracks in the terrazzo surface layer and even cause local collapse.
The leveling treatment method of the base layer for the construction of terrazzo surface layer is the same as the leveling treatment of the general ground cement mortar surface layer. Before construction, all kinds of debris on the base layer should be thoroughly cleaned to avoid affecting the bonding between the surface layer and the foundation. Cracks in the floor slab should be treated to prevent leakage. The viscosity of various cement mortars laid on the base layer should be appropriate, and the mixing must be fully and evenly mixed. Mechanical mixing should be used as much as possible. Watering should be sprinkled for maintenance within 24 hours after the ground is leveled. The watering maintenance period is generally 2 to 3 days, and the grid strips can be constructed only after the strength meets the requirements.
Laying cement mortar leveling layer
Embedding the grid strips
Terrazzo grid strips are generally fixed with cement slurry. When installing, special attention should be paid to the horizontal elevation and angle of the upper part and its horizontal elevation. After the grid strips are installed, the horizontal elevation of the upper part should be slightly lower than the height of the cement gravel slurry construction surface, generally 1 to 2 mm lower. A certain gap should be left between the lower part of the grid strips and the ground. The purpose of this construction is to make the stone particles closer to the grid strips when laying the surface cement mortar. After polishing, there is a better decorative effect.
Laying cement gravel slurry
When the cement strength of the fixed grid strips reaches the specified requirements, cement gravel slurry can be placed. Before construction, all garbage, accumulated water, floating slurry, etc. should be cleaned up, and then a layer of plain cement slurry should be sprayed on the upper part before laying cement gravel slurry.
At the beginning of the laying work, evenly spread an appropriate amount of cement mortar and stone particles within 10 cm on both sides of the grid strips to prevent the grid from shifting. When different colors and types of terrazzo are on the same ground, the darker color should be constructed first, and the lighter color should be constructed later. The large surface should be laid first, and the small surface should be laid later.
During the construction process, a special person should be assigned to manage the terrazzo with admixtures. Before the formal construction, a sample should be made first, and the construction can be carried out after confirmation by the construction party, the design party, etc. After the cement mortar stone concrete foundation is constructed, it should be compacted by a roller.
The time when terrazzo starts to be polished will affect the strength of the cement slurry, and its strength is related to the working environment temperature. The strength of terrazzo should be moderate when polishing. A higher cement slurry strength will cause the grinding surface to consume time; when the strength does not meet the design requirements, the stone particles will fall off during polishing. When it is at room temperature, the polishing construction can be started 2 to 3 days after the cement stone slurry construction is completed.
When polishing, the grinding disc should be kept in a water state to wash the stone slurry. Due to the loose construction of the cement stone slurry, local slight pores appear after the terrazzo is formed, which can be treated by grouting.
The terrazzo floor should be polished three times and re-slurried twice during the polishing process. Under normal temperature, the first polishing should be carried out 2 to 3 days after the cement stone slurry is laid. The first polishing requires that the terrazzo floor be roughly smoothed, the pattern shape of the terrazzo should be clearly visible, and the defective parts should be re-slurried in time; the second polishing should be carried out 2 to 3 days after the first polishing. The polishing should eliminate the wear marks, and then repair the local small defects. The third polishing is carried out 2 to 3 days later. The last polishing is the key to the molding quality. It requires the stone particles to be evenly exposed, the surface to be smooth, and no pores, with good visual quality.
Polished Terrazzo Floor
The last process of polishing terrazzo construction is the key to achieving good visual quality. Polishing has both physical and chemical reactions. Under the action of the polishing liquid, it reacts chemically with the protruding parts of the surface, and squeezes the product into the concave parts. After a series of physical and chemical reactions, a layer of gloss film will be formed on its surface. After waxing protection, the terrazzo floor presents a lasting gloss. Waxing should be done after the surface is completely dry. Before waxing, spray oxalic acid liquid on the surface, the solution concentration is generally 10%, then polish it once, rinse it with clean water, and wax and polish it after the ground is dry.
