What does the construction process of current terrazzo on the ground include?

Sourced from the Internet for reference only. Scope: This process standard is applicable to ordinary and advanced ready-made terrazzo floor projects in industrial and civil buildings. Construction preparation 2.1 Materials and main machines: 2.1.1 Cement: The white or light-colored terrazzo surface layer should be made of white cement. The dark-colored terrazzo surface layer should be made of Portland cement, ordinary Portland cement or slag Portland cement. Its label should not be less than No. 425. Surface layers of the same color should use the same batch of cement. 2.1.2 Mineral pigments: The pigments mixed into cement should be light-resistant and alkali-resistant mineral pigments, and acidic pigments must not be used. The mixing amount should be 3% to 6% of the cement weight, or determined by testing. The same colored surface layer should use pigments from the same factory and batch. 2.1.3 Stone particles: It should be processed from hard and grindable dolomite, marble and other rocks. The stone should be clean and free of debris. Unless there are special requirements, the particle size should be 4 to 14 mm. 2.1.4 Grid strips 2.1.4.1 glass strip: It is cut from flat ordinary glass, 3mm thick, usually 10mm wide (depending on the thickness of the surface layer), and the length is determined by the block size. 2.1.4.2 copper bar: Cut the l~2mm thick copper plate into 10mm width (depending on the thickness of the surface layer). The length is determined by the grid size. It must be straightened and leveled before use. 2.1.5 Sand: Medium sand, passed through a sieve with an aperture of 8mm, the mud content shall not exceed 3%. 2.1.6 Oxalic acid: Available in lump or powder form, dilute with water before use. 2.1.7 White wax and No. 22 iron wire. 2.1.8 Main machines and tools: Terrazzo machine, roller (diameter is generally 200-250mm, length is about 600-700mm, made of concrete or iron), wooden trowel, brush, iron dustpan, ruler, trolley, flat shovel, 5mm aperture sieve, oilstone (specification according to coarse, medium and fine), rubber water pipe, large and small buckets, broom, wire brush, iron tools, etc. 2.2 Working conditions: 2.2.1 The plastering on the ceiling and walls has been completed and accepted, and the waterproof layer on the roof has been completed. 2.2.2 The door frame has been installed and protected, the water and electricity pipelines related to the ground have been installed in place, and the pipe holes passing through the ground have been blocked tightly. 2.2.3 After completing the ground cushion, leave a grindstone layer thickness (at least 3cm) according to the elevation. 2.2.4 Stone particles should be sieved separately and washed without debris. Operation process 3.1 Process flow: Base course treatment → Find the elevation → Spread the horizontal line → Spread the leveling layer mortar → Maintenance → Spread the grid lines → Set the grid strips → Mix the terrazzo mixture → Apply the cement slurry bonding layer → Spread the terrazzo mixture → Rolling and smoothing → Trial grinding → Rough grinding → Fine grinding → Polishing → Oxalic acid cleaning → Waxing and glazing 3.1.1 Base course treatment: Clean the debris on the concrete base, and there should be no oil stains or floating soil. Use a steel chisel and a wire brush to chisel off the cement slurry stained on the base layer. 3.1.2 Find the elevation and bounce the horizontal line: According to the +50cm elevation line on the wall, measure the elevation of the grindstone surface downwards and bounce it on the surrounding walls. Also consider the elevations of other rooms and passage surfaces to make them consistent. 3.1.3 Apply leveling mortar: 3.1.3.1 According to the horizontal lines that pop up on the wall, leave a thickness of the surface layer (about 10~15mm thick), and apply a 1:3 cement mortar leveling layer. In order to ensure the flatness of the leveling layer, first plaster the cake (the vertical and horizontal spacing is about 1.5m), with a size of about 8~10cm. 3.1.3.2 After the ash cake mortar hardens, use the height of the ash cake as the standard to apply vertical and horizontal ribs with a width of 8 to 10 cm. 3.1.3.3 Sprinkle water on the base layer to moisten it, and apply a layer of cement slurry with a water-cement ratio of 0.4 to 0.5. The area should not be too large. Apply 1:3 leveling mortar along with the slurry, and use a 2m long scraper to scrape the base according to the standard rib, and then rub it flat with a wooden trowel. 3.1.4 Maintenance: After the leveling layer mortar is applied, it is cured for 24 hours. Only when the compressive strength reaches 1.2MPa can the next construction process be carried out. 3.1.5 Elastic grid lines: According to the grid size required by the design, lm×lm is generally used. Play the crosshair in the middle of the room. After calculating the width of the surrounding border, use the crosshair as the guideline to play the grid lines. If the design has pattern requirements, clear lines should pop up according to the design requirements. 3.1.6 Inlaid grid strips: Use a small iron trowel to apply thick cement slurry to fix the partition strips (the partition strips are installed on the partition lines) and form a 30° figure-eight shape (Figure 7-1). The height should be 4 to 6 mm lower than the top of the partition strips. The partition strips should be straight (the upper level must be consistent), strong, with tight joints, and no gaps, as a sign of laying the surface layer. In addition, when pasting the grid strips, in order to fully fill the mixture at the cross joints of the grid strips, do not apply cement slurry within 40 to 50 mm from the intersection (Figure 7-2). 3.1.11 Trial grinding: Generally, the number of maintenance days is determined according to the temperature. When the temperature is between 20 and 30°C, machine grinding can be started in 2 to 3 days. If the stone is ground too early, it will easily loosen. ； Too late makes polishing difficult. Therefore, test grinding is required to ensure that no stones fall off the surface layer. 3.1.12 Coarse grinding: For the first pass, grind with No. 60 to 90 coarse diamonds, and make the grinding machine head make a horizontal "8" shape on the ground. Add water while grinding (if the curing time of the grinding stone surface is too long, you can add fine sand to speed up the machine grinding). Clean the cement slurry at any time, and use a ruler to check the flatness until the surface is smooth, even and divided. All the strips and stone particles are exposed (the edges and corners are manually ground to the same effect), washed with water and dried, and then wiped with thicker cement slurry (such as a surface layer mixed with pigments, use cement slurry with the same mix of pigments). Especially the holes and small pores in the surface layer should be filled and smoothed, and the fallen stone particles should be repaired. Water and maintain for 2 to 3 days. 3.1.13 Fine grinding: For the second time, use No. 90 to No. 120 diamond to grind until the surface is smooth. Then rinse it with clean water, rub the cement slurry fully for the second time, still paying attention to the small pores to rub carefully and tightly, and then maintain it for 2 to 3 days. 3.1.14 Polishing: For the third time, use a No. 200 fine diamond to grind until the stones on the surface are evenly exposed, with no missing stone particles, flat, smooth, and without pores. The number of polishing passes for the ordinary terrazzo surface layer should not be less than three times. The thickness and number of polishing passes for the advanced terrazzo surface layer and the specifications of the oil stone should be determined according to the design. 3.1.15 Oxalic acid scrubbing: In order to obtain a significant effect after waxing, the surface of the grindstone must be pickled to an appropriate amount before polishing. Generally, it is scrubbed with oxalic acid. When using it, first add oxalic acid to water to form a solution with a concentration of about 10%, dip it with a broom and sprinkle it on the ground, and then grind it gently with a whetstone. ； Grind out the true color of cement and stone particles, then rinse with water and wipe dry with a soft cloth. This operation must be carried out after each type of work is completed, and the surface layer after pickling must not be contaminated again. 3.1.16 Wrong glazing: Wrap the wax in a thin cloth and apply a thin layer on the surface. After it dries, replace the oil stone with a piece of wood nailed with canvas or linen, grind it on a grindstone, and use the same method to apply the wax a second time until it is smooth and bright. 3.1.17 When constructing the existing terrazzo surface layer in winter, the ambient temperature should be kept above +5℃. 3.1.18 Terrazzo skirting boards: 3.1.18.1 Apply primer: The thickness of the plastering on the wall should be the same. Use squares, measuring tapes, and pull wires at the yin and yang corners to determine the thickness of the skirting board. Punch the ribs according to the thickness of the bottom layer of ash, with a spacing of 1 to 1.5m. Then use a short pole to scrape the files flat, rub them into pits with a wooden trowel and scratch them. 3.1.18.2 Troubled stone baseboard mix: First, moisten the base plaster with water. Use a ruler to find the rules according to the horizontal line at the yin and yang corners and the upper mouth. Attach the ruler board. First apply a thin layer of cement slurry, then apply the mixture, smooth and compact. Brush water twice to gently remove the cement slurry until there is no floating slurry on the gravel surface. After curing at room temperature for 24 hours, manual grinding begins. Use a coarse oilstone for the first time, grind vertically and then horizontally. It is required to smooth the gravel, round the yin and yang corners, rub the first pass of plain ash, fill the pores densely, and maintain it for 1 to 2 days. Then grind it for the second time with a fine oilstone. Use the same method to grind the third time. Use the oilstone to polish oxalic acid and scrub it clean with water. 3.1.18.3 artificial wax: Rub it twice and the light will come out alive. Quality Standard 4.1 Guarantee Items: 4.1.1 Select materials: The variety, strength (mix ratio) and color should comply with the design requirements and construction specifications. 4.1.2 The connection between the surface layer and the base layer must be firm and free of defects such as hollows and cracks. 4.2 Basic items: 4.2.1 Surface layer: 4.2.1.1 Ordinary terrazzo: The surface is smooth, without cracks, blisters or abrasions. The stone grains are dense and evenly exposed. The pattern meets the design requirements. The color is consistent and does not mix colors. The grid bars are firm, clear and straight. 4.2.1.2 High grade terrazzo: The surface is smooth and smooth, with no cracks, blisters or abrasions. The stone grains are dense and uniform in appearance. Adjacent colors do not mix. The grid bars are firm, straight and clear. The edges of the yin and yang corners are square. 4.2.2 Skirting boards: 4.2.2.1 Ordinary terrazzo: The height is consistent, the thickness of the wall is even, and it is firmly combined with the wall. Although there are hollows in some parts, their length is not more than 200mm, and there are no more than 2 places within an inspection range. 4.2.2.2 High grade terrazzo: The surface is smooth and clean, firmly combined with the wall, the wall thickness is consistent, and the upper opening is straight. 4.2.3 The width and height difference between two adjacent steps of stairs and steps should not exceed 10mm, the corners should be neat, and the anti-slip strips should be straight. 4.2.4 Floor edging: 4.2.4.1 Ordinary terrazzo: The materials and dimensions of the edging should comply with the design and construction specifications. The corners should be neat and smooth, and the colors of different surface layers should not mix adjacent to each other. 4.2.4.2 High grade terrazzo: The size is correct, the splicing is tight, the adjacent colors do not mix, the color separation lines are straight, and the corners are neat, smooth, clear and beautiful. 4.2.5 Waxing quality: The wax is spread evenly without revealing the bottom, the color is consistent, the thickness is even, smooth and bright, the pattern is clear, and the surface is clean. 4.3 Allowable deviation items, see Table 7-6. Table 7-6 Allowable deviation of existing terrazzo floor Allowable deviation (mm) Ordinary advanced surface flatness 3 2 Use a 2m ruler and wedge feeler gauge to check the straightness of the skirting line 3 3 Pull a 5m line, and pull out a line gauge of less than 5m to check that the joints are straight 3 1 Pull a 5m line, and pull out a line gauge of less than 5m to check the finished product protection 5.1 When laying the cement mortar leveling layer, be careful not to damage water, electrical pipelines and other equipment. 5.2 Pay attention to protecting the door frame when transporting materials. 5.3 When machine grinding the terrazzo surface layer, the ground cement waste slurry should be removed in time and must not flow into the drain and floor drain to prevent blockage. 5.4 The stone grinding machine should be equipped with a cover to prevent walls and facilities from being splashed during grinding. Important parts and equipment should be covered. Quality issues that should be noted 6.1 The dividing strips are broken and unclearly exposed: The main reason is that the partition strips are not firmly inlaid (or not lower than the surface layer), and the iron trowel is not used to tap both sides of the partition strips before hydraulic pressure. During the roller rolling process, the partition strips are bent or crushed. Therefore, in order to prevent this phenomenon from happening, the stones on both sides of the dividing strip must be gently patted down before rolling. 6.2 There are no stones in the four corners of the intersection of the dividing strips.: The main thing is that when bonding the partition strips, the thick cement slurry should be bonded at an angle of 30°, and the top of the partition strips should be 4 to 6 mm away from the cement slurry. At the intersection of the partition strips, the bonding slurry should not be applied to the edge, and there should be pores for the mixture to be applied. 6.3 There are holes and pores in the terrazzo surface layer: Some holes will always appear after the terrazzo surface is machine-polished. Generally, the grouting method is used, that is, rinse it with clean water after polishing, and use thicker cement slurry (for example, when using colored terrazzo surfaces, apply the same color pigment and cement to wipe it) to make the holes dense, and then polish them after hardening. ； Ordinary terrazzo surface layer uses the "two slurry and three grinding" method, that is, the whole process is polished three times and slurryed twice. If you wipe it once less to save trouble, or use a broom to sweep instead of wiping or using slurry, it will easily cause small holes in the surface layer (in addition, since the mortar is polished before it hardens after wiping, it is also easy to grind away the mortar in the holes). 6.4 The surface stone particles are uneven and not exposed: The main reasons are that the stone specifications are not good, the stone particles are not cleaned, and the stone particles are buried in the mortar when scraping with a scraper when laying the mixture, resulting in uneven stone particles. Quality records This process standard should have the following quality records: 7.1 Factory certificate of cement and stone. 7.2 Quality assessment data for grindstone surface layer sub-projects.