What does it mean to pave marble flat joints in squares?

Square stone paving must leave expansion joints or settlement joints starting from the structural layer

The distance between expansion joints can be appropriately enlarged

1 Construction technology standards for square paving 1 Scope of application This process standard is applicable to the paving project of large-scale natural stone and artificial stone outdoor square tiles. 2 Construction Preparation 2.1 Materials 2.1.1 The varieties and specifications of natural stone and artificial synthetic stone should meet the design requirements, and the technical grade, gloss, and appearance quality requirements should comply with the national standards. 2.1.2 Cement: Generally, ordinary Portland cement or Portland cement is used, and there is a factory certificate and retest report. 2.1.3 Sand: Coarse sand or medium sand, passed through an 8mm aperture sieve, its mud content should not be greater than 3 (for cement mortar). Fine sand, pass through a 2mm aperture sieve (for joint filling). 2.1.4 Water: Drinking water should be used. When other water sources are used, they should be tested according to relevant standards and used after confirmation. 2.2 Equipment and tools 2.2.1 Machinery: mortar mixer, forklift, special trolley 2.2.2 Tools: iron trowel, wooden trowel, ruler, slurry pot, half vat, sprinkler can, steel tape measure, nylon rope, rubber hammer ( or wooden hammer), broom, steel chisel, iron hook, grinding saw, scraper, sledge hammer, rubber pad, etc. 2.3 Operating conditions 2.3.1 After the natural stone enters the site, first check in detail whether the variety, specification, quantity, etc. meet the design requirements. If there are cracks, missing edges, dropped corners, color differences, and surface defects, they should be removed. Then use a forklift to load and unload the stone at the designated location, and square wood should be placed under the stone. 2.3.2 The concrete base construction has passed the acceptance inspection and the acceptance procedures have been completed. 2.3.3 The compressive strength of the concrete base layer reaches above 2.5Mpa. 2.3.4 The surface of the concrete base should be smooth, solid, rough, and clean. The floating soil, floating slurry and other pollutants on the surface should be cleaned and fully moistened, and there should be no accumulation of water. 3 Operation process 3.1 Process flow

Measurement and laying out→Concrete base treatment→Initial leveling of paving mortar and initial leveling of stone paving

→Stone paving→Stone joint filling→

Stone surface cleaning 3.2 Operation method 3.2.1 Measurement and setting out: 3.2.1.1 Square plane control: plane control is divided into three levels. The first level is set up by the Surveying and Mapping Institute to determine the main axis position and Arrange points around the construction site; at the second level, lay out a level 2 building plane rectangular grid around the construction site (accuracy requirements are: error in angle measurement ±1/10000); on the basis of the second level control network, press The area within 10m is divided into three levels of square grid to form a square grid control to meet the measurement and design requirements of field control. During the paving construction, the pile positions are encrypted according to the outer contour of the rectangular mesh, the control piles are measured to the construction area, nailed and measured, and the closure is checked after each closed figure is measured. 3.2.1.2 Square elevation control: The Surveying and Mapping Institute will lay out a national second-level network along the perimeter of the square as the first-level elevation control network. The construction unit used the closed leveling method to densely lay out elevation control points in the construction area based on the leveling point elevations provided by the Institute of Surveying and Mapping and in accordance with the national third-class leveling technical requirements. First, calculate the elevation of the intersection point between the maximum slope line of the square contour line and the edge of the small square grid, and use it as the measurement data in tabular form. 2. Use a laser sweeper and a level to control the elevation layer by layer. During the actual on-site measurement, the elevation point was measured based on the calculated data on the Φ10 steel bar measuring drill, and nylon wire with good stretchability was used as the basis for construction elevation control. 3.2.2 Concrete base treatment: Clean the dirt and debris on the concrete base, use a wire brush to brush off the mortar adhered to the surface of the base, and clean it. If there is any oil stain, use detergent to clean it.

3.2.3 Initial leveling of paving mortar and stone paving: first sprinkle water with a watering can to moisten it, and then apply a layer of plain cement slurry with a water-cement ratio of 0.4~0.5. Do not apply too large an area. Apply the mortar along with the laying, according to the horizontal line of the stone. Determine the thickness of the mortar of the binding layer. The thickness of the mortar is generally about 10-20mm higher than the bottom elevation of the stone. The dry hard cement mortar of the binding layer generally uses 1:2~1:3 dry hard cement mortar. The dry hardness is kneaded into a ball by hand. It is advisable to scatter the stone as soon as it hits the ground. Use a wooden trowel to level it and place the stone in place, and then try to tamp the stone to the design elevation. If the thickness deviation of the mortar is found to be too large through trial tamping, lift the stone to adjust the thickness of the mortar. 3.2.4 Stone paving: Before stone paving, stone paving should be started at the intersection of the cross control lines according to the numbers and patterns in the square plane grid control diagram. On the initially leveled dry hard mortar, pour a full layer of plain cement slurry with a water-cement ratio of 0.5 (use a mortar pot to pour evenly), and then place the stone. When placing the stone, the four corners will fall at the same time. After the stone is placed, adjust the position of the stone with a sledge hammer. (It is required to place a rubber pad on the surface of the stone), wooden tampers cooperate with each other, and hammer the stone to make it meet the quality requirements of the design elevation, flatness, and height difference between adjacent boards. During the hammering process, attention should be paid to adjusting the position of the stone at any time. , keep the longitude and latitude directions straight. After paving the vertical and horizontal rows and having standards, the paving can be done in sections and in different sections. 3.2.5 Stone joint filling: Fill the joints 1-2 days and nights after the stone is laid. The stone joints are filled with 1:10 cement dry sand and swept joints. After filling the joints, water the entire area of ??the paved square bricks so that the dry cement sand in the stone joints can fully sink and become dense before filling the joints a second time. 3.2.6 Stone surface cleaning: After the secondary joint filling is completed, water and clean the stone surface. 3.3 Seasonal construction: When this process is operated in the open air, it is not suitable to be constructed on rainy days. The construction temperature in winter should not be lower than 5℃. 4 Quality standards 4.1 Basic requirements: Stone material varieties and specifications comply with design requirements and construction specifications; cement and sand mix ratios and their practices must comply with design requirements and construction specifications; the stone surface layer is closely integrated with the next layer, and the paving is smooth It is stable, the grouting joints comply with the design requirements, the paving surface is connected to the structure, and there is no reverse slope. 4.2 Table 4.2 Allowable deviation of actual measured items Table 4.2

Allowable deviation of items (mm) Detection frequency Detection method range Number of points Control line elevation ±8 20m×20m 3 Use a level to measure flatness ≤4 20m×20m 3 Use 3 Use a ruler and feeler gauge to measure the maximum height difference between adjacent blocks ≤ 2 20m×20m 3 Use a ruler and feeler gauge to measure the maximum vertical and horizontal slope ±0.2 20m×20m 3 Use a level to measure the straightness of vertical and horizontal joints ≤ 5 40m 3 Pull 20 meters of thread to measure the maximum seam width 3, -2 20m×20m 3 Use a feeler gauge to measure the maximum value 4.3 Appearance identification No cracks, no missing edges, no falling corners, no color difference, clean and beautiful surface, natural and coordinated colors . 3 5 Finished product protection 5.1 When using a small forklift to load and unload stone, it is necessary to arrange for experienced drivers to carry out loading and unloading operations, to lift and place with care, and to arrange for dedicated personnel to direct. 5.2 A single stone requires four people to lift and transport a single stone with a steel wire rope or double iron wire. The corners of the stone are easily worn away by the steel wire rope. Therefore, equal-angle steel or wooden boards are added to the corners where the steel wire rope contacts the stone to protect the stone. 5.3 When ramming stones, the surface of the stone must be paved with rubber blocks or scrap tires to avoid damage to the stone during the ramming process. 5.4 Within 3 days after the stone paving is completed, it is strictly prohibited for any vehicle to drive or perform construction work on the stone surface to prevent pressure damage and oil pollution on the stone surface. 5.5 During the process of paving stone, operators should use a dry cloth to wipe away traces of cement slurry on the surface of the stone as soon as it is laid. 6 Quality issues that should be paid attention to 6.1 In order to prevent the size of the stone from exceeding the standard, the corners of the stone being chipped and the stone color difference, it is necessary to strengthen the three-level inspection of the stone factory inspection, on-site inspection, and paving process inspection.

6.2 Hollow drum: In order to prevent the dry hard mortar from being not dense and locally uneven, a small scraper should be used to smooth it. 6.3 Cracks: In order to prevent the occurrence of cracks in the stone, rubber blocks should be placed when tamping the stone or the ramming force should be prevented from being too strong. 6.4 The height difference of adjacent stones exceeds the standard: Strictly control the thickness of the stone mortar and the number of stone ramming times. 6.5 In order to prevent the stone material from being filled with loose joints, it is necessary to ensure that the stone material is filled with dense material and fully sprinkled with water. 7 Quality records 7.1 Factory certificate and test report of raw materials (stone, cement, sand, admixtures, etc.). On-site acceptance record. 7.2 Process handover inspection records. 7.3 Hidden inspection records. 7.4 Project inspection batch inspection records. 7.5 Quality inspection and assessment of sub-projects. 7.6 Unit project quality inspection records. 7.7 Construction Records. 7.8 Design changes and negotiation records. 7.9 Other technical documents. 8 Safety and environmental protection measures 8.1 Safe operation requirements 8.1.1 Workers who have not received training and education on production safety are not allowed to work. Special types of work require certificates. 8.1.2 Personnel not related to the construction are strictly prohibited from entering the site. Personnel entering the site should wear safety helmets. 8.1.3 Hang eye-catching safety slogans at the construction site and set warning signs at dangerous locations. 8.1.4 Establish a responsibility area system at the construction site, designate responsible persons, and set up signboards. 8.1.5 All types of protective devices for construction machinery are complete. 8.1.6 The on-site power distribution lines must not have aging and leakage. Special brackets are required for the direction of the cables. They must not be pulled in bunches or crawled all over the ground. The places crossing the road must be protected. 8.1.7 Mobile mechanical equipment and handheld power tools are equipped with leakage protectors; the leakage protectors are qualified and reliable; the metal shells of various machines and tools must be connected to zero protection. 8.1.8 Floodlights should be used for night construction lighting, and measures should be taken to prevent rain and snow. 8.2 Environmental protection measures