Can self-leveling cement be used directly as a floor?

    The determination of the initial setting time of concrete and the entry timing of laser levelings are directly related to the quality, efficiency and cost of floor construction. Now I will provide you with a detailed analysis of these two core points. The "initial setting" of concrete is a physicochemical process, referring to a point in time when concrete begins to transform from a plastic state to a solid state, rather than a period of time. In terms of standards, the initial setting time refers to the period from the moment water is added and mixed until the concrete loses its fluidity and begins to set. Judgment methods and criteria This is the method stipulated in the national standard (GB/T 50080), which is usually carried out in the laboratory or at important construction sites. Method: Use a penetration resistance meter to penetrate the mortar screened out from the concrete mixture at a specified speed. When the penetration resistance reaches 3.5MPa, the corresponding time is the initial setting time. Advantages: The data is precise, objective and reliable. Disadvantages: It requires dedicated equipment, the operation is rather complicated, and it is not suitable for on-site rapid judgment. In actual construction, workers and technicians mainly rely on the following empirical methods to make judgments: Acupressure method (the most classic) : Apply a slight pressure to the concrete surface (usually with the thumb). The criterion for judgment: If, after pressing with a finger, a clear mark about 2-3 millimeters deep can be left on the surface, and the concrete is not sticky to the hand, with no obvious water marks or slurry overflow around, it is considered to have reached the initial setting state at this time. State analogy: It feels like moist clay or plasticine. Scratch method Make a mark on the concrete surface with a nail, a screwdriver or your finger. The criteria for judgment: The scratch marks are clear, the edges are neat, and the bottom of the scratch can maintain its shape and will not be quickly filled and healed by the slurry. Footprint method A person walks on the concrete and observes the footprints. Judgment criteria: The depth of the footprints should be around 5 to 10 millimeters, and there should be no obvious cracking or excessive bleeding around the footprints. Vibration rod insertion method Insert the small vibrator into the concrete and then pull it out. The criterion for judgment: The hole formed after being pulled out can basically remain in its original state and will not collapse and close rapidly. Important note: The on-site experience method requires construction personnel to have certain experience. The best practice is to make a comprehensive judgment by combining multiple methods and compare it with the estimated initial setting time provided by the laboratory. The entry timing of the laser leveling must be closely coordinated with the setting state of the concrete. Entering the market too early or too late can lead to serious problems. Question Sinking: The tracks or wheels of the leveling may get stuck in the concrete, causing deep ruts and disrupting the flatness. Bleeding: The equipment's rolling will force water and fine particles to float up, forming a surface slurry layer, which leads to dusting, sanding and insufficient strength in the later stage. The concrete cannot support the weight of the equipment, and the leveling head cannot be effectively leveled. Instead, it will disrupt the concrete. Condition description: The fingerprinting mark is very deep (>5mm), or the footprint is deeply sunken, and the scratch heals rapidly. Question Construction difficulties: The resistance of the leveling machine's movement is huge, the engine load is high, and it may even be unable to move. Poor surface quality: The flat head cannot effectively smooth out the already hardened surface, leaving marks of roughening and cracking, which damages the integrity of the surface. Poor joint: It cannot bond well with the subsequent poured concrete, resulting in cold joints. Ineffective compaction: The concrete has lost its plasticity, and the vibration of the leveled head cannot make it compact again. Condition description: There is almost no mark when pressed by finger, or a very strong force is needed to leave a shallow mark. The edge of the scratch will crack. The laser leveling should be put into operation when the concrete reaches the initial setting state, or slightly earlier than the initial setting (that is, close to the initial setting but not yet fully reached). Specific timing to grasp Core standard: When using the finger press method and the depth of the finger press impression is around 3-5mm, it is the best time for the leveling to enter the site. Operation process connection: The ideal construction process is: The preparatory processes: concrete spreading, initial vibration, and leveling with scraping bars have been completed. Wait for the right moment: Let the concrete stand naturally, bleed water and evaporate, gradually developing towards the initial setting state. During this period, workers can carry out manual operations such as edge and corner treatment. Judgment and entry: The construction supervisor continuously observes the condition of the concrete. Once it reaches the aforementioned "golden finger pressure standard", they immediately direct the laser leveling machine to enter the site. High-efficiency operation: The leveling, with its highly efficient functions of scraping, vibrating and leveling, can quickly complete large-scale operations when the concrete is still plastic but capable of supporting the weight of the equipment at its optimal state. Prediction is key: Before construction, it is necessary to understand the mix ratio of the concrete to be used and the estimated initial setting time measured in the laboratory (for example, at 20℃, the initial setting time of ordinary concrete is approximately 4 to 6 hours). This provides a time reference for on-site judgment. Environmental factors: Temperature, humidity and wind speed have a significant impact on the initial setting time. High temperature, strong wind and low humidity will shorten the initial setting time. It is necessary to prepare in advance to reduce the waiting time. Conversely, it will be extended. Personnel and Communication: A designated person (such as a foreman or technician) must be assigned to determine the initial setting time and maintain smooth communication with the equipment operator. It's better to arrive a little earlier than too late: When it's impossible to make an accurate judgment, entering the site a little earlier (the concrete is slightly softer) might just require dealing with the track indentations. However, if the entry is too late and the concrete becomes too hard, the quality problems caused are almost irreversible and the handling cost is extremely high. In short: When you "feel" the concrete with your hand and it feels like a moist and solid piece of clay, that's the best time for the laser leveling to shine. Accurately seizing this opportunity is the core technology for creating high-level and high-quality concrete floors. Note: The parameters provided in this document are for reference only and are not mandatory. Due to differences in technical characteristics between different brands and models of laser levelers, please consult the manufacturer for a suitable solution before actual operation. This reference document assumes no responsibility for any issues arising from failure to follow the manufacturer's instructions.    

  What is the frequency of maintenance of concrete laser leveling machine? As an indispensable and important equipment in modern building construction, the diffuse concrete laser leveling machine's performance stability and service life directly affect the construction quality and efficiency. Therefore, it is particularly important to carry out scientific and reasonable maintenance of concrete laser leveling machines. However, many users may have some questions about the frequency of maintenance of concrete laser leveling machines. This article will focus on this issue and elaborate on the key points of daily equipment inspections, periodic maintenance plans, special maintenance needs, lubrication and cleaning, electrical system inspection, replacement of wearing parts, and repair and maintenance records. 1. Key points for daily inspection of equipment Routine inspection is the basic work to ensure the normal operation of the concrete laser leveling, and its frequency should be relatively high. In general, a thorough daily inspection should be performed before and after each use. Key check points include: ☀ Check whether the appearance of the equipment is intact and whether there is any damage, deformation, etc.; ☀ Check whether the fasteners of the equipment are loose. If they are loose, tighten them in time; ☀ Check whether the hydraulic and electrical systems of the equipment are working normally. If there are any abnormalities, they should be dealt with in time; ☀ Check whether the operation control of the equipment is flexible and reliable. If there is any jamming or failure, repair it in time; ☀ Check whether the walking system of the equipment is stable and whether the track is seriously worn, etc. Through daily inspections, problems with the equipment can be discovered and solved in time to ensure the normal operation of the equipment. 2. Periodic maintenance plan In addition to daily inspections, a periodic maintenance schedule should be developed based on the equipment's usage and manufacturer's recommendations. The frequency of periodic maintenance can generally be determined based on the working hours or length of use of the equipment. ☀Weekly maintenance: Conduct a comprehensive inspection of the equipment every week, including checking the oil level and quality of the hydraulic oil, cleaning the radiator and filter, and checking whether the wiring of the electrical system is loose, etc. ☀ Monthly maintenance: Perform more in-depth maintenance on the equipment every month, such as replacing hydraulic oil and filters, checking the engine oil and water tank, etc. ☀ Quarterly maintenance: Conduct extensive maintenance and upkeep on the equipment every quarter, such as checking the wear of the track, replacing severely worn track shoes, checking the sealing of the hydraulic cylinder, etc. By formulating and executing a periodic maintenance plan, the service life of the concrete laser leveling can be effectively extended and its work efficiency improved. 3. Special maintenance needs In some special cases, additional maintenance on your concrete laser leveling may be required. These special circumstances include: ☀ The equipment has not been used for a long time: If the equipment has not been used for a long time, it should be started and operated regularly to prevent parts from rusting or aging due to long-term parking of the equipment. ☀ Harsh working environment: In harsh working environments, such as high temperature, dusty, humid and other environments, the maintenance frequency of the equipment should be appropriately increased to cope with the impact of environmental changes on the equipment. ☀ Equipment failure: When equipment fails, troubleshooting and repairs should be carried out in a timely manner to ensure that the equipment can resume normal operation in a timely manner. For these special circumstances, we need to formulate corresponding maintenance measures and plans based on the actual situation to ensure the normal operation of the equipment and extend its service life. 4. Lubrication and cleaning Lubrication and cleaning are important aspects that cannot be ignored in the maintenance of concrete laser leveling machines. Lubrication can effectively reduce the wear and friction of equipment and extend its service life; while cleaning can prevent equipment failures caused by dust, debris, etc. ☀ In terms of lubrication, all lubrication points of the equipment should be lubricated regularly, such as bearings, chains, etc. At the same time, pay attention to selecting appropriate lubricating oil and grease to ensure the lubrication effect. ☀ In terms of cleaning, dust and debris on the surface of the equipment should be cleaned regularly to keep the equipment tidy. In addition, the radiator and filter of the equipment should be cleaned regularly to ensure the heat dissipation effect and ventilation performance of the equipment. Through reasonable lubrication and cleaning work, the working efficiency and stability of the concrete laser leveling can be effectively improved. 5. Electrical system inspection The electrical system is a critical part of the proper operation of the concrete laser leveling, so regular inspection and maintenance of it is essential. Electrical system inspection mainly includes the following aspects: ☀ Check whether the cable lines are intact and not damaged or aged; ☀ Check the working status of electrical components, such as whether switches, relays, etc. are working normally; ☀ Check the stability and accuracy of the electrical control system to ensure that the operation and control of the equipment are accurate and reliable; ☀ Clean and dust-proof the electrical system regularly to prevent failures caused by dust accumulation. Through electrical system inspection, electrical faults can be discovered and solved in time to ensure the normal operation of the concrete laser leveler. 6. Replace wearing parts During the use of the concrete laser leveling, some wearing parts will gradually wear or be damaged as the use time increases. In order to ensure the normal operation of the equipment and extend its service life, these wearing parts need to be replaced in time. Common wearing parts include blades, scrapers, track shoes, etc. These parts will wear or deform during long-term use, affecting the construction quality and efficiency of the equipment. Therefore, the wear of these parts should be checked regularly and replaced according to the actual situation. When replacing wearing parts, you should choose qualified products produced by regular manufacturers and perform replacement operations in accordance with the requirements of the equipment manual. At the same time, replacement records should be kept for reference in subsequent maintenance work. 7. Repair and maintenance records In order to better understand the maintenance status of the concrete laser leveling machine, it is recommended to establish complete repair and maintenance records. The record content includes basic information of the equipment, maintenance time, content, personnel, and replaced parts and other information. Through repair and maintenance records, you can clearly understand the maintenance history and usage status of the equipment, providing a reference for subsequent maintenance work. At the same time, it also helps to discover potential problems in the operation of the equipment and take timely measures to deal with them to avoid failures. In addition, repair and maintenance records can help improve the efficiency of equipment management. Through the analysis of records, the effectiveness of equipment maintenance can be evaluated, deficiencies in maintenance work can be found, and a more scientific and reasonable maintenance plan can be formulated. When establishing repair and maintenance records, it is recommended to use electronic methods for recording and management. Through the electronic recording system, data can be easily queried, counted and analyzed to improve work efficiency. At the same time, it can also reduce the risk of loss and damage of paper records and ensure the integrity and reliability of data. In summary, the maintenance of concrete laser leveling machines is of great significance to the normal operation and extended service life of the equipment. By formulating reasonable maintenance plans, performing daily inspections and periodic maintenance, paying attention to special maintenance needs, doing lubrication and cleaning work, checking electrical systems, replacing wearing parts in time, and establishing complete repair and maintenance records, we can ensure that The stable operation of the pyrolysis soil laser leveling machine improves construction quality and efficiency. However, it should be noted that the maintenance frequency and content mentioned in this article are only general recommendations, and actual operations need to be adjusted and improved according to the specific conditions of the equipment, the use environment and the manufacturer's recommendations. At the same time, maintenance work should be performed by professionals with corresponding qualifications and experience to ensure correct, safe and effective operations. Finally, we hope that the discussion in this article can provide some reference and help for the maintenance of concrete laser levelings, and contribute to the stable operation and extended service life of the equipment.

– When the trowel speed is moderate, it can effectively flatten the raised parts of the concrete surface and fill the sunken parts. For example, in general indoor floor construction, if the trowel speed is set in a suitable range, such as 70-100 rpm, the blade on the trowel can initially level the newly poured concrete surface as the trowel moves forward. Because at this speed, the pressure and flattening effect of the blade on the concrete are relatively uniform, and it will not be over-cut due to too fast a speed, nor will it be unable to effectively deal with the unevenness of the surface due to too slow a speed. – When the trowel speed is too high, the cutting force of the trowel blade on the concrete surface is too large. This may cause over-cutting of the concrete surface, destroy the original structure of the concrete, and cause fine cracks or pits on the surface. Especially for concrete whose strength has not yet fully developed, too high a speed may excessively disturb the cement slurry layer on the surface, affecting the final quality of the concrete. – On the contrary, if the trowel speed is too low, the trowel blade will not have enough force on the concrete surface. This will make it impossible to effectively deal with the uneven parts of the concrete surface. For example, on the concrete surface with large stone protrusions or template splicing marks, the trowel at a low speed may not be able to remove these defects, resulting in the ground flatness not meeting the requirements. – Appropriate trowel speed helps to improve the compaction of the concrete surface. When the trowel rotates at a certain speed, the weight of the trowel and the rotation of the blade work together to exert pressure on the concrete surface, so that the particles in the concrete are arranged more closely. For example, in concrete construction with high bearing capacity requirements such as industrial plant floors, the trowel speed is controlled at about 80-120 rpm, which can make the concrete surface better compacted during the troweling process, thereby improving the bearing capacity and wear resistance of the ground. – When the speed is too high, although the surface looks smoother, it may actually make the mortar layer on the concrete surface too loose. Because too high a rotation speed will cause the water in the mortar layer to evaporate too quickly, and excessive rotation will destroy the bonding force between the mortar particles, resulting in insufficient surface compaction, which is prone to quality problems such as sanding and peeling during later use. – If the speed of the trowel is too low, it will not generate enough pressure to compact the concrete surface. This will make the porosity of the concrete surface larger and reduce the compactness of the concrete. Such a concrete surface is easily damaged when there are heavy objects rolling or frequent friction. – A higher trowel speed can make the concrete surface have better gloss. When the speed reaches a certain level, such as 100-150 rpm, the trowel blade can further smooth the mortar layer on the concrete surface during rapid rotation, making the surface more delicate and producing gloss. In some places with high requirements for appearance, such as shopping mall floors and exhibition hall floors, by appropriately increasing the trowel speed, a smooth mirror effect can be created. – However, if the speed is too high, it may cause wavy textures on the concrete surface, affecting the uniformity of gloss. This is because too high a speed will cause the trowel to vibrate during the rotation process, and this vibration is transmitted to the concrete surface, affecting the surface flatness and destroying the uniformity of the gloss. – When the speed is too low, the surface roughness of the concrete is greater and the glossiness is poor. Because the trowel rotating at a low speed cannot fully smooth the microscopic unevenness of the concrete surface, it cannot form a smooth surface, and can only obtain a relatively rough matte effect.