Just a few steps to teach you how to operate a ride-on trowel

The technical construction of laser leveling machine is a brand-new design concept. The application of leveling machine has become a popular trend in the modern concrete industry. However, what is the technical solution of laser leveling machine? Let's introduce it in detail below. 1. Requirements for concrete ❶ Concrete must be produced by commercial concrete production plants, transported or pumped to the floor project site. ❷ Concrete specifications: C25~C30 concrete, the 28-day strength is not less than 25MPa, according to the design requirements. ❸ Water-cement ratio: no greater than 1. Do not add water at will during the feeding process. ❹ Cement: Use ordinary Portland cement not less than the grade. ❺ Aggregate: Well-graded aggregates should be used. Use crushed granite or pebbles as coarse aggregate, with the maximum diameter not larger than 25mm. Clean river sand is used as fine aggregate, and the fineness modulus is appropriate. ❻ Concrete mix ratio: cement dosage should not be less than 350Kg/m3. In order to avoid surface quality problems, the sand rate should be controlled at 35%~40% ❼ Concrete slump: 14+2cm, maximum 16cm ❽ Setting time: The initial setting time should be controlled at 3-5 hours. 2. Construction coordination requirements ❶ The concrete feeding speed should be determined according to the ground thickness and pouring area. The minimum hourly feeding speed should be determined. For a floor with a thickness of 200 mm, if the one-time pouring width reaches 40 meters, the minimum feeding speed should reach 40 cubic meters per hour. Otherwise, cold joint problems will occur and the quality of the ground construction will be affected. ❷ Manual cooperation requires workers to remove the concrete delivered to the floor as soon as possible and roughly level it. In addition, manual leveling is required for areas around the formwork, walls, columns, trenches, equipment foundations, floor drains or pipelines that cannot be leveled. Generally, 3-4 workers are required to cooperate with the construction (provided by Party A). ❸ Other precautions: To ensure the flatness of the ground, please note: ① The slump of the concrete delivered to the floor must be consistent each time. ② Ensure that the concrete supply speed reaches 40 cubic meters per hour or above, and the initial setting time of each batch of concrete must be consistent. ③ Ensure that the formwork elevation is accurate and cannot be disturbed during construction. ④Environmental cooperation. The newly constructed concrete floor should not be exposed to sunlight, wind, rain and other environments that are detrimental to the health of concrete. ❹ Other requirements: A. In order to avoid random cracks on the floor, shrinkage joints should be cut as early as possible (within 24 hours). B. While the laser leveling machine is being constructed, there must be no welding machines or reflective objects (such as glass windows) on site. C. The foundation must reach a certain hardness to ensure that the laser leveler does not collapse when operating on the ground. D. The height of the ground in the factory building is calibrated by Party A. The points must be evenly distributed and there must be no error in level. E. Concrete pouring must be carried out according to the requirements of Party B's technical personnel.

    The problem of sudden deviation in the leveling accuracy of the concrete Laser Leveling during the construction process is an extremely urgent situation. The following is a systematic guide for troubleshooting, calibration and repair aimed at helping you resume construction quickly. When there is a sudden deviation in accuracy, please follow the principle of "from the outside to the inside and from the easy to the difficult" to conduct a systematic investigation. Check the laser signal source Stability: Immediately check whether the tripod of the laser emitter has been knocked over or settled by personnel or equipment. Battery power: Make sure the laser is fully charged. Low battery power may cause unstable beam. Cleanliness: Quickly check if there are any mud spots or dust on the light-emitting lens of the laser emitter, and clean it with special lens cleaning paper. Inspect the body of the leveling machine Receiver rod: Check whether the mast on which the receiver is installed has been bent or loosened. Receiver cleaning: Check if the surface of the receiver sensor is contaminated by cement slurry or dust, and clean it immediately. Scraper and flattening head: Check whether the bottom plate of the flattening head and the scraper have severe wear or concrete accumulation, as this can cause physical scratches and affect the perception accuracy. If the initial inspection does not solve the problem, please perform the following in-depth operations. 1. Calibration verification of the laser system Manual rotation test: Manually and slowly rotate the laser emitter 360 degrees to observe whether the signals of the leveler receiver are consistent and stable in all directions. If there is a continuous deviation in a certain direction, it might be that the transmitter's reference is inaccurate. Check the reference height: Use a tower ruler or steel tape measure to measure whether the reference height set by the laser emitter is consistent with the actual height of the ground control point, and eliminate errors in the reference setting. 2. Mechanical inspection of the leveling machine body Hydraulic system pressure: Check whether the hydraulic pressure of the lifting mechanism is normal and stable. Insufficient pressure can cause the flat head to "sink" in the concrete, resulting in overly deep scratches. Sensor and actuator connection: Check whether the mechanical or electrical connection between the receiver signal and the hydraulic valve is loose or damaged. Try to conduct a "manual/automatic" switching test. In the automatic mode, slightly cover the receiver manually and observe whether the flat head responds quickly to rise and fall. If there is no response or the response is slow, it indicates a fault in the signal transmission or hydraulic control system. 3. Perform rapid on-site calibration (key step) Most modern laser screeners are equipped with "quick calibration" or "learning" functions. Please refer to the manual of your equipment (such as YZ30-4E from Shandong Vanse Technology) for operation. The general process is as follows: Enter calibration mode: Go to the calibration menu on the control panel. Locate the high and low points: Turn on the Leveling to a known reference plane (or have the laser emitter sweep out a plane), and move the receivers to a known "high point" (with the display bar at the top) and a "low point" (with the display bar at the bottom) respectively. Data collection: Confirm the position at each point and let the machine record the corresponding relationship between the Angle of the laser signal received at this time and the height of the flattening head. Complete and test: Save the calibration data and exit the menu. Move the machine on the reference plane and observe whether it can be stably maintained at the "zero position" (with the green light constantly on). If obvious mechanical faults such as mast bending or hydraulic cylinder leakage are found, use should be stopped immediately and maintenance personnel should be contacted. Electronic system failure: If it is highly suspected after investigation that the fault lies within the control mainboard, receiver or laser transmitter, the "replacement method" should be adopted. Replacing the spare laser transmitter or receiver for testing is the fastest way to locate the source of the fault. Activate the backup plan: When the fault cannot be immediately eliminated and the construction task is urgent, it can be used as a temporary measure to switch to manual mode. Relying on the experience of skilled operators, the current section construction can be completed, and the equipment can be moved aside for maintenance to avoid prolonged downtime. Stop: Immediately shut down the machine to prevent the defect from expanding. Look: Conduct a quick visual inspection of the laser, receiver, and flattening head for any obvious abnormalities. Clean: Clean all optical and mechanical components. Check: Verify the laser reference and the response of the leveling machine. Calibration: Carry out on-site rapid calibration procedures. Replace: Conduct replacement tests using spare parts. If the above steps are ineffective, contact the technical support of the equipment supplier immediately. Following this process quickly and calmly can minimize downtime to the greatest extent and ensure the quality and efficiency of construction. Regular preventive maintenance of equipment is the best way to avoid such unexpected problems.   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.    

  Relationship with the direction of principal stress: The main function of the steel mesh is to bear the tensile force in the concrete structure. When the structure is stressed, the principal stress will be generated inside the concrete. The laying direction of the steel mesh should be consistent with the principal stress direction as much as possible, so that the tensile strength of the steel bars can be fully exerted and the bearing capacity of the structure can be effectively improved. For example, in a one-way slab, the load is mainly transmitted along the short span direction, and the direction of the principal tensile stress is also roughly along the short span direction. Therefore, the bottom steel mesh is usually arranged along the short span direction to resist the tensile force. Two-way stress situation: For a two-way slab, the spans in both directions are similar, and both bear a large load. The steel mesh in both directions must bear tensile force. At this time, the steel mesh should be arranged in a certain proportion according to the force size in the two directions, and is generally laid perpendicular to each other, so that the structure can have sufficient bearing capacity and good deformation performance in both directions. Control of crack direction: A reasonable laying direction of the steel mesh can guide the development direction of the crack, so that it develops in the direction with less influence on the structural force. For example, in concrete pavement, transverse reinforcement can limit the development of longitudinal cracks, while longitudinal reinforcement can restrain transverse cracks, thereby improving the integrity and durability of the pavement. Improving crack resistance: When the steel mesh is laid along the direction where cracks may occur, it can play a "bridge" role after the concrete cracks, withstand the tension on both sides of the cracks, and prevent the cracks from further expanding. For example, in the wall of a hydraulic structure, the horizontal and vertical steel meshes work together to effectively improve the wall's ability to resist cracks caused by factors such as temperature changes and concrete shrinkage. Protecting steel bars: The correct laying direction of the steel mesh helps to ensure the protective effect of concrete on the steel bars. The steel bars are wrapped in concrete to prevent them from rusting and corroding when exposed to the external environment. If the steel mesh is laid improperly, resulting in deviation in the position of the steel bars or uneven thickness of the protective layer, the steel bars are prone to rust under the action of external corrosive media, thereby reducing the durability of the structure. For example, in the basement structure of a building, the laying of the steel mesh should ensure that there is a sufficient and uniform concrete protective layer to prevent groundwater from corroding the steel bars. Uniform stress: Reasonable laying direction makes the steel mesh evenly stressed in the structure, avoiding premature destruction of concrete due to local stress concentration, thereby providing a stable protective environment for the steel bars and extending the service life of the structure. In short, the laying direction of the steel mesh is an important factor affecting the performance of the building structure. During the construction process, the laying direction of the steel mesh must be reasonably determined according to the stress characteristics and design requirements of the structure to ensure the safety, applicability and durability of the building structure.