In order to ensure the construction quality of concrete floor, more and more construction units now choose to use precision laser leveling machines to lay concrete floor. However, in the actual construction process, due to the inadequate cooperation of some enterprises in construction, or not strictly following the regulations to operate correctly, the quality of concrete floor construction is sometimes poor. In order to avoid such a situation from happening again, our company has made a detailed description of some matters related to the construction cooperation during the construction of the laser leveling machine. We hope that the relevant construction personnel will keep it in mind.
❖Wall line laying and leveling: Since the laser leveling machine cannot touch the wall, manual leveling is required within 200mm from the wall, so it is necessary to lay out the line as a reference for manual leveling. At the same time, set 2 to 3 leveling base points (ground design elevation, i.e. ±0.0) that are not disturbed during the construction period for the laser leveling machine to use at one time, and require good mutual visibility. Leveling point accuracy ±1mm.
❖Set templates (steel templates, the position is determined according to design requirements) around the columns to form separation seams. The elevation of the top surface of the template should be controlled within +0mm and -2mm to avoid affecting the flatness of the joints.
❖Installing construction joint formwork: Install the construction joint template along the range to be poured on the day (steel template is recommended), and the template should reserve holes with a spacing of 300mm for the insertion of the force transmission rod. The elevation of the top surface of the template should be controlled within +0mm and -2mm to avoid large deviations in the flatness of the joints of different bins.
❖Laser transmitter installation: It is planned to be installed on the column. The specific location should be set at a better location according to the amount of paving on the day. If it cannot be installed on the column, it should be installed on a special tripod.
❖In order to ensure the quality of concrete floor paving, each group needs to arrange 10 to 12 workers to cooperate to flatten the surface of the concrete spread on the ground so that the pile is slightly higher than the design elevation (about 20 to 30mm). At the same time, for the parts near the wall, exposed pipelines and the surrounding of the formwork, two workers are arranged to manually smooth the concrete material about 20~30cm away from the wall (formwork) (using a 2m scraper with an iron trowel). The workers responsible for smoothing the edges must be trained and skilled plasterers. These workers must obey the command and follow the arrangement to ensure the quality of construction.
❖ Since the thickness of the concrete reaches 200mm, and because of the installation of steel mesh, in order to ensure the compaction of the concrete, this project needs to arrange a vibrating rod to cooperate with the vibration. At the same time, in order to ensure that the protective layer of the steel mesh reaches the design requirement of thickness (70mm), it is necessary to arrange for manual lifting of the steel mesh and pad the support block in the range to be paved in advance.
❖ The width of the concrete material paved on the platform each time is required to be no more than 5m, and the length is based on the formwork boundary. The construction direction is from left to right (along the short side direction) and from front to back (along the long side direction). The recommended daily paving volume is 1200~1500㎡. Calculated based on 12 hours of working time per day, the feed rate is required to be 30 to 40m³.
❖Others: To ensure the flatness of the ground, special attention should be paid during the construction of the laser leveling machine: the slump of the concrete delivered to the platform each time must be consistent; the concrete feed rate must reach 40m. per hour or more, and the initial setting time of each batch of concrete must be consistent; the template elevation must be accurate and cannot be disturbed during construction; environmental coordination. The newly constructed concrete floor cannot be exposed to sunlight, wind, rain and other environments that are unfavorable to the curing of concrete.
Special reminder: In order to make the laser leveling machine give full play to its inherent functions and ensure the construction quality and efficiency of the concrete floor, in addition to mastering the above-mentioned construction coordination precautions, there are many details that need to be paid attention to. Please look forward to the subsequent updates and sharing of this site.