4.4.1. Introduction to technology.
The geothermal pipe and polystyrene board in the floor have an impact on the cracking of the ground surface layer, and this practice proposes the construction measures of the geothermal heating floor ground twice pouring and molding, so as to minimize the cracking of the geothermal ground, and the practice proves that the measures taken are positive and effective, and the good quality objectives have been achieved.
The main reason for the ground crack is the shrinkage and deformation of the concrete, and the floor floor can be reduced by pouring the concrete surface layer in two times, and the reasons are: first, the first concrete is used to fix the geothermal pipe, so that the geothermal pipe will not float up when the surface layer concrete is poured, and the effective thickness of the concrete on the upper part of the geothermal pipe is guaranteed, so that the surface layer concrete does not cause the cracks in the surface layer concrete because of the thickness reduction;Second, the first concrete to reach a certain strength can increase the firmness of the base layer and reduce the base disturbance caused by the weakness of the polystyrene insulation board. So as to achieve the purpose of reducing the cracking of the concrete surface layer.
4.4.2 technical points.
1) Construction of moisture-proof layer and thermal insulation layer.
Use a long-handled brush to dip the prepared paint in the order of first high and then low, first far and then near, and the coating film should be uniform. According to the design materials, lay the thermal insulation layer, and the thermal insulation layer should be laid flat and tightly lapped. Except for the plastic nails that fix the heating tube to the insulation, there must be no other damage.
2) Installation and laying of geothermal pipes in manifolds.
The water separator and water collector are made of copper materials, and the color of the surface plating connection should be uniform, and the plating layer should be firm and there should be no defects of deplating. The water collector should be installed before the heating pipe is laid. When installed horizontally, the water separator is on the top and the water collector is on the bottom, and the center distance is 200mm;The center of the water collector should not be less than 300mm from the ground.
The geothermal pipe is a PE-RT pipe with a nominal outer diameter of 20 mm and a wall thickness of not less than 23mm。Design Stress 334mpa。The arrangement of geothermal pipes in the project is mainly rotary transformation, and some of them are in-line type. The bending radius of the plastic pipe is 6 times the outer diameter of the tube. Geothermal pipes buried in the infill layer should not have joints. When the geothermal pipe passes through the expansion joint, a flexible casing with a length of not less than 200mm should be provided at the expansion joint. Geothermal pipes are not arranged under sanitary ware.
3) Pouring concrete.
To prevent cracking, concrete is poured in two parts, at least 1 day apart. The surface layer is made of commercial concrete, the slump is controlled between 120 and 20mm, and the water-cement ratio should not be greater than 050。Since the infill layer construction has covered the geothermal pipes, the surface layer pouring can not consider the damage to the geothermal pipes.
According to the pop-up mark line of the height of the ground layer of the building, make ash cakes around the ground, with a spacing of 15m-2m plus punching bars, to make a 1% drainage slope around the bathroom floor drain.
Paving fine stone concrete: fine stone concrete to the design elevation, then scraped with a long bar, vibrating and compacting, the surface collapse should be leveled with fine stone concrete, and then scraped once with a long scraper, and rubbed flat with a wooden trowel.
In order to reduce the cracking of the floor heating ground, uninterrupted expansion joints should be left at the junction with vertical components such as internal and external walls and columns, and the filling materials of the expansion joints should be connected by lap joints, and the lap width should not be less than 10mm;The expansion joint filling material should have reliable fixing measures with the wall and column, and the connection with the ground insulation layer should be tight, and the width of the expansion joint should not be less than 10mm. When the ground area exceeds 30m2 or the side length exceeds 6m, expansion joints should be set at a distance of no more than 6m, and the width of the expansion joints should not be less than 8mm. The expansion joint filling material is made of high-foam polyethylene foam.
The expansion joint should go from the upper edge of the insulation layer to the upper edge of the infill layer. The expansion joint at the entrance of the house is made of 1cm wide wood.
strips are separated, and when the concrete is poured, footprints can be left on the ground surface layer but do not sink, and the wooden strips are taken out, 2
After the week, fill the caulk with cement mortar.
5) Concrete calendering.
After the concrete pouring is completed, the scraper is used to scrape flat, and then wait until the concrete is basically finalized, and no obvious footprints will be formed when stepping on it, while sprinkling dry cement, sprinkling water, and collecting light, and closing the surface continuously for 4 to 5 times until the concrete surface is completely finalized. The corners and parts that cannot be wiped by machinery are manually rubbed and calendered with machinery. If there are pits or stones on the surface of the plate, it is necessary to shovel the hair, remove the slurry and trim it in time.
6) Concrete curing.
The ground pouring is completed, and the plastic film covered with water is used for continuous maintenance until the final setting before the initial setting.