With the development of urban underground space, the number of underground utility tunnel construction projects is increasing. Pipe gallery dedicated HDPE self-adhesive film waterproofing membrane is a special high-density polyethylene film as the substrate, the substrate covered with self-adhesive layer and isolation layer, has many advantages:

1. The self-adhesive layer has strong adhesion and can be attached to the base surface of the main structure without empty drum or water channeling.

2. The coil and the base layer are empty and unbonded. The settlement deformation of the base layer will not affect its waterproof function.

3. Excellent impact resistance and puncture resistance.

4. Strong chemical resistance. It has good resistance to alkaline water from concrete, and has anti-mold and anti-corrosion properties.

4. Can be wet shop, low requirements for the base. It is not affected by weather and moisture at the base level, and can effectively ensure the construction period and quality.

5. No surface treatment, no need to base oil or hot air drying wet base, no volatile substances.

6. Cold construction, safe and fast construction, to ensure the construction efficiency.

At the same time, according to the construction environment and requirements, HDPE self-adhesive film sand-coated waterproofing membrane can be used, that is, a layer of sand surface layer is compounded on the surface of the coating layer, and the sand surface can be used as an isolation layer to prevent the adhesive layer from sticking to the foot, and can well protect the waterproofing membrane.

HDPE self-adhesive film waterproofing membrane construction technology points:

1) The single-sided pre-laid waterproof coiled material shall be laid on the floor and the side wall after the reinforcement layer is laid at the yin and yang corners. The construction sequence shall be the bottom plate before the side wall. The bottom plate is laid longitudinally, each stage is from one side to the other (e. g. west to east), and the side wall is laid from bottom to top. The side close to the floor cushion and the retaining pile is the adhesive surface, and the surface close to the outer surface of the structural concrete is the isolated surface (adhesive surface).

 

 

2) The waterproof layer of the side wall is mechanically fixed on the surface of the maintenance cavity. The fixing point is 2cm away from the edge of the coil, the nail distance is not more than 50cm, and the nail length is not less than 27mm. The waterproof layer is firmly fixed on the surface of the base layer with a gasket. The gasket diameter is not less than 2cm, and the thickness is not less than 1.0mm. During facade construction, within 10-20mm from the coil edge at the self-adhesive edge position, mechanical fixing shall be carried out every 400-600mm, and the fixing position shall be completely covered by rolling.

3) The long side of the coiled material shall be overlapped by self-adhesive edge, with an overlapping width of 70mm, and the short side shall be overlapped by 80mm wide adhesive tape. The overlapping areas at the ends of the coiled material shall be staggered with each other, and the nail holes shall be covered, and the upper width shall be pressed down for overlapping.

4) After laying the waterproof layer of the bottom plate, before binding the steel bars, remove the isolation membrane of the coiled material, and timely apply a 50mm thick fine stone waterproof concrete protective layer with the same label as the bottom plate. Temporary protective measures shall be taken for the side wall waterproof layer to ensure that the waterproof layer is not damaged.

5) The damaged part of the waterproof layer shall be pasted and repaired with double-sided materials of the same material. The patch shall be fully stood on the damaged part, and the minimum distance between the patch and the damaged edge shall not be less than 10cm.

6) The end of the coil and the overlap of the incision shall be sealed with special tape. The concrete shall be cast and tamped within 40 days after the waterproof layer is installed.

7) when laying double-layer coiled materials, the long side joints of the upper and lower coiled materials shall be staggered by 1/3~1/2 width, the short side joints of the upper and lower coiled materials shall be staggered by more than 1m, and the lap joints of the reinforced coiled materials and the lap joints of the waterproof layer shall be staggered by 0.3m.

8) The isolation membrane of HDPE waterproofing membrane, whether it is the bottom layer or the side wall, should be torn off while constructing, so as not to be stained with waste, dust, etc., which will affect the bonding effect or fail to bond.

9) After the construction of a waterproof coiled material construction section is completed, it shall be reported to the supervisor for acceptance in time. After passing the acceptance, enter the next process; if the acceptance is unqualified, repair the unqualified parts immediately, and only after the requirements are met and the acceptance is qualified can the next construction be carried out.