Application of integrated waterproof and thermal insulation system on concrete roof

Source: zhuobao technology author: Chen jin, xiao jianyong

Webex automobil coating: abstract: integration of waterproof insulation board is the use of rigid polyurethane foam "microporous infiltration type" principle, the rigid waterproofing materials, pu cover WenXin material glass fiber mat and cement in the factory of one-time hot pressing composite plate, the plate used on roof, a construction waterproofing and thermal insulation two functions can be realized. This paper takes the roof waterproof and thermal insulation construction of C1 section of logistics base in northeast China as an example, and expounds the application advantage of the integrated system of waterproof and thermal insulation on concrete roof. While ensuring the effect of waterproof and thermal insulation on roof, this system simplifies the structure level, saves the construction period and improves the reliability of the system.

Keywords: roof waterproof and thermal insulation engineering; Integrated waterproof and thermal insulation system; Integrated sheet; PVC waterproof rolling material; Rock wool insulation board

Roof is an important part of the building, which should have two basic functions of waterproof and thermal insulation. It can protect the building from natural wind, rain, snow, solar radiation and winter low temperature. It is directly related to the service life of the building and people's living environment. All the time, the traditional roofing practice, whether it is the normal practice, the traditional inverted practice, or the "sandwich" practice, causes the roof leakage, insulation effect failure and other problems to occur continuously due to unreasonable design and inappropriate material selection. The reason is that the practice of traditional multiple levels of structure, waterproofing and thermal insulation construction, separately between the waterproof layer and insulation layer, waterproof layer and structure layer between water channel, once the waterproof layer break points, the water will from the damaged point into the following levels into the insulation layer structure, insulation heat preservation effect after water could be greatly reduced, the water into the insulation layer and then will continue to flow, when channeling water structure cracks will appear after the leakage, leakage risk is great.

In the production process, the integrated waterproof and thermal insulation board combines the waterproof rolling material and the heat preservation core material together at one time, eliminates the channeling water layer between the waterproof layer and the thermal insulation layer, and simplifies the roof structure layer. One process can realize both waterproof and thermal insulation functions. The integrated waterproof and thermal insulation board adopts wet spreading construction technology. Through the waterproof bonding mortar, it sticks to the foundation surface to eliminate the channeling water layer between the plate and the structure layer, reduce the risk of system leakage and improve the system reliability. In this paper, the application of waterproof and thermal insulation integrated system on concrete roof is introduced by taking the roof project of C1 bid section of northeast China logistics base as an example.

1 project overview

Logistics base in northeast China logistics C1 blocks in liaoning panjin merchant the economic zone bordering on the harbor district, this project is a single grain warehouse construction, building monomer 144.8 m long, 37 m wide, covers an area of 5357.6 ㎡, a total of seven granary, roofing with a total area of 37503.2 ㎡, storability and fireproof rank for the secondary, function for bulk grain storage, guangdong rice.

2 roof system design

The waterproof insulation design of this project USES a layer of polymer cement waterproof coating on the roof base, and then a 50mm thick integrated waterproof and insulation board is wet on the waterproof coating layer. The board is glued on the foundation surface through 5mm thick waterproof bond mortar, as shown in figure 1. The integrated waterproof and thermal insulation board is composed of 1.2mm thick PVC waterproof rolling material, 50mm thick hard foam polyurethane insulation core material and 0.5mm thick cement glass fiber blanket, which are combined into plates through the special process. The waterproof and thermal insulation are integrated, and the functions are mutually reinforcing. One process realizes two functions.

FIG. 1 roof system design

3 system features

The integrated waterproof and thermal insulation system has the following features:

1) one process, two functions: waterproof layer and insulation layer are combined together, unique "sandwich" structure (figure 2), which can solve the problem of waterproof and insulation at one time.

FIG. 2 integrated plate structure for waterproof and thermal insulation

2) optimal type and combination: select high-quality waterproof rolling material PVC waterproof rolling material on the market, hard foam polyurethane is recognized as a good organic heat insulation material, cement based rolling material has good construction performance, and three kinds of high-quality materials are compounded into excellent integrated waterproof and heat insulation system through advanced production process.

3) eliminate water channeling, lasting performance: the combination of waterproof rolling material and temperature preserving core material eliminates water channeling between waterproof rolling material and temperature preserving core material, so the insulation layer is not easy to get water. The temperature preserving core material adopts hard foam polyurethane, which does not absorb water. The waterproof bond mortar is used to stick to the foundation surface (FIG. 3), which eliminates the channeling water between the board and the structure layer, and the system does not channeling water, so that the waterproof and thermal insulation effect lasts for a long time.

Figure 3: after the plate is pasted, lift it up to observe the sticky effect

4) simple construction and time saving: the leveling layer is omitted, the waterproof and thermal insulation process is completed, the structure layer is simplified, the construction is convenient, the board adopts the wet laying process, the wet base surface can be constructed, and the time saving is achieved.

5) energy saving and emission reduction, safety and environmental protection: compared with the traditional roofing system, the material production link, construction and installation link, and the later maintenance link all show the essential characteristics of energy saving and emission reduction, safety and environmental protection.

4 construction technology

The construction process of this project is as follows:

Base cleaning - joint strengthening - spraying polymer cement waterproof coating - board trial - board rewinding - preparing waterproof adhesive mortar - scraping waterproof adhesive mortar - sheet laying - roller rolling - lap joint long edge welding - plate vibration - lap joint short edge welding - joint processing - weld inspection - roof acceptance

4.1 grassroots cleaning

Clear the base debris, loose concrete, floatation, the base convex concrete chiseling.

4.2 node strengthening

All internal angles of the roof are rounded with a radius of 25mm by using the plug king. The joint part is strengthened with double-sided self-adhesive waterproof rolling material. The width plane and facade of the joint part are not less than 250mm. See figure 4.

FIG. 4 strengthened nodes in parapet wall

4.3 polymer cement waterproof coating

A layer of polymer cement waterproof coating is sprayed on the base surface. The coating has the following functions:

(1) defects such as micro-cracks in the base can be repaired to improve the waterproof performance of the structure;

(2) improve the bond strength between waterproof bonded mortar and base surface;

(3) after spraying, scratch the waterproof adhesive mortar on the base surface to prevent the mortar from losing water too quickly due to the water absorption of the base, so as to guarantee the bonding effect between the board and the bonded mortar.

4.4 panel trial shop

Pre-lay the board on the base, determine the placement of the board, and prevent the plate from spreading out in a wrong way after scraping the mortar. See figure 5.

FIG. 5 panel test

4.5 sheet rollback

Before scraping waterproof adhesive mortar, roll back the boards that have been tried out, and scratch waterproof adhesive mortar on the foundation surface that is empty after the boards are rolled back. See figure 6.

Figure 6 sheet rollback

4.6 prepare waterproof bonded mortar

The waterproof bond mortar is distributed in the mixing barrel. Water is added before powder is added to make it easy to mix evenly. See figure 7.

Figure 7. Preparation of waterproof bonded mortar

4.7 scratch waterproof adhesive mortar

Use the tooth space not less than 10mm tooth rake to scratch waterproof adhesive mortar, ensure that the thickness of waterproof bonded mortar is not less than 5mm, waterproof bonded mortar thickness should be painted evenly. The waterproof bond mortar shall be at least 5mm thick, which can ensure that the board and the base surface are fully adhered, and eliminate the channeling water between the board and the base surface. See figure 8.

Figure 8. Scratch waterproof bonded mortar

4.8 spreading the sheet

After the waterproof bonded mortar is scraped, spread the rolled back plate on the mortar, and then scratch the waterproof bonded mortar to cover the plate. See figure 9.

FIG. 9 spreading sheet

4.9 roller crushing

When a plate is finished, the roller is used to vibrate and roll it immediately, and the air under the plate is discharged to make the board more tightly bond with the base surface. The exhaust is from the middle to both sides. See figure 10.

FIG. 10 roller crushing

Long side welding of lap joint

Long side use crawling welding, lap side width is 80mm, effective welding width is not less than 25mm. See figure 11.

Fig.11 long side welding

4.11 plate vibration

After the long edge of the plate is welded, the plate is vibrated with the plate vibrator to make the plate and the base surface fully stick, and the bond mortar is squeezed into the plate seam to seal the plate seam.

Short lap welding

The short side is welded bilaterally with the hand welding gun, with the lap side width of 150mm and the effective single side seam width of no less than 25mm. See figure 12.

FIG. 12 short-side welding

4.13 node processing

After the large surface construction, PVC waterproof rolling material was used to treat the joints such as the water-falling mouth, parapet wall and deformation joint, and silicone weather resistant sealant was used to seal the joints. The specific construction method was shown in the details.

4.14 weld inspection

Use the crochet needle to inspect the welding seam, and repair it immediately if there is leakage welding or damage, so as to ensure the integrity of the whole waterproof layer. See figure 13.

Figure 13 weld inspection

4.15 roof acceptance

5 detailed node practices

Most of the detail joints are in the places where deformation is concentrated, which is prone to cracking and damage, and most of the joints are complex, with high requirements for construction and operation technology, which is the weak link in the waterproof project. Therefore, whether the construction of the waterproof details is reasonable or not is the key point of the waterproof project. Several important methods of waterproof construction in this project are listed below.

5.1 the parapet

The parapet wall is wet with 500mm wide double-sided self-adhesive waterproof rolling material, 250mm on the facade wall and 250mm on the plane. Use polymer cement to paste polypropylene cloth to cover the self-adhesive film on the facade coil as the separation, and paste 100mm above the mouth of the facade coil. After the rock wool fire isolation belt is pasted, PVC waterproof rolling material is pasted on the rock wool board under the parapet wall. The PVC waterproof rolling material shall be pasted on the parapet wall for at least 250mm, and glued to the daughter wall. See figure 14.

Figure 14. Parapet node processing

5.2 the water mouth

First of all, use the plug king to fill the floor gap chassis and gap between the base, and the flat disk circle into a circular arc. Then use polymer cement waterproof coating to paste double-side self-adhesive waterproof rolling material to make waterproof strengthening layer, the width shall not be less than 250mm around the water inlet, and use polymer cement waterproof coating to seal the edge of rolling material. The waterproof rolling material of parapet wall shall be pasted and pasted on the waterproof rolling material of parapet wall (the falling water shall be in the drainage ditch of parapet wall), and then the PVC waterproof rolling material shall be welded around the landing port. The rolling material shall be not less than 200mm deep into the landing port. See figure 15.

FIG. 15 processing of nodal points at the inlet

5.3 deformation cracks

Wet a 500mm wide double-sided self-adhesive waterproof rolling material on the inner corner of the deformation seam, 250mm on the vertical wall and 250mm on the plane. Use polymer cement to paste polypropylene cloth to cover the self-adhesive tape on the facade coil as the separation, and paste 100mm above the mouth of the facade self-adhesive tape. After the rock wool fire separation belt is pasted, the PVC waterproof rolling material is pasted on the rock wool board at the bottom of the deformation seam wall. The PVC waterproof rolling material is turned over to the top of the deformation seam and glued on the wall. Fill the rock wool in the deformation seam. Weld a piece of PVC waterproof rolling material on the top of the seam first, then fill the foam rod, and then cover the deformation seam with PVC waterproof rolling material on the top and weld the rolling seam. See figure 16.

FIG. 16 deformed joint processing

6 conclusion

Northeast China logistics integration of logistics base bid C1 granary roofing waterproof thermal insulation system, completed by the middle of October 2017, roofing with a total area of 37503.2 ㎡, construction lasted only two months, and during the period of construction after two heavy rain, the rain check has finished working face roof without funnelled, which fully embodies the integration of waterproof thermal insulation system of unique advantages. Waterproof and thermal insulation are combined together, and one process has two functions. The process is simple, and the wet laying construction process has low requirements on the base and is less affected by the weather. Integration of waterproof insulation board after one-time extrusion compound, eliminates the waterproofing materials and between WenXin material layer, plate wet spread through the waterproof binding mortar with the base surface, eliminate between the plate and the base layer, the system is not running water, thermal insulation layer is not bibulous, guarantee the function of roof waterproofing and insulation. The popularization and application of integrated waterproof and thermal insulation system will bring breakthrough progress to solve the problem of roof waterproof and thermal insulation.