(1.National Building Materials Industry Building Waterproof Materials Product Quality Supervision, Inspection and Testing Center, Suzhou 215008, Jiangsu, China; 2 Beijing Zhuobao Waterproofing Engineering Co., Ltd., Beijing 100025) Rubber bitumen waterproofing membranes) principle and verification test results of pre-paste anti-sticking technology As well as engineering application technology, it is also pointed out that the application of this technology can achieve the effects of energy saving, material saving, and environmental protection.
At present, in various types of ordinary civil-industrial construction and tunnels and other waterproofing projects, the external defense inlaying method is widely used, that is, pre-laying waterproofing membranes prior to the placement of structural concrete. As the subsequent concrete construction process may cause some damage to the waterproof layer, and traditional materials cannot be bonded with the post-cast concrete, a hydrophobic layer exists between the waterproof layer and the concrete structure layer, and the water passes through the waterproof layer. After the layer, it will seep into the room where the concrete is weak.
To fundamentally solve the problem of leakage, the waterproof layer must be firmly bonded to the post-cast concrete. Zhuobao's BAC waterproofing membrane (hereinafter referred to as "BAC membrane") developed by Zhuobao Company is a wet-laid compound double-sided self-adhesive rubber asphalt waterproofing membrane with good adhesion to post-cast concrete. It can be applied to the basement, exterior wall, tunnels and other external defenses and in-spot methods. It can solve the problem of drowning caused by the non-bonding between traditional waterproofing membranes and structural concrete, thus fundamentally improving the reliability of waterproofing. .
When applying pre-coated anti-adhesive webs, the bonding properties and anti-water-repelling conditions of the web and the post-cast concrete in different conditions need to be considered. The National Building Materials Industry Building Waterproof Materials Product Quality Supervision, Inspection and Testing Center has set up a special task group to compare the bonding performance of BAC coils when using this construction method to provide guidance for the use of materials. The test method simulates the environment and methods of actual project construction.
1 Test process and data analysis The study is divided into BAC and grass-roots under the standard curing conditions of the shear, peeling performance, the membrane and the grass-roots in the flooding conservation conditions, shear, peeling performance, BAC membrane in acid, alkali, After the salt solution is processed, the membrane has four parts of the water repellency of the adhesive surface after the water surface of the substrate is subjected to water pressure.
The test uses a 3mm thick BAC web (polyester tire), and the top and bottom surfaces of the web can be wet-bonded. For each set of 5 test pieces, the test result is taken as the arithmetic average of the test results of the five test pieces.
1.1 Shear and Peel Performance under Standard Conditions Standard curing conditions refer to cement curing conditions of temperature (20±1) 4 and relative humidity of 95% or more. The width of the coil shearing and bonding performance test piece is 70mm, the bonding area is 70mmx75mm, the length of the cement sand and zinc palm is 0mmx220mmx (30~40)mm, and the cement concrete block size is 70mmx220mmx (50~60)mm. Rice uses Portland cement with a strength rating of 42.5.
Shear and peel strength were measured using an electronic tensile tester. Test Temperature This test simulates the shear and peeling effects of the adhesive surface that may occur in a practical project.
BAC Coil's Bonding Performance to Post-placed Concrete Under Normal Conditions C30 concrete was poured on a BAC coil and then tapped with a vibratory table, placed 24 at 234 and then cured under standard curing conditions. The shear and peel strengths were tested after 7d and 28d respectively. The results are shown in Table 1. Table 1 Bonding performance of BAC coils under normal conditions with post-cast concrete Curing time/d Peel strength (/m) Shear strength (/m) After the shear test of the post-concrete, the result was that the coil was broken. The test results show that the bonding of BAC coils to post-cast concrete under normal conditions is very good.
BAC Coated with Dust After Adhesion with Post-Concrete Concrete Sand was spread on the flat BAC coiled surface and kept for 7 days. Then the floating sand was rinsed with water. Then the coil was placed flat and the C30 concrete was placed. On the dust surface of the coil, use a vibrating table to shake it, place 24 at 234 and then cure under standard curing conditions. The shear and peel strengths were tested after curing for 7d and 28d respectively. The results are shown in Table 2. Table 2 Adhesion properties of BAC membranes with post-concrete concrete Curing time/d Peel strength (/m) Shear strength (/m) ) The 28d shear strength test of the BAC coiled with dust and post-concrete concrete resulted in the coil being broken. The test results show that the post-concrete cement has good adhesion with the dust-coated sheet on the bonding surface.
Bonding of cement powder on the surface of BAC membrane to post-concrete concrete Cement grade 32.5 cement powder is spread on the bonded surface of the flat BAC coil for 7 days, then the surface cement powder is rinsed with water, and then The coils were placed flat. The C30 concrete was poured on the cement powder surface of the coil, and was shaken with a vibration table. 24 was placed at 234 and then cured under standard curing conditions. The shearing and peeling strengths were tested after curing for 7 and 28 days respectively. The results are shown in Table 3. Table 3 Adhesion properties of concrete coated with cast-in-place concrete after curing on BAC membrane surface Curing time/d Peel strength (/m) Shear strength ( /m) The test results show that the post-concrete cement adheres well to the BAC with cement powder on the bonding surface.
Through the above experiments, it can also be found that the longer the curing time is, the better the bonding effect is.
1.2 Shearing and stripping performance under water immersion Condition The immersion water curing condition refers to immersing the test piece in water for maintenance. The specific conditions are water temperature (23±2)4 and time of 28 days. Other test methods are the same as the standard curing conditions.
This test is mainly used to evaluate the influence of submerged water on the shearing and peeling performance of the adhesive surface in the construction surface when the underground water level cannot be reduced. ) BAC coil under normal conditions and post-concrete adhesion properties of the test: the C30 concrete poured on the coil, and then use the vibration Taiwan vibration 2006.3 China building waterproof, 23 / place 24 1 and then immersed in water curing. Shear and peel strengths were tested after curing for 28 days. ) Bonding performance of BAC coiled material to post-concrete concrete: Sand is sprinkled on the cohesive surface of the coiled sheet for 7 days. Then the floated sand is rinsed with water, and then the coil is laid flat. The concrete was poured on the dust surface of the coil and was shaken with a vibrating table, placed at 23/under 241 and submerged in water for curing. Shear and peel strengths were tested after curing for 28 days.
3) Bonding performance test of BAC membrane surface with cement powder and post-concrete concrete: Spread cement powder with strength grade 32.5 on the flat surface of the coiled material and keep it for 7 days, then rinse the surface with cement powder. Next, the coils were placed flat, and the C30 concrete was poured on the cement powder surface of the coils, and was shaken with a vibrating table, placed at 23/24 hours, and then immersed in water for curing. Shear and peel strengths were tested after curing for 28 days.
The results of the above three tests are shown in Table 4. The tests showed that: 1) The post-concrete concrete is bonded to the BAC coils under normal conditions and the BAC coiled with dust on the bonding surface, and is soaked in water even on the second day. , Still good adhesion; 2) The post-concrete and BAC membrane with cement powder on the bonding surface are poured and glued and then soaked. The bonding effect is not good.
Table 4 Bonding properties of post-cast concrete and BAC coils under different conditions (water immersion curing 28d) Test peel strength (n/%) Shear strength (n/%) Bonding and bonding with BAC coils under normal conditions Dust-soaked BAC Coated material is placed on the bonding and bonding surface and cement powder is placed on the material. Cohesion of the material can be found through the above test. The shear strength and peel strength of the BAC material after water curing are lower than the standard curing conditions. As far as possible in the project, do not immerse the coils in the initial stage of the bonding process in water, and soak the water for a long time until the cement hydration reaction is substantially completed.
1.3 Performance after acid, alkali and salt solution treatment The performance of acid, alkali and salt solution after treatment includes the material property change of BAC coil itself and the shear stripping performance of post-concrete concrete.
The acid solution is a mass fraction of 2-H2SO4 solution, the alkali solution is a saturated Ca(OH)2 solution, and the salt solution is a mass fraction of 10-NaCl solution.
The BA5 coils were cut into test pieces and immersed in acid, alkali and salt solutions for 2*d. After being washed, tensile properties were tested. The dimensions of the coiled specimens are 150mm x 25mm, tensile speed 50mm/min, clamp spacing 75mm, and the test results are shown in Table 5. Table 5 BAC web solution after treatment Tensile properties change items Standard conditions Acid treatment Alkali treatment Salt treatment Tensile force Horizontal direction Rate / - Longitudinal transverse test results show that: After the solution treatment, the longitudinal properties of the coil material change is not obvious, the transverse elongation increases.
2) Shear and peeling properties between webs BAC webs were overlapped on the upper and lower surfaces, placed 1 and then immersed in the solution for 28 days. After being washed, the shearing and peeling performance tests were performed. The tensile speed was 250 mm/min. See the test results. Table 6. Table) Changes in Shear and Peel Performance Between Coil and Coil after Treatment of BAC Coil Solution Standard Conditions Acid Treatment Alkali Treatment Salt Treatment Peel Strength パ N/mm) Shear Strength パ N/mm) Test Results There was no change in the shear and peel properties between the two, indicating that the cohesive properties of the coiled solution after soaking were good.
3) Shear and peeling performance of post-concrete concrete C30 concrete was poured on the BAC membrane, and then vibrated with a vibrating table, placed at 23/24 for 24 hours, then immersed in the solution for 28 days, taken out and washed, and tested for shearing and peeling, respectively. strength. The exposed concrete surface of the acid-treated specimen was sealed with epoxy resin to prevent acid from reacting with the concrete.
The test results are shown in Table 7. The results of the above test were compared with those of the post-concrete concrete in Table 4 “Bacco Coil and Post-Concrete Adhesive Performance Items Treated after Treatment with Normal Condition 7 Solution Acid Treated Alkali Treated Salt Treatment Peel Strength/(N/ Comparison of the results of the immersion test of BAC coils under shear strength パN/mm). After the dipping solution treatment, the bond strength between the post-concrete concrete and the coil is reduced, but it still has better Bonding properties. 1.4 Adhesion surface anti-water repellency performance On the adhering surface of the coil, the impermeability test block of the formed concrete was drilled, and a hole with a diameter of 10 mm was opened in the middle of the coil. After the construction of the simulation project, the coil was pierced and the volume was maintained. The surface was filled with water, and concrete impermeability instruments were installed. After impregnation, the impermeability was observed until the concrete penetrated. Coil test specimen size diameter of about 180mm. BAC coil under normal conditions and post-concrete pouring after the anti-water pouring test C30 concrete poured on the coil, and then vibrated with a vibration table, placed 241 in 230 Under standard curing conditions for 28 days, a concrete impermeability tester was installed, pressurized to 0.4 MPa, and maintained at approximately 24 1 for each pressure of 0.1 MPa for 81 until the concrete penetrated. Since the impermeability of the formulated base concrete is about 0.6 MPa, the test piece seeps at a pressure of 0.6 MPa during the test. At this time, the coils sticking to the concrete immediately start to be observed, and no water entrainment phenomenon is observed on the bonded surface.
After the BAC membrane was covered with dust, it was placed on the bonded surface of the flat membrane after being bonded with the post-concrete. The clay was then kept for 7 days. Then the floating sand was rinsed with water and the C30 concrete was poured on the membrane. Then, using a vibratory table to tap, place 241 at 23 o'clock, cure for 28 days under standard curing conditions, insert a concrete impermeability meter, pressurize to 0.4 MPa, and maintain approximately 241 for each pressurization 0.1 MPa to maintain 81 until the concrete seeps. When the test piece seeped at 0.6MPa, it immediately began to stick to the concrete and there was no drowning phenomenon on the adhesive surface. ) After the BAC coiled with cement powder and post-concrete pouring after the anti-hydrophobic test cement grade 32.5 cement powder was spread on the flat surface of the coil adhesive surface, keep 7d, then rinse the surface of cement Powder, the C30 concrete is poured on the coil, and then vibrated with a vibrating table, placed 24 in 230 under standard curing conditions for 28 days, filled with a concrete impermeability meter, pressurized to 0.4 MPa, and maintained approximately 24 1 per Pressurize 0.1MPa for 8h until the concrete seeps. When the test piece seeped at 0.6MPa, it immediately began to stick to the concrete and there was no drowning phenomenon on the adhesive surface.
The above test shows that even if the surface is punctured, the waterproof membrane pasted on the water surface will only produce water seepage at the piercing point, and will not produce drowning water at the piercing point. The actual construction only needs to be applied at the piercing point. The coil can be repaired; after the project is completed, the leakage is found during use, and only the grouting at the seepage point is plugged, and no large-area plugging treatment is required.
Through this research project, it has been found that BAC coils can be constructed by direct pouring of concrete; for the pre-paved coils in construction, after removing the mucous membranes, dust, cement powder, etc. shall be applied during construction as long as the concrete is poured. Before washing and moistening, it can still guarantee the bonding effect; BAC can resist acid, alkali and salt solution, and it is still well bonded after being soaked in acid, alkali and salt solution; BAC film will not produce blemishes as long as it is bonded with the base layer. The water phenomenon ensures the waterproof and impervious requirements of the project; since the BAC coil is self-adhesive, it is easy to repair.
2 Engineering Application Examples BAC pre-paste anti-sticking technology has been successfully applied in some tunnels and underground projects. Two of them are briefly introduced.
2.1 Nanjing Metro Jiuhuashan Tunnel The Nanjing Metro Jiuhuashan Tunnel has a total length of 445m, an excavation width of 32m, and a section of 297m2. It is the first case of a city with a large section triple arch passing through a broken mountain tunnel. The project uses BAC pre-paste anti-sticking technology to mechanically fix BAC coils to primary linings.
2006.3 China Construction Waterproofing k7 2.2 Beijing Oriental Rose Garden Beijing Oriental Rose Garden is a noble residential area in Chaoyang District, Beijing. Its waterproof area is approximately 200,000 m2. The underground waterproofing project adopts BAC membranes and saves water on the floor. The layer of 50mm thick stone concrete protective layer practice (the picture shows the construction site). During the construction process, the civil construction unit and Zhuobao actively cooperated and adopted the following measures: When carrying out vertical and horizontal transportation of steel bars, the principle of gentle handling shall be observed. Temporary protective measures shall be adopted for the steel bar lifting point to avoid the reinforcement. Broken coils.
During the welding operation, wood or metal sheet is used as a temporary protection baffle on the welding operation surface, and water is sprayed on the corresponding BAC web to prevent the welding dross from burning the coil.
Spread cement powder on the upper surface of the coil to avoid the sticking of the coils when the reinforcing steel is bundled.
In the follow-up construction process of the waterproof layer, the waterproof construction unit will follow up. If the coil is found to be damaged, the BAC coil sheet will be used as a remedial measure for timely repair.
By adopting this approach, not only the material and manpower of the protective layer can be saved, but also the construction period can be shortened. In particular, during the winter construction period, the cost of the insulation measures required for the protection layer construction and conservation can be saved, and the construction unit can bring considerable economic benefits, and at the same time, it ensures The BAC coil waterproof layer and the reinforced concrete structural layer are firmly bonded to avoid the occurrence of drowning, thereby fundamentally ensuring the waterproof effect of the bottom plate.
3 Promotion of anti-sticking technology for prefabrication of BAC coils conforms to the concept of building a conservation-oriented society The production and use of waterproof materials must consider one issue: how to use resources rationally and how to be more conducive to the sustainable development of society. As one of the most common petroleum by-products, bitumen is accompanied by a large number of refining processes, with a wide range of sources and stability. BAC membranes are asphalt-based waterproof materials that meet the basic requirements for the rational use of resources.
The traditional waterproof material uses a large amount of solvent to dilute the primer and the adhesive in the construction process, or needs to use the surface of the fuel barbecue coiled material. According to the calculation of 200 million m2 coil per year, it is conservatively estimated that the consumption of solvents (xylene, gasoline, etc.) may be as high as 20,000 tons or more. This brings with it a series of problems, such as environmental pollution, hidden dangers in firefighting, etc. What is even more striking is that there are accidents caused by poisoning or suffocation of workers due to volatilization of solvents every year. The resulting occupational diseases cannot be ignored. Application of BAC Coil pre-paste anti-adhesion technology, no solvent during construction, no hot-melt barbecue, no volatile matter, no pollution, construction process is not toxic to workers, can be regarded as a waterproof green energy technology.
In practical application of BAC coil pre-paste anti-sticking technology, no special leveling layer is required, and a 50 mm thick concrete protective layer is omitted in the bottom plate or the back arch area. At the same time, since BAC coils are constructed with low requirements for the grassroots level (no special screeding, protective layer construction and maintenance time are required, the basic layer moisture content does not need to be less than 9%, so there is no need to consider waiting for the basement drying period), and the process is simple. Can greatly shorten the construction period of waterproofing. It can be seen that the application of BAC coil pre-pitch anti-sticking technology can save construction costs.
In summary, the application of BAC coil pre-paste anti-sticking technology will achieve incalculable economic and social benefits in terms of rational use of resources, protection of the environment, energy and materials conservation, and construction cost savings, and it is worth promoting.
Deputy Director of Quality Supervision, Inspection and Test Center of Waterproof Materials for Industrial Buildings. contact
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