Concrete hollowing treatment scheme, materials and process
The causes of concrete floor hollowing are:
(1) The surface of cushion (or base course) is not cleaned, with floating ash or other Dirt, which seriously affects the combination with the surface course;
(2) During construction, the surface of the cushion (or base course) is too dry. After the surface course is laid, the moisture is lost, which makes the strength not high and the bonding between the surface course and the cushion course not firm. If the dry cushion (or base course) is not washed, the dust on the surface is difficult to remove mortar It also plays a certain isolation role;
(3) There is ponding on the surface of the cushion (or base course). After the surface course is paved, the water cement ratio of the ponding part will affect the bonding between the surface course and the cushion course, which is easy to make the surface course hollow;
(4) In order to increase the bonding force between the surface course and the cushion, brush cement If the mortar binding course is brushed too early, the cement brushed has dried and hardened when the surface course is laid, which not only has no binding force, but plays an isolation role instead. If the method of slurry sweeping is adopted, the dry cement surface is not easy to spread evenly, and there is more or less watering, which is easy to cause dry ash layer and ponding pit, and the surface layer will be empty in the future.
（5） door The brick layer at the mouth is too high or the brick layer is not wet enough, making the surface mortar too thin and drying too fast, resulting in local surface cracks and hollowing.
For the plant with hollowing ground, it is recommended to use Nanjiang series products for grouting repair. Fill the empty position of the cement floor to ensure the integrity and durability of the building and meet the requirements of normal use.
The original repair method is chiseling and re drilling concrete, which not only takes time and labor, but also will cause vibration damage to the concrete during cutting and chiseling, which will expand the hollowing area; The more common problem is that there is still the possibility of hollowing after re beating the concrete.
Comparison table of hollowing repair methods
S/N | Repair method | Main steps | Applicable sites | characteristic |
one | Re concrete after cutting | Cut off all empty drum positions, clean the ground, perform interface treatment, and re concrete. | The project that has not been delivered for use does not require high construction period and has sufficient time. | The site shutdown will have a great impact on the owner, and the construction period will be long. The vibration damage expands the area of the empty drum. When re concreting, there is a hidden danger of secondary hollowing. |
two | High pressure grouting repair | Holes shall be drilled in the hollow parts, grouting nozzles shall be buried, special resin shall be poured, the filling condition shall be checked, and the repair shall be completed. | It has a wide scope of application and no special requirements for the site. | The construction is simple and fast, and the construction period is short. The repair process will not affect the normal use of the Owner. |
Zhuzhijie AB-5 grouting resin is a special adhesive for hollow treatment of cement floor. Grouting treatment can be carried out for various conditions such as hollow treatment of mortar, concrete and brick board.
AB-5 hollow grouting resin, specially developed for repairing hollow cement floor, is widely used in concrete Stone The problem of empty drum can be completely solved after repairing by filling with low pressure and high pressure.
The repair method of concrete hollowing has become a common quality problem in construction projects. Concrete cracks are often caused by the untimely repair of concrete hollowing on the ground, which may cause complete damage of concrete in serious cases. Therefore, the treatment of concrete hollowing is a problem we need to solve today.
- hollowing
The hollowing is caused by the air in the original masonry and plaster layer. When testing, the hollowing is caused by knocking the plaster layer and leveling layer gently with a hollowing hammer or a hard object. When viewed with the naked eye, the empty drum part is generally slightly higher than the overall plane around, and is often accompanied by cracks. You can find that it is empty by pressing down with your fingers. Tap gently with a small hammer one by one, and you can hear the empty sound different from the sound of other parts. Here is the empty drum.
Chinese name: Topcoat English name: topcoat Definition: coating in the middle layer and bottom layer of the coating system. Applied discipline: mechanical engineering (first-class discipline); Surface engineering (secondary discipline); Coating (tertiary discipline)
Pinyin: h ù nn í ngt, Or after hardening, composite materials with agglomerative structure can be formed (usually cementitious materials, water, fine aggregates, coarse aggregates, admixtures and mineral admixtures are added when necessary, and mixed in appropriate proportions. Concrete is one of the major civil engineering materials in the contemporary era. Concrete is characterized by rich raw materials, low prices, and simple production processes, so its consumption is increasing. At the same time, concrete also has the characteristics of high compressive strength, good durability, and wide range of strength grades. These characteristics make it widely used. It is not only used in various civil engineering, such as shipbuilding, machinery industry, marine development, geothermal engineering, etc., but also an important material. Concrete is a kind of building material full of vitality. With the continuous development of concrete composition materials, people's understanding of material composite technology is constantly improving. The performance requirements for concrete are not limited to compressive strength, but on the basis of strength, more attention is paid to the balance and coordination of comprehensive indicators such as durability and deformation performance of concrete. The requirements for various performance indicators of concrete are more clear, detailed and specific than before. At the same time, the improvement of the level of construction equipment and the continuous emergence and promotion of new construction processes have made the concrete technology adapt to different design, construction and use requirements and develop rapidly. Concrete is not an isolated single material. It is inseparable from the development of raw materials for concrete and the development and change of engineering application objects of concrete. Concrete should be taken seriously from the perspective of civil engineering. The same is true for concrete mix design. First, analyze the structure, component characteristics and design requirements of the project, estimate possible adverse conditions and risks, base on local raw materials, and then adopt scientific, reasonable and feasible technical routes and means. Prepare high-quality concrete that meets the design requirements, construction process requirements and use requirements.
