Attention should be paid to the construction of Urethane Grout
For large-volume Urethane Grout, it is particularly noteworthy to maintain the uniformity of Urethane Grout. Urethane Grout pouring block of various parts of the material will inevitably lead to uneven performance, and the performance of the uneven is caused by internal stress, causing cracks.
If the prepared polyurethane grout is easily segregated, or because the construction process can not grasp the appropriate vibrator, making the Urethane Grout bleeding or vomiting, then pour the upper part of the block or more cement, while the lower part of the aggregate more The The dry shrinkage deformation and thermal expansion properties of Urethane Grout are related to the moisture content and volume content of Urethane Grout. The more the cement slurry in the Urethane Grout, the greater the shrinkage deformation, the greater the coefficient of thermal expansion of the Urethane Grout. That is, if the polyurethane grout is segregated, the upper shrinkage deformation and thermal expansion coefficient of the column are increased, and the lower two properties are reduced. From the environmental conditions, it is also usually the upper part of the Urethane Grout first dry and cool, while the lower part of the Urethane Grout in a long period of time to maintain a high humidity and temperature. Therefore, the segregation of Urethane Grout will result in an additional dry shrinkage deformation and poor temperature deformation of the upper and lower polyurethane grouts, as well as an additional tensile stress in the surface Urethane Grout.
From these points of view, the interest on the large volume of Urethane Grout is extremely unfavorable, especially in favor of large volume of Urethane Grout crack. Therefore, in the preparation and construction of large volume of Urethane Grout should pay special attention to this point, and the stability of fresh Urethane Grout as an important indicator to consider, to ensure that the pouring of Urethane Grout has a better uniformity.
Another issue that requires special attention in the construction of large volumes of Urethane Grout is the need to emphasize the design, Urethane Grout preparation and construction of various aspects of cooperation. Large volume of Urethane Grout is different from ordinary Urethane Grout, has a special requirement, and therefore must take some special technical measures, especially some technical measures of temperature control crack, from the previous analysis can clearly see that these technical measures Most of the system with some of the needs of the various links between the cooperation. If not effectively cooperate, some measures can not be implemented. Or even if implemented, can not achieve good results. Therefore, in the construction of large volume of Urethane Grout in particular need to emphasize coordination. Only through the design, Urethane Grout preparation and construction in many ways closely in order to achieve the optimization of the overall construction technology in order to truly solve the large volume of Urethane Grout construction problems.
Summary In recent years, China's large-scale Urethane Grout construction experience can be found, both from the design, or from the preparation and construction of Urethane Grout, China's current level is not low, high-strength Urethane Grout application technology, a variety of Urethane Grout Preparation technology, pumping Urethane Grout and self-dense Urethane Grout construction technology, it should be said to have a certain level, or even a higher level. However, the cracking of large-scale Urethane Grout in China's construction projects is still very serious. The reason is that there is no reasonable combination of these technologies, from the entire large-volume Urethane Grout construction system to optimize, in order to achieve the overall optimization. This is also a commodity Urethane Grout caused by a special division of labor caused by a problem.