Assessment of The Effectiveness of Secondary Horizontal Insulation Against Rising Damp Performed by Chemical Injection

3rd World Multidisciplinary Civil Engineering, Architecture, Urban Planning Symposium

土木建筑工程;文学

Monczynski, Bartlomiej^1 ; Ksit, Barbara^1 ; Szymczak-Graczyk, Anna^2

Pozna University of Technology, Piotrowo 5, Pozna

60-965, Poland^1

Pozna University of Life Sciences, Pitkowska 94E, Pozna

60-649, Poland^2

关键词: Building protection;    Capillary transport;    Capillary water absorption;    Continuous layers;    Historical buildings;    Injection schemes;    Injection technology;    Mechanical methods;   

Others  :  https://iopscience.iop.org/article/10.1088/1757-899X/471/5/052063/pdf
DOI  :  10.1088/1757-899X/471/5/052063

学科分类：土木及结构工程学

来源: IOP

【 摘 要 】

Dampness in basement walls caused by capillary rise of water from the ground, as well as possible resulting damage, is very unfavourable phenomenon. This problem mainly concerns historical buildings and other structures erected before 1920, and the destruction is caused by lack, damage or technical wear of insulation. However, it can also arise in relatively new buildings where insulation was made incorrectly (or was not made at all). Creating a barrier that interrupts the capillary rise of moisture in the existing wall, i.e. secondary horizontal hydro-insulation is perceived as one of the most difficult, from a technical point of view, tasks in the field of building protection against water and dampness. The so-called mechanical methods are seen as the safest. Assuming that the works will be flawlessly planned and executed, a durable layer, impermeable to water and thus completely inhibiting the capillary transport of moisture, is formed in the cross-section of the wall - in many cases resulting in highly efficient isolation as "in a new building" 1[1]. However, due to practical limitations, mechanical methods are used much less frequently than injection schemes. By injection, injection technology or chemical injection is meant the introduction of injection fluid into the masonry, with the following three distinguishable ways of applying an injection agent: penetration, pressure and pulse in the form of an aerosol. The technology must ensure equal distribution of an injection agent within the entire wall cross-section, and its principle of operation is to create a continuous layer interrupting capillary rising to obtain (after some time) an area with regular dump in the masonry zone above the membrane. Injection methods, although widely used, are associated with a greater risk of partial or complete failure. The universality of application combined with the risk of failure has encouraged the search for a parameter to assess the effectiveness of secondary horizontal insulation. A suitable parameter is the AQ coefficient (from German - Abdichtungs Qualität) based on the capillary water absorption coefficient, proposed by Venzmer et al3. The article presents research results on the effectiveness of chemical injections performed in reference walls made of ceramic bricks. The membrane was made using three different injection agents: formulation based on silicates (mixture of silicates and alkaline methyl silicates), silicon micro-emulsion and silane-based injection cream. In the injection zone, the drill cores were taken to perform capillary water absorption coefficient measurements. In order to obtain reference samples, additional drills were made above the impregnation zone protected with the injection agent. Both the measurements made and the calculated AQ coefficients proved the effectiveness of the abovementioned injection agents.