A. Alsabry

Specification of the process of chloride extraction from reinforced concrete based on the inverse task of the diffusion equation

Abstract When the structure of reinforcement is in danger of chloride corrosion it is possible to prevent this disadvantageous phenomenon through exposing the cover to the influence of an electric field. The forces of an electric field considerably reduce chloride ions in pore liquid in concrete, which helps to rebuild a passive layer on the surface of the reinforcement and stops corrosion. The process of removing chlorides can be described with multi-component diffusion equations. However, an essential parameter of these equations, the diffusion coefficient, can be determined on the basis of an inverse task. Since the solution was achieved for one-dimension flow, the method applied can be confirmed by experimental results and the material parameters of the process can be determined theoretically. Some examples of numerical calculations of the effective electro-diffusion coefficient of chloride ions confirmed the usefulness of the theoretical solution for generalizing experimental results. Moreover, the calculation process of the numerical example provides some practical clues for future experimental research, which could be carried out in close connection with the theoretical solution.

The Use of Electrodiffusion for Removing Chlorides from Concrete

Abstract The article presents a description of ion migration in a concrete pore liquid caused by an external electric field. The equation of the flow of aggressive chloride ions is formulated on the basis of partial equations of mass balance. It is assumed that electrochemical potential is in classical form, then an attempt is made to determine the average diffusion coefficient using the inverse diffusion Eq.(3.9).

Essential Factors For The Changes In Concrete During Electrochemical Extraction

Abstract The objective of the article is to present one of the most significant factors affecting electrochemical removal of chloride ions from concrete. Based on the literature findings, tests were carried out on specimens containing chloride admixtures introduced to the cement grout, on elements subjected to chloride penetration from the solution in laboratory conditions and on fragments of constructions penetrated by chlorides as a result of a long-term exposure to seawater.

Evaluation of the Influence of Wind-Driven Rain on Moisture in Cellular Concrete Wall Boards

Abstract The non-stationary moisture level of a cellular concrete wall board in a heated utility building located in the northern part of the town of Brest (Belarus), depending on the climatic influence, was assessed in this work. The results were obtained both in a calculation experiment and a physical test. It was observed that the main reason for the high moisture levels in cellular concrete is wind-driven rain intensifying the process of free capillary moisture transfer. A comparative analysis of the results of the physical test and the calculation experiment showed that the THSS software elaborated by the authors was able to predict the actual moisture levels of the shielding structure under study accurately enough when precise data concerning the thermal and physical characteristics of the materials as well as the occurring climatic influences were submitted.

Analysis of Energy Consumption and Possibilities of Thermal-Modernization in Residential Buildings in Poland Case Study: The Town of Zielona Góra

Abstract The article presents an analysis of buildings belonging the Department of Public Utilities and Housing in Zielona Góra. The research was based on a set of questions for building operators. The questionnaires consisted of 30 questions concerning general and detailed information about the buildings. In order to clearly present the results, this article includes data only about residential and residential-commercial buildings. Forty building built in different periods were selected for analysis.