Hygric properties of porous building materials are important for hygrothermal analysis. Their experimental determination is however not always reliable, shown by the discrepant results from different laboratories on the same materials. In this study, a recent round robin campaign initiated by KU Leuven (Belgium) and participated in by eight institutes from different countries is reported. Ceramic brick was selected as the target material. The bulk density and open porosity from vacuum saturation tests, the capillary absorption coefficient and capillary moisture content from capillary absorption tests, and the vapor permeability from cup tests were measured. Results were analyzed statistically and compared with a previous round robin project, EC HAMSTAD. The reproducibility errors for determining the capillary absorption coefficient were noticeably reduced when compared with the EC HAMSTAD project, and the different laboratories in the present study obtained similar results from vacuum saturation tests and capillary absorption tests without a common protocol. For cup tests, large inter-laboratory discrepancies still exist. However, with a stringent common protocol different laboratories achieved consistent results. For all properties a common protocol did not change the average results of all laboratories.

Non-Newtonian fluid is a kind of fluid that its shear stress is not always keeps a linear relationship with the shear strain rate. An overview of its applications was made here. Based on the special rheological properties, non-Newtonian fluids are divided into different types and used as additives, mediums and protective materials in many fields. The paper focuses on its applications in fluid rheological properties improving, damping devices, individual protection equipments and mechanical processing. The main achievements in application of the non-Newtonian fluid were introduced and a further prospect was also summarized.

No abstract

No abstract

No abstract