View More View Less
  • 1 Czech Technical University Faculty of Civil Engineering, Department of Structural Mechanics Thákurova 7 166 29 Prague 6 Czech Republic 166 29 Prague 6 Czech Republic
  • 2 Czech Technical University Faculty of Civil Engineering, Department of Physics Thákurova 7 166 29 Prague 6 Czech Republic 166 29 Prague 6 Czech Republic
  • 3 Brno University of Technology Žižkova 17 Institute of Chemistry, Faculty of Civil Engineering 662 37 Brno Czech Republic 662 37 Brno Czech Republic
  • 4 the Academy of Sciences of the Czech Republic Cukrovarnická 10 Institute of Physics 162 53 Prague 6 Czech Republic 162 53 Prague 6 Czech Republic
Restricted access

Abstract  

Methods of thermal analysis are employed in a study of the high-temperature properties of three different types of glass fiber reinforced cement composites together with the measurements of their thermal and hygric parameters. First, basic TG and DTG measurements are carried out to get the first insight into the high-temperature behavior of the analyzed materials. Then, mercury porosimetry and scanning electron microscopy of specimens subjected to the temperatures of 600 and 800C are performed and compared to the reference specimens not exposed to any thermal load. Finally, measurements of thermal and hygric parameters of the studied materials are done and matched with the results of the material characterization experiments. Three main effects are found to influence the thermal and hygric properties of the analyzed materials. The first is the decomposition of the cement matrix, which is clearly a negative factor. The second is the positive effect of the presence of fibers that could partially keep the cement matrix together even after significant decomposition of cement hydration products. The third important factor affecting the thermal and hygric properties is the composition of the particular materials. The application of vermiculite aggregates instead of sand is found to be clearly positive because of its porous character leading to the bulk density decrease without worsening the other properties. Also, wollastonite aggregates are a better choice than sand because of its fibrous character that could partially magnify the effect of fiber reinforcement.