Papers by Keyword: Loss of Ignition

Abstract: The influence of fly ash quality and quantity on abrasion resistance of hardened concretes with siliceous fly ash addition is analysed in the paper. Abrasion resistance was measured in two standard tests according to EN 1338: 2005: reference test of the Wide Wheel and alternative test of the Bohme. Cement was replaced with 20, 35, and 50% of Class F siliceous fly ash in three categories of losses of ignition A, B and C by mass. The water to binder ratio, the air-entraining and the workability of mixtures were maintained constant at 0.38, 4.5% and 150 mm respectively. Test results indicated that in both methods, all tested concretes according to EN 1338: 2005 could be classified to 4-the highest class of abrasion resistance. In reference test of the Wide Wheel fly ash quality and quantity not influences abrasion resistance. However, in alternative, Böhme test abrasion resistance lowering with growth quantity of fly ash in binder, while loss of ignition of fly ash no influenced abrasion resistance. There were no correlation between the abrasion resistance and the compressive strength.

Abstract: The optical measurement of thermo-mechanical properties allows the sample to be completely free from constraints. This enables the possibility to measure the true change in size or volume of a material during a sintering process. Thanks to the fact that the measure is carried out with no contact in becomes possible to carry out other measurements during the test, like the change in mass. Joining a double beam optical dilatometer and an electronic scale we can measure simultaneously the change in size with a resolution of one part over 100.000 and the change in weight of the specimen, with a resolution of 1 part over 10.000. Moreover, thanks to a innovative temperature controller design, the heat treatment can be designed with complete freedom, even from a mathematical formula (i.e. sinusoidal or exponential) and it can be controlled by the change in size of the specimen during the test. This makes it possible to perform the controlled rate sintering (shrinkage) even if the driving force of the sintering process is the viscous flow of glassy phases, like in traditional ceramics.