Method of determining the content of polymer microfibres in cement composites based on utilisation of the buoyancy phenomenon
(22) 17.03.2020
(43) 28.04.2021
(57) The present application relates to a method of determining the content of polymer microfibres in cement composites based on the utilisation of the buoyancy phenomenon. The method is characterized in that a cement composite sample containing microfibres is crushed to grains less than 1 mm in size, the crushed mixture is flooded with a liquid with a density greater than that of the microfibres, but less than the density of the cement matrix, and after mixing and sedimentation the microfibres are collected from the surface, whereupon a portion of an inorganic acid is added to the solution to set free any microfibres bound to the cement matrix, and after mixing additional microfibres are collected from the surface, wherein the addition of acid and collection of microfibres operations are repeated until no microfibres come up to the surface, and then the microfibres thus separated are dried and weighed, and in case they are contaminated, they are additionally ignited at the polypropylene decomposition temperature, as a result of which the microfibres will decompose and only impurities remain whose weight after weighing is subtracted from the dried microfibres, and the final result obtained will indicate the content of microfibres in the tested sample.
(71) Instytut Techniki Budowlane, 00-611 Warszawa (PL)
(84) Designated Contracting States: AL AT BE BG CH CY CZ DE DK EE ES Fl FR GB GR HR HU IE IS IT LI LT LU LV MC MK MT NL NO PL PT RO RS SE SI SK SM TR; Designated Extension States: BA ME; Designated Validation States: KH MA MD TN
