Wpływ wybranych zagrożeń środowiskowych na właściwości hydrofobowe drobnodyspersyjnego wapienia / The Influence of Chosen Environmental Hazards on Hydrophobic Properties of Fine Dispersional Limestone

The paper concerns the results of researches carried out on the changes of hydrophobic properties of fine dispersional limestone caused by chosen corrode substances. The researches were conducted on two grain fractions of fine dispersional limestone, which grain diameter in accordance with the manufacturer’s data (Limestone Mine Czatkowice) equals less than 80 μm for lime meal and 100-400 μm for lime sand accordingly and also on a meal hydrophobized in the limestone and margiel quarry of cement plant in Małogoszcz. Raw materials and hydrophobized ones with the use of stearic acid, silicone preparation and bituminous preparation were tested. The acetic acid, ammonia hydroxide, sodium sulphate were used as aggressive substances. The researches proved the influence of these substances on an absorbability and a compressibility changes of studied materials. The absorbability was measured as changes of the material humidity during the storage in wet conditions. The compressibility was calculated on the base of the results of densimetric measurements such as loose and packed bulk density obtained with the use of measuring cylinder. A small changes in the compressibility coefficient values obtained for corroded materials in the comparison with values obtained for initial materials show that the cohesive properties of both kinds of material are similar. The majority of modified (hydrophobized) materials obtained after corrode process worse waterproof properties than initial materials, but they were still characterised by higher hydrophobization degree than corroded raw materials. No repeatable results were obtained in the case of meal. It was probably caused by a higher reactivity of this material, connected with its little grain diameter. The measurements performed had the preliminary character.