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The paper presents results of investigations of influence of major head losses on exploitation properties of water supply pipes after 30-year exploitation. The tested materials were cast-iron pipes with the internal diameter of 150 mm. A flowability drop coefficient ηt with average value of 0.45 was determined. Using the measured values of pressure difference Δp determined the absolute roughness of internal walls of the pipes after 30-year exploitation, which was referred to the new pipelines. The absolute roughness for the exploited pipes was equal to k = 27.6 mm, whereas for the new ones it was significantly lower and equal to k = 0.9 mm. Additionally, an analysis of the chemical and mineral composition of sediments gathered in the investigated pipelines was also performed. The top layer of the sediments was dominated by the compounds of a character of the iron hydroxide: goethite (α-FeOOH) and lepidocrocite (γ-FeOOH), whereas the internal layer was supplemented by the gypsum and sulfur, which was proven by the investigations performed with the use of scanning electron microscope (SEM). The sediment gathered within the pipes is the main reason of ca. 30-fold increase of the absolute roughness, which resulted in the flowability drop of the exploited water supply pipes.
Piotr Wichowski; Marek Kalenik; Agnieszka Lal; Dariusz Morawski; Marek Chalecki. Hydraulic and Technological Investigations of a Phenomenon Responsible for Increase of Major Head Losses in Exploited Cast-Iron Water Supply Pipes. Water 2021, 13, 1604 .
AMA StylePiotr Wichowski, Marek Kalenik, Agnieszka Lal, Dariusz Morawski, Marek Chalecki. Hydraulic and Technological Investigations of a Phenomenon Responsible for Increase of Major Head Losses in Exploited Cast-Iron Water Supply Pipes. Water. 2021; 13 (11):1604.
Chicago/Turabian StylePiotr Wichowski; Marek Kalenik; Agnieszka Lal; Dariusz Morawski; Marek Chalecki. 2021. "Hydraulic and Technological Investigations of a Phenomenon Responsible for Increase of Major Head Losses in Exploited Cast-Iron Water Supply Pipes." Water 13, no. 11: 1604.
Striving for reduction of production costs and constraints on natural resources cause the use of waste materials as substitutes of traditional raw materials to become increasingly important. Dynamic development of sewerage systems and sewage treatment plants observed over the recent years leads to increase of mass of the produced sewage sludge. According to the Waste Law, the municipal sewage sludge can be used if it is properly stabilized, e.g., through thermal processing. This process results in significant quantities of fly ash which must be properly utilized. The paper presents results of investigations of influence of partial replacement of cement by the fly ash from sewage sludge on concrete parameters. It was designed as a C20/25 class concrete mix, based on the Portland cement CEM I 42.5R with various ash content. Physical and chemical properties of the ash as well as frost resistance and the compressive strength of the concrete after 28, 56 and 365 days of curing were investigated. The obtained results of investigations confirm the possibility of application of fly ash wastes as a cement substitute in the concrete manufacturing. If a predefined quantity of cement is replaced by the fly ash, then one can obtain cement composite with good strength parameters.
Gabriela Rutkowska; Marek Chalecki; Mariusz Żółtowski. Fly Ash from Thermal Conversion of Sludge as a Cement Substitute in Concrete Manufacturing. Sustainability 2021, 13, 4182 .
AMA StyleGabriela Rutkowska, Marek Chalecki, Mariusz Żółtowski. Fly Ash from Thermal Conversion of Sludge as a Cement Substitute in Concrete Manufacturing. Sustainability. 2021; 13 (8):4182.
Chicago/Turabian StyleGabriela Rutkowska; Marek Chalecki; Mariusz Żółtowski. 2021. "Fly Ash from Thermal Conversion of Sludge as a Cement Substitute in Concrete Manufacturing." Sustainability 13, no. 8: 4182.