Niezwykłe konstrukcje

Evidence: 41 • authority: 88

ZJAWISKO KRADZIEŻY WODY PUBLICZNEJ W STAROŻYTNYM RZYMIE. THE THEFT OF PUBLIC WATER IN ANCIENT ROMESummaryThe theft of the public water delivered to the city by the aqueducts was a common phenomenon in ancient Rome. It was perpetrated both by private persons as well as by the officials and services responsible for the proper functioning of the city’s water supply. The most frequent abusers were the procuratores, aquarii, vilices, and libratores. Various methods were used to prevent water fraud. They included legal means as well special technology for the prevention and faster and more effective detection of instances of water theft and other abuses connected with its distribution.

Evidence: — • authority: 80

Development of Volcanic Ash Concrete: Strength, Durability, and Microstructural Investigations

Evidence: — • authority: 80

Effect of Pozzolanic Reactivity of Volcanic Ash in Hokkaido on the Durability of Volcanic Ash Concrete

Evidence: — • authority: 88

INVESTIGATING THE INFLUENCE OF SEAWATER AND FLY ASH ON THE COMPRESSIVE STRENGTH AND CARBONATION RESISTANCE OF CONCRETE. This study focuses on the combined influence of seawater and fly ash on the compressive strength and carbonation resistance of concrete, addressing critical aspects for sustainable construction, particularly in coastal and marine environments. The increasing demand for sustainable building materials and the need to utilize industrial by-products like fly ash as a partial replacement for cement are driving factors. However, the use of seawater in concrete mixing, especially in conjunction with supplementary cementitious materials, introduces complexities regarding long-term…

Evidence: — • authority: 88

Study on the Effect of Fly Ash on Mechanical Properties and Seawater Freeze–Thaw Resistance of Seawater Sea Sand Concrete. When using seawater and sea sand as mixes, the mechanical properties and durability of concrete are adversely affected because the raw materials themselves contain harmful ions. Fly ash is the tailings formed in the process of industrial production, the use of which does not require the burning of clinker, reducing CO2 emissions. Moreover, it belongs to a new type of cementitious materials with low emissions and high environmental protection. Fly ash enhances the properties of concrete and reduces the effect of harmful ions on concrete. Based on the above considerations…

Evidence: — • authority: 88

Performance of Concrete Containing Water-Hyacinth Ash (WHA) as Cement Replacement: Resistance to Elevated Temperature and Seawater Exposures. The current research aims at determining the resistance of concrete mixtures containing the ashes resulting from the water-hyacinth plants [1] as a cement replacement to elevated temperature and to seawater. Two types of water-hyacinth ashes (WHA); burnt in open air and burnt in a closed oven at 600°C for 30 minutes were used as partial replacement materials of ordinary portland cement in concrete mixtures with percentages of up to 15% (by weight of cement). The concrete mixtures were designed with three coarse aggregates types; gravel, dolomite,…

Evidence: — • authority: 80

PROVENANCING OF LIGHTWEIGHT VOLCANIC STONES USED IN ANCIENT ROMAN CONCRETE VAULTING: EVIDENCE FROM ROME

Evidence: — • authority: 72

Phillipsite is a mineral series of the zeolite group; a hydrated potassium, calcium and aluminium silicate, approximating to (Ca,Na2,K2)3Al6Si10O32·12H2O. The members of the series are phillipsite-K, phillipsite-Na and phillipsite-Ca. The crystals are monoclinic, but only complex cruciform twins are known, these being exactly like twins of harmotome which also forms a series with phillipsite-Ca. Crystals of phillipsite are, however, usually smaller and more transparent and glassy than those of harmotome. Spherical groups with a radially fibrous structure and bristled with crystals on the surface are not uncommon. The Mohs hardness is 4.5, and the specific gravity is 2.2. The species was est…

Evidence: — • authority: 72

Lime is an inorganic material composed primarily of calcium oxides and hydroxides. It is also the name for calcium oxide which is used as an industrial mineral and is made by heating calcium carbonate in a kiln. Calcium oxide can occur as a product of coal-seam fires and in altered limestone xenoliths in volcanic ejecta. The International Mineralogical Association recognizes lime as a mineral with the chemical formula of CaO. The word lime originates with its earliest use as building mortar and has the sense of sticking or adhering. These materials are still used in large quantities in the manufacture of steel and as building and engineering materials (including limestone products, cement,…

Evidence: — • authority: 72

Roman concrete, also called opus caementicium, was used in construction in ancient Rome. Like its modern equivalent, Roman concrete was based on a hydraulic-setting cement added to an aggregate. Many buildings and structures still standing today, such as bridges, reservoirs and aqueducts, were built with this material, which attests to both its versatility and its durability. It was previously thought that its strength was enhanced by the incorporation of pozzolanic ash where available (particularly in the Bay of Naples). The addition of ash prevented cracks from spreading. However, research in 2023 has shown that the incorporation of mixtures of different types of lime, forming conglomerat…