Browsing by Subject "compressive strength"

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Czynniki wpływające na prędkość wiercenia
(Data obrony: 2021-02-02) Musiała, Dawid
Wydział Wiertnictwa, Nafty i Gazu
Access status: Open Access ,
Factors affected the performance of fire clay refractory bricks
(Wydawnictwa AGH, 2009) Elngar, Marwa A. G.; Mohamed, Fatma M.; El-Bohy, Salwa A. H.; Sharaby, Carmen M.; Shalabi, Mohamed el-Menshawi H.
In this investigation some factors affected the performance of the fire clay refractory bricks such as size of grog, percentage of water added to the raw material, percentage of grog and temperature of firing were studied. The results showed that if the percentage of grog increased the shrinkage of bricks decreased, as well as density of bricks was increasing the porosity and water absorption also increased. Furthermore, with increasing of the added water to the raw material the porosity of the bricks increased and if water absorption increased, density decreased. The characteristics of raw material by such methods as x-ray and chemical analysis were also examined.
Access status: Open Access ,
Mechanical properties of biodegradable bone cement composites
(Wydawnictwa AGH, 2009) Iskander, Berlanty A.; Kamel, Nagwa A.
A material that can be used as a scaffold in tissue engineering must satisfy a number of requirements. These include biocompatibility, biodegradation to non toxic products within the time frame required for the application, process ability to complicated shapes with appropriate porosity, ability to support cell growth and proliferation, and appropriate mechanical properties, as well as maintaining mechanical strength during most part of the tissue regeneration. In the present work, the bone cement composites were prepared by mixing different ratios of calcium sulfate dehydrate ($CaSO_{4}.2H_{2}O$) filler (60, 65 and 70 wt%) with the polyester resin/NV, MMA, NV/MMA monomers mixture. The biodegradability of PSF crosslinked with NV, MMA and NV/MMA loaded with 60% gypsum was studied using Simulated Body Fluid SBF (pH 7.3) in vitro medium. The degradation rate of fumarate based polyesters as well as bone cement composites were measured as the percentage of weight loss over time of exposure to the SBF solutions. The mechanical properties showed different behavior according to the bone cement concentration. The compressive strength and the microstructure were also studied before and after immersing in SBF solution.
Access status: Open Access ,
Microstructural, mechanical and pozzolanic characteristics of metakaolin-based geopolymer
(Wydawnictwa AGH, 2020) Abiodun, Yetunde Oyebolaji; Sadiq, Obanishola Muftau; Odeosun, Samson Oluropo
The use of cement contributes to global $CO_2$ emission and this leads to the depletion of ozone layer, causing global warming. The quest to reduce or eliminate this problem has resulted in the discovery of metakaolin-based geopolymer as an alternative to the use of cement in construction work. In this study, metakaolin obtained as a result of kaolin calcination from some deposits in Nigeria, Ogun (Imeko), Edo (Okpela), Ondo (Ifon) and Ekiti (Isan-Ekiti) were characterized and used to determine the compressive and flexural strength of metakaolin-based geopolymer concrete (Mk-GPC). Cubes of 150 x 150 x 150 mm were used for the compressive strength test and reinforced concrete beams of size 150 x 250 x 2160 mm were produced to test for flexural strength. A water-absorption test was also carried out on Mk-GPC and the effect of ball-milling was assessed on the strength properties. The results from the various tests showed that 800°C for 1 hour of calcination of kaolin gives best combination of performance properties due to the presence of amorphous silica in metakaolin. Mk-GPC gave higher compressive strength and at an early age than ordinary Portland cement (OPC) concrete. The water absorption capacities of Mk-GPC were higher than the control samples. In the flexural strength test, the reinforced beams failed in flexural-shear mode and the shear capacities at 28-, 56- and 90-day curing age of the beams were between 0.656 and 0.938 MPa for Mk-GPC beams and between 0.563 and 0.844 MPa for the control beams. The moment capacities for the beams were between 19.25 and 33.25 (x10$^{3}$ kgm$^{2}$/s$^{2}$) for Mk-GPC beams and were between 22.75 and 28.0 (x10$^{3}$ kgm$^{2}$/s$^{2}$) for the control beams. The study has revealed that metakaolin-based geopolymer can serve as an alternative to cement for sustainable construction in the Nigerian construction industry.
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Petrograficzne uwarunkowania zmienności fizyczno-mechanicznych właściwości wapieni jurajskich ze złoża Ptasznik I koło Jędrzejowa
(Data obrony: 2014-11-28) Figiela, Lilianna
Wydział Geologii, Geofizyki i Ochrony Środowiska
Jurassic limestone mine „Suchowola” on the deposit „Ptasznik I” is within the margin of the Holy Cross Mountains. The deposit has a very low volatility lithology. In order to determine conditions on the petrographic variability of physico-mechanical properties of rock samples, which are used in the study of microscopic and physicomechanical properties. Limestones that make up the deposit are organodetrital built mostly of fine crystalline calcite, although there are also limestone sparite. The average bulk density of the bed is 2.53 g / cm 3, the average absorption of 0.84% and the average compressive strength of 69.86 MPa. On the basis of the data was collected three groups limestone. It has been observed that the limestone containing sparite have better physical and mechanical parameters than limestone containing micrite and a large number of organic components. The deposit meets the criteria for defining a deposit of limestone intended for the needs of the lime industry.
Access status: Open Access ,
Utilization of slags from foundry process
(AGH University of Science and Technology Press, 2017) Pribulová, Alena; Futáš, Peter; Bartošová, Marianna; Petrík, Jozef
The melting of steel or cast iron is one step of the foundry process. The foundry industry uses different types of furnaces, and metallurgical slags are products of the pyrometallurgical processes defecting in these furnaces. Furnace slag is a non-metallic by-product that consists primarily of silicates, alumina silicates, and calcium-alumina-silicates. As a by-product of the melting process, furnace slags vary considerably in form depending on the melted metal furnace types, and slag cooling method used. Most quantity of slags from the foundry processes are created in a cupola furnace that is used for cast iron production. An electric arc furnace is usually used for steel production, but it can be used for cast iron production as well. Universal use features an electric induction furnace. Slags from the melting processes in a foundry can be in the form of gravel, or the slag from a cupola furnace can be granulated. The utilization of slags from foundry processes is very delimited in Slovakia because of their quantity. This article deals with the possibility of using foundry slag as a binder in civil engineering. A basic property of a binder in civil engineering is its hydraulicity, which can be given by compression strength. Four metallurgical slags were tested. The values of the compressive strength of the slags were low, but addition cement to the slags resulted in a strong increase in the value of the compressive strength.
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Wpływ parametrów syntezy na wytrzymałość geopolimerów z popiołów lotnych
(Data obrony: 2017-01-27) Nazarko, Marzena
Wydział Energetyki i Paliw