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Badania doświadczalne wytrzymałości betonu zawierającego zmielony popiół z osadnika

Yuvaraj K., Ramesh S.

Cement Wapno Beton

2021

R. 26, nr 3

253--262

W obecnych czasach zużycie energii elektrycznej gwałtownie wzrasta z każdym rokiem, ze względu na industrializację. Węgiel jest surowcem do produkcji energii elektrycznej w elektrociepłowniach. Szczególnie duża ilość niewykorzystanego popiołu jest wyrzucana do osadników, co stanowi poważny problem dla wielu krajów rozwijających się. Ponadto składowanie popiołu w osadnikach powoduje zagrożenia dla środowiska, takie jak zanieczyszczenie gleby i wody. Zidentyfikowanie realnej alternatywy dla wykorzystania popiołu z osadników staje się potrzebą chwili, aby uniknąć tych zagrożeń dla środowiska. W niniejszej pracy badawczej podjęto próbę częściowego zastąpienia cementu popiołem z osadnika jako dodatku mineralnego w betonie, co w znacznym stopniu ograniczy szkodliwy wpływ popiołu z osadnika na środowisko. Popiół ten zmielono do wielkości 45 μm i użyto go do zastąpienia cementu w betonie w proporcjach 5, 10, 15, 20 i 25% masy. Przeprowadzono badania wytrzymałości na ściskanie, zginanie oraz rozciąganie przy rozłupywaniu uzyskanych betonów. Wyniki badań wykazują, że dodatek 10% popiołu z osadnika znacznie zwiększył wytrzymałość betonu w wieku 7, 28, 56 i 90 dni.

In the present era, the consumption of electricity has increased rapidly with each passing year, due to the industrialization. Coal is a raw material for the production of electricity in the thermal power stations. Particularly, a large amount of unused ash is dumped in ponds, which are major problem concerning many developing countries. Further, dumping of ash in ponds causes environmental hazards effects such as soil, land and water pollution. Identifying a viable alternative to utilize pond ash becomes a necessity, to avoid these environmental hazards. In this research work, an attempt has been made to partially replace cement by the pond ash as a supplementary cementitious material [SCM] in concrete, which will considerably reduce the hazardous effects of pond ash, to the environment. The pond ash was ground to 45 μm and it was used to replace the cement in concrete by proportions of 5, 10, 15, 20 and 25% by mass. Test on compressive strength, split tensile strength and modulus of rupture were conducted on concrete mixes. The result indicate that the addition of 10% pond ash to concrete significantly increased the strength properties of the concrete at the age of 7, 28, 56 and 90 days.

Evaluation the Solidification/Stabilization of Heavy Metals by Portland Cement

Al-Kindi Ghayda Yaseen

Journal of Ecological Engineering

2019

Vol. 20, nr 3

91--100

Numerous solutions are used in the site to treat pollution, including remediation of heavy metals and hazardous wastes by solidification/stabilization (S/S) with cement as a binder. S/S is one of the most commonly methods used for treating inorganic wastes. The objective of this research was using unconfined compressive strength test, and EPA Toxicity Leaching Procedure TCLP method 1313, to test the effectiveness performance, and efficiency of the solidification/stabilization method for treatment of some heavy metals (Fe, Zn, Mn, Cr) contaminated sands using ordinary locally produced Portland Cement type A. In this study, three loads of pollution in three mix designs by contaminated sands were used. As a result of the unconfined compression test, it was observed that the value 1–15 MPa with OPC cement content 25% in the solidification/stabilization process was good enough to comply with the limited value set by the (US EPA). In addition, the concentration of zinc ions was 500 kg/mg, 1500 kg/mg, and 3000 kg/mg, which caused an increase in compressive strength in the early period of age, and a decrease at a later age. An increase in the iron ion concentration caused an increase in the compressive strength at a later age, the effective retention percentages were (97, 93.5, 96 and 92) for iron, zinc, manganese and chromium ions, respectively, which exceeded 3000 mg/kg initially. The high effectiveness in holding and retaining metals within the matrix of solidification/stabilization at the particle size above 9.5 mm was found as well. The samples (Mn and Cr) with the low amount of cement in the mix treatment were not able to retain the required TCLP regulatory limits value, and the initial extraction pH 4.9. However, the final pH 9.5 is alkanet and stabilization effects of the cement matrix.