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The development of an ecofriendly binder containing high volume of cement replacement by incorporating two by-product materials for the use in soil stabilization

Jafer Hassnen, Jawad Ibtehaj, Majeed Zaid, Shubbar Ali

Przegląd Naukowy Inżynieria i Kształtowanie Środowiska

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2021

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Vol. 30, No. 1

62--74

EN

The development of an ecofriendly binder containing high volume of cement replacement by incorporating two waste materials for the use in soil stabilization. This paper investigates the possibility of replacing ordinary Portland cement (OPC) by two waste and by-product materials for the use of a silty clay soil stabilization purpose. The soil was treated by 9.0% OPC where this mixture was used as a reference for all tests. Two by-product materials: ground granulated blast furnace slag and cement kiln dust were used as replacement materials. Consistency limits, compaction and unconfined compression strength (UCS) tests were conducted. Scanning electron microscopy (SEM) analysis was carried out for the proposed binder to investigate the reaction of products over curing time. Seven curing periods were adopted for all mixtures; 1, 3, 7, 14, 28, 52, and 90 days. The results showed that the strength development over curing periods after cement replacement up to 45–60% was closed to those of the reference specimens. The microphotographs of SEM analysis showed that the formation of Ettringite and Portladite as well as to calcium silicate hydrate gel was obvious at curing periods longer than 7 days reflected that the replacing materials succeed to produce the main products necessary for binder formation.

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Stabilization/Solidification of Waste Containing Heavy Metals and Hydrocarbons Using OPC and Land Trass Cement

Masrullita, Burhan R. Y. P., Trihadiningrum Y.

Journal of Ecological Engineering

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2018

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Vol. 19, nr 6

88--96

EN

The stabilization/solidification process (S/S) is one of the alternative methods of treating B3 waste, especially heavy metal. The S/S uses cement as the solidification agent. The cement will bind heavy metal pollutants in a monolithic mass with a sturdy structure, thus inhibiting its movement. The presence of hydrocarbons affects the S/S strength. Therefore, it is necessary to add pozzolan material which can absorb hydrocarbon constituting the cement blocking component of pozzolan cement, i.e. Ordinary Portland Cement (OPC) combined with trass soil. This study aims to determine the maximum content of organic materials in the form of hydrocarbons can stabilize/solidify heavy metals contained in wastes containing hydrocarbons. This research is conducted in two steps. Stage I aims to obtain the optimum composition of the mixture. On the other hand, stage II is to determine the maximum content of hydrocarbons in percent weight that can stabilize/solidify organic wastes containing heavy metals – Cu, Cr, and Pb in artificial wastes. The composition of OPC and trass soil was varied at a ratio of 100: 0, 5:25, 50:50, 25:75 and 0: 100. The hydrocarbons used in step II were paraffin, added to the optimum composition of OPC and trass soil with a proportion of 2.5%, 5%, 5% and 10%. The S/S product quality test was performed, involving: compressive strength test, Toxicity Characteristic Leaching Procedure (TCLP) and paint filter test. Strength test was conducted using a compressive strength testing apparatus Toasters Universal Testing Machine Type RAT-200, MFG No. 20380 CAP 200 tf. TCLP test under US-EPA (method 1311). The method of analysis pertaining to heavy metal concentrations involved a colorimetric method for Cr (VI), neocuproine for Cu, and dithizone for Pb. The paint test refers to the US EPA 9095B method. The results showed that the optimum composition of OPC mixture: trass soil was 50:50, which is the composition used in stage II. The results of compressive strength test were 2770 tons/m2. The TCLP test results for heavy metals Cu and Pb with hydrocarbon addition on Cu 10% and Pb 2.5% reached 0.076 and 0.076 mg/L, respectively. The result of the paint filter test indicates that there is no remaining free fluid.

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Badania oporu wnikania chlorków do betonu na cementach portlandzkim zwykłym i niskoalkalicznym

Szweda Z.

Ochrona przed Korozją

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2016

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nr 5

148--153

PL

W artykule przedstawiono badania oporu wnikania chlorków do betonów zwykłych, w składzie których różnicowano jedynie rodzaj zastosowanego cementu. Porównano dwa betony, stosując zalecane w budownictwie komunikacyjnym cementy portlandzkie. W betonie C1 − cement portlandzki CEM I 42,5 R, w betonie C2 – cement portlandzki o niskiej zawartości alkaliów CEM I 42,5 N/SR3/NA. Opór wnikania chlorków określono wyznaczając wartości współczynników dyfuzji wykorzystując termodynamiczny model przepływu chlorków w polu elektrycznym.

EN

This paper shows results from tests on resistance of ordinary concrete, which differed in a type of used cement, to chloride ingress. Two concrete specimens containing Portland cement proposed for use in transport infrastructure engineering, were compared. Concrete C1 with Portland cement CEM I 42,5 R, and concrete C2 – Portland cement with low alkaline content CEM I 42,5 N/SR3/NA. Resistance to chloride ingress was determined by calculating values of diffusion coefficients from the thermodynamic model of chloride flow under the electric field.

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Impedance spectroscopy study of the effect of environmental conditions in the microstructure development of OPC and slag cement mortars

Ortega J. M., Sánchez I., Climent M. A.

Archives of Civil and Mechanical Engineering

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2015

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Vol. 15, no. 2

569--583

EN

In this work, the microstructure of mortars made with an ordinary Portland cement and slag cement has been studied. These mortars were exposed to four different constant temperature and relative humidity environments during a 180-day period. The microstructure has been studied using impedance spectroscopy, and mercury intrusion porosimetry as a contrast technique. The impedance spectroscopy parameters make it possible to analyze the evolution of the solid fraction formation for the studied mortars and their results are confirmed with those obtained using mercury intrusion porosimetry. The development of the pore network of mortars is affected by the environment. However, slag cement mortars are more influenced by temperature while the relative humidity has a greater influence on the OPC mortars. The results show that slag cement mortars hardened under non-optimal environments have a more refined microstructure than OPC mortars for the studied environmental conditions.