• Environmental Engineering Research
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• v.24 no.2
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• pp.246-253
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• 2019

This study was conducted to explore the optimum proportion of zeolite and zeolite-kaolin as additives to cement clinker and gypsum samples, while maintaining the strength properties of produced environmentally sustainable cements. According to the British standard method, zeolite was added to cement clinker in proportions of 5-12% and 10-12% by weight, respectively, in the preparation of samples of zeolite-containing cement and zeolite-kaolin-based cement. Kaolin was used as a second additive as 10-20% of the total weight. The compressive strength tests were performed on base cement samples according to a standard procedure given in ASTM C109 Compressive Strength of Hydraulic Cement. These values were compared with those of the reference sample and the Omani allowable limits. The results indicated that the best compressive strength values were obtained with 88% cement clinker, 5% gypsum, and 7% zeolite for the zeolite-containing cement. Quantities of 70% cement clinker, 5% gypsum, 10% zeolite, and 15% kaolin gave the best results for zeolite-kaolin-based cement, resulting in a substitution of than 25% cement clinker. The study concluded that the partial cement clinker replacement using zeolite/kaolin combination may have a great influence on the reduction of $CO_2$ emission and energy saving in cement manufacturing.

• Applied Chemistry for Engineering
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• v.22 no.4
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• pp.423-428
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• 2011

Hydration characteristics of cement containing zeolite mined at Daepo in Gyeongbuk province were studied for use as a mineral admixture. The cement paste containing zeolite was characterized by the measurement of heat evolution, XRD, EDS, nitrogen adsorption and mercury intrusion porosimetry. The cement paste containing zeolite exhibited tendencies toward acceleration of paste setting and promotion of cement hydration with the increase of zeolite content. The flow of mortar containing zeolite strongly reduced with increase of zeolite content. Compressive strength of the mortar containing zeolite increased very rapidly at an early age in comparison with plain mortar. These results would be related to aluminum species escaped from zeolite particles during the alkali dealumination of zeolite by the hydration process of cement.

• Geomechanics and Engineering
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• v.29 no.4
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• pp.421-434
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• 2022

In the present study, reference samples were prepared using ore preparation facility tailings taken from the copper mine (Kure, Kastamonu), Portland cement (PC) in certain proportions (3 wt%, 5 wt%, 7 wt%, 9wt% and 11 wt%), and water. Then natural zeolite taken from the Bigadic Region was mixed in certain proportions (10 wt%, 20 wt%, 30 wt% and 40 wt%) for each cement ratio, instead of the PC, to prepare zeolite-substituted CPB samples. Thus, the effect of using Zeolite instead of PC on CPB's strength was investigated. The obtained CPB samples were kept in the curing cabinet at a temperature of 25℃ and at least 80% humidity, and they were subjected to the Uniaxial Compressive Strength (UCS) test at the end of the curing periods of 3, 7, 14, 28, 56, and 90 days. Except for the 3 wt% cement ratio, zeolite substitution was observed to increase the compressive strength in all mixtures. Also, the liquefaction risk limit for paste backfill was achieved for all mixtures, and the desired strength limit value (0.7 MPa) was achieved for all mixtures with 28 days of curing time and 7 wt%, 9 wt%, 11 wt% cement ratios and 5% cement - 10% zeolite substituted mixture. Moreover, the limit value (4 MPa) required for use as roof support was obtained only for mixtures with 11% cement - 10% and 20% zeolite content. Generally, zeolite substitution seems to be more effective in early strength (up to 28th day). It has been determined that the long-term strength losses of zeolite-substituted paste backfill mixtures were caused by the reaction of sulfate and hydration products to form secondary gypsum, ettringite, and iron sulfate.

• Journal of The Korean Society of Agricultural Engineers
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• v.55 no.2
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• pp.65-75
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• 2013

In this study, the engineering characteristics of volcanic ash-cement soil mixtures and zeolite-cement soil mixtures are investigated by using unconfined compression test, freezing-thawing test, SEM and XRD analysis. The samples were mixed with volcanic ash from Mt. Baekdusan or porous zeolite, and cement as the ratios of 3.5:1, 4.0:1, 4.5:1, 5.0:1 with and without metakaolin. It is confirmed that compressive strength degraded with increasing of the amount of volcanic ash or zeolite, and increased with addition of metakaolin as a binder. Moreover, test results suggested that the mixtures provided sufficient freezing-thawing resistance. In addition, ettringite as a product of cement hydration was detected by SEM and XRD, and that possibly contributes to the strength of the mixtures.

• Journal of the Korea Concrete Institute
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• v.23 no.2
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• pp.203-209
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• 2011

The cement industry is expected to face a major set-back in the near future due to its large energy consumption and $CO_2$ production, causing global warming. In order to overcome these environmental problems, this research has bee carried out to find a cement substitute material. One possible cement substitute material is Zeolite cement. In this study, the materialistic characteristics of Zeolite cement mortar were evaluated. Natural Zeolite cement mortar was prepared using alkali activation (NaOH) instead of water ($H_2O$) to determine achievable strength and appropriate mixing ratio. Based on the mixing ratio, functional material was added to alkali active agent to harden Zeolite mortar to develop a highly functional construction material. The study result showed that pure Zeolite cement mortar achieved compressive strength of 42 MPa in 7 days depending on the mixing amount of alkaline catalyst and the hardening temperature, showing high efficiency and possibility as a new construction material.

• Computers and Concrete
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• v.17 no.6
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• pp.815-829
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• 2016

This study has been carried out to investigate the effect of the surface properties of Portland cement, diatomite and zeolite on the performance of concrete composites. In this context, to describe the materials used in this study and determine the properties of them, chemical, physical, mineralogical, molecular, thermal, and zeta potential analysis have been applied. In the study, reference (Portland cement), 10%-20% diatomite, 10%-20% zeolite, 5+5%-10+10% diatomite and zeolite were substituted for Portland cement, a total of 7 different cements were obtained. Ultrasonic pulse velocity, capillary water absorption and compressive strength tests were performed on the hardened concrete specimens. Hardened concrete tests have been done on seven different types of concrete, for 28, 56 and 90 days. As a result of experiments it has been identified that both the zeolite and diatomite substitution has a positive effect on the performance of concrete.

• Smart Structures and Systems
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• v.24 no.3
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• pp.415-425
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• 2019

This study was carried out to evaluate the natural zeolite in producing green concrete as an effort to prevent global warming and environmental impact problems of cement industries. To achieve this target, two types of natural zeolites applied to study physical, chemical and compressive strength of concrete containing different percentages of zeolites. The results in comparison with control samples indicate that compressive strength of zeolites mixes increases with the 15% replacement of zeolite instead of cement in all types of samples. In the water-cement ratio of 0.6, results showed an increase in the compressive strength of all percentages of replacement. This results indicate that using natural zeolites could be produced a green concrete by a huge reduction and saving in the consumption of cement.

• Korean Journal of Environmental Agriculture
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• v.26 no.3
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• pp.259-266
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• 2007

Enormous amount of zeolite by-products as a fine powder have been produced while manufacturing commercial zeolite products. Granulation of the zeolite by-products is necessary in order for them to be recycled as soil conditioners or absorbent for various environmental contaminants due to the limitations inherent from their physical properties. We granulated the zeolite powders using Portland cement as a cementing agent and characterized the physical and chemical properties of the granulated zeolite product. The experimental natural zeolite had a Si/Al ratio of 4.8 and CEC of 68.1 $cmol_c\;kg^{-1}$. The X-ray diffractometry (XRD) revealed that clinoptilolite and mordenite were the major minerals of natural zeolite. Smectite, feldspar and quartz also existed as secondary minerals. Optimum conditions of granulated zeolite production occurred when natural zeolite was mixed with Portland cement at a 4:1 ratio and granulated using the extruder, left to harden for one month at $25^{\circ}C$ and treated at $400^{\circ}C$ for 3 hours. The wide spectra of XRD revealed that the granulated zeolite had amorphous oxide minerals. The alkali- or thermal-treated natural zeolite exhibited pH-dependent charge properties. The major minerals of the granulated zeolite were clinoptilolite, mordenite and tobermorite. The buffering capacity and charge density of the granulated zeolite were greater than those of natural zeolite.

• Proceedings of the Korean Institute of Building Construction Conference
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• 2023.05a
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• pp.67-68
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• 2023

After mixing the pozzolan-based powder and water repellent with porosity into the cement mortar, microanalysis and measurement of the water repellent contact angle confirmed that the NZS specimen using natural zeolite had the highest contact angle. The specific surface area is increased due to the porosity of natural zeolite, so the adhesion of silane-siloxane is relatively better than that of FA, and it is judged to have a uniform distribution inside the mortar.

• Computers and Concrete
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• v.22 no.5
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• pp.449-459
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• 2018

Concrete is one of the most widely used construction materials in the world. Producing economical and durable concrete is possible by employing pozzolanic materials. The aim of this study is to underline the possibility of the utilization of natural zeolite in producing concrete and investigate its effects basically on the strength and durability of concrete. In the production of concrete mixes, Portland cement was replaced by the natural zeolite at ratios of 0%, 10%, 15%, and 20% by weight. Concretes were produced with total binder contents of $300kg/m^3$ and $400kg/m^3$, but with a constant water to cement ratio of 0.60. In addition to compressive and flexural strength measurements, freeze-thaw and high temperature resistance measurements, rapid chloride permeability, and capillary water absorption tests were performed on the concrete mixes. Compared to the rest mixes, concrete mixes containing 10% zeolite yielded in with the highest compressive and flexural strengths. The rapid chloride permeability and the capillary measurements were decreased as the natural zeolite replacement was increased. Freeze-thaw resistance also improved significantly as the replacement ratio of zeolite was increased. Under the effect of elevated temperature, natural zeolite incorporated concretes with lower binder content yielded higher compressive strength. However, the compressive strengths of concretes with higher binder content after elevated temperature effect were found to be lower than the reference concrete.