Llw Solidification Incement -Effect of Dilution

1994 ◽  
Vol 370 ◽  
Author(s):  
A. Katz ◽  
A.R. Brough ◽  
T. Bakharev ◽  
R.J. Kirkpatrick ◽  
L.J. Struble ◽  
...  
Keyword(s):  
Compressive Strength ◽  
Heat Evolution ◽  
Early Age ◽  
Porous System ◽  
High Dilution ◽  
Solid Ratio ◽  
Additional Water ◽  
Lower Heat ◽  
High Concentrations

AbstractA simulated Low Level nuclear Waste (LLW) solution was tested for long term solidification in a cement-based matrix. The waste is characterized by high pH and high concentrations of sodium, aluminum, nitrate, nitrite, phosphate and carbonate. The effect of diluting the waste with additional water was studied. The cementitious matrix was composed of cement, fly-ash and clay (21°, 68° and 11° respectively) with high solution to solid ratio (1 liter / 1 kg.). Mixes were prepared at 45°C and cured at 90°C for 28 days.Maximum 28 day compressive strengths and early age heat evolution were achieved by diluting the LLW solution to approximately 67& of its original concentration. More dilution led to a lower heat evolution and compressive strength. No dilution was found to give lower compressive strength, and a heat evolution that was delayed, and lower in intensity. XRD spectra showed formation of zeolites and tobermorite at the higher concentrations (67, 85, and 100& of the concentration of the undiluted simulated LLW), with a change from Na-P1 zeolite for 67& of the undiluted concentration to a sodalite at 100&. SEM observations showed a porous system for the low and high dilution rates but a less porous one for an intermediate level of dilution.

scholarly journals CONTINUOUS MICROSTRUCTURAL CORRELATION OF SLAG/SUPERPLASTICIZER CEMENT PASTES BY HEAT AND IMPEDANCE METHODS VIA FRACTAL ANALYSIS

Fractals ◽  
2017 ◽  
Vol 25 (04) ◽  
pp. 1740003 ◽  
Author(s):  
S. W. TANG ◽  
R. J. CAI ◽  
Z. HE ◽  
X. H. CAI ◽  
H. Y. SHAO ◽  
...  
Keyword(s):  
Compressive Strength ◽  
Fractal Analysis ◽  
Setting Time ◽  
Blended Cement ◽  
Impedance Measurement ◽  
Heat Evolution ◽  
Early Age ◽  
Contact Impedance ◽  
Cement Pastes ◽  
Early Age Hydration

This paper presents a preliminary work to evaluate the influence of slag and superplasticizer on the early-age hydration of cement pastes by an innovative non-contact impedance measurement, heat evolution method, compressive strength and setting time tests. Besides, the cumulative pore volume obtained from modulus and phase of impedance in different hydration sections is taken to continuously correlate the cumulative heat releasing of cement pastes via the fractal analysis. Retarded phenomena and mechanism of hydration in cement pastes incorporated with slag and superplasticizer are studied, respectively. It is found that the compressive strength and setting time have a good linear relation with the slag amount in blended cement pastes.

scholarly journals Effect of Incorporating Nanoporous Metal Phosphate Materials on the Compressive Strength of Portland Cement

2008 ◽  
Vol 2008 ◽  
pp. 1-4
Author(s):  
Dawn M. Wellman ◽  
Kent E. Parker ◽  
Shas V. Mattigod ◽  
Glen E. Fryxell
Keyword(s):  
Compressive Strength ◽  
Low Cost ◽  
Physical And Mechanical Properties ◽  
Metal Phosphate ◽  
Waste Streams ◽  
Nanoporous Metal ◽  
Additional Water ◽  
Cadmium And Lead ◽  
Cement Formulation

Nanoporous metal phosphate (NP-MPO) materials are being developed for removal of contaminant oxyanions (As(OH), , and ), and cations (mercury, cadmium, and lead) from water and waste streams. Following sequestration, incorporation of metal laden NP-MPOs as a portion of cement formulation would provide an efficient and low-cost way to immobilize metal laden NP-MPOs in an easily handled waste form suitable for permanent disposal. There are no known investigations regarding the incorporation of NP-MPOs in concrete and the effects imparted on the physical and mechanical properties of concrete. Results of this investigation demonstrated that incorporating of NP-MPO materials requires additional water in the concrete formulation which decreases the compressive strength. Thus, incorporation of NP-MPOs in concrete may not serve as an efficient means for long-term disposal.

scholarly journals Utilizing Iron Ore Tailing as Cementitious Material for Eco-Friendly Design of Ultra-High Performance Concrete (UHPC)

Materials ◽  
2021 ◽  
Vol 14 (8) ◽  
pp. 1829
Author(s):  
Gang Ling ◽  
Zhonghe Shui ◽  
Xu Gao ◽  
Tao Sun ◽  
Rui Yu ◽  
...  
Keyword(s):  
Compressive Strength ◽  
High Performance ◽  
Carbon Emission ◽  
Iron Ore ◽  
High Performance Concrete ◽  
Cementitious Material ◽  
Early Age ◽  
Ultra High Performance Concrete ◽  
Iron Ore Tailing

In this research, iron ore tailing (IOT) is utilized as the cementitious material to develop an eco-friendly ultra-high performance concrete (UHPC). The UHPC mix is obtained according to the modified Andreasen and Andersen (MAA) packing model, and the applied dosage of IOT is 10%, 20%, and 30% (by weight), respectively. The calculated packing density of different mixtures is consistent with each other. Afterwards, the fresh and hardened performance of UHPC mixtures with IOT are evaluated. The results demonstrate that the workability of designed UHPC mixtures is increased with the incorporation of IOT. The heat flow at an early age of designed UHPC with IOT is attenuated, the compressive strength and auto shrinkage at an early age are consequently reduced. The addition of IOT promotes the development of long-term compressive strength and optimization of the pore structure, thus the durability of designed UHPC is still guaranteed. In addition, the ecological estimate results show that the utilization of IOT for the UHPC design can reduce the carbon emission significantly.

Preparation and Mechanical Properties of Potassium Metakaolin Based Geopolymer Paste

2019 ◽  
Vol 31 ◽  
pp. 38-45
Author(s):  
Hiep Le Chi ◽  
Petr Louda ◽  
Totka Bakalova ◽  
Vladimír Kovačič
Keyword(s):  
Compressive Strength ◽  
Mechanical Strength ◽  
Potassium Hydroxide ◽  
Silicate Solution ◽  
Curing Temperature ◽  
Polymerization Process ◽  
Strength Development ◽  
Early Age ◽  
Molar Ratios ◽  
Additional Water

In this study, geopolymer samples were prepared by mixing metakaolin (MA) with activator solution made of potassium alkali silicate solution, potassium hydroxide flakes, and additional water. The aim of the experiment is to evaluate the mechanical strength of hardened samples based on four test variables including the SiO2/K2O molar ratios, K2O concentration, H2O/MA water coefficient, and curing temperature. The results reveal that K2O concentration and H2O/MA water coefficient impact strongly on the compressive strength, whereas varying of SiO2/K2O molar ratios in the range from 1.0 – 1.4 does not significantly change the compressive strength of geopolymer samples. On the other hand, high-temperature curing leads to higher mechanical strength of the samples in the early-age compared to curing at room temperature, due to the faster establishment of hard structure in the early-age of geo-polymerization process. However, curing at a temperature range of 80°C – 100°C contributes the non-linear strength development of the samples over the time.

scholarly journals HYDRATION OF PLASMA-TREATED ALUMOSILICATE BINDERS

2014 ◽  
Vol 54 (5) ◽  
pp. 348-351
Author(s):  
Vít Šmilauer ◽  
Oleg Babchenko ◽  
Štepán Potocký ◽  
Alexander Kromka
Keyword(s):  
Compressive Strength ◽  
Fly Ash ◽  
Plasma Treatment ◽  
Material Science ◽  
Hydration Heat ◽  
Early Age ◽  
Hydrophilic Surface ◽  
Hydration Kinetics ◽  
Early Age Hydration

Plasma treatment offers several applications in material science. In this research, the potential of plasma treatment is explored on the hydration of hydrophilic CNT-enriched cement and hydrophilic fly ash. The evolution of the hydration heat and the compressive strength show that a hydrophilic surface slightly accelerates the early-age hydration kinetics, while the long-term properties remain unchanged.

scholarly journals A Review on Early Age and Long-term Compressive Strength of High-volume Fly Ash Concrete

2018 ◽  
Vol 207 ◽  
pp. 01004
Author(s):  
Mu Li
Keyword(s):  
Compressive Strength ◽  
Fly Ash ◽  
High Volume ◽  
Partial Replacement ◽  
Early Age ◽  
Fly Ash Concrete ◽  
Power Stations ◽  
High Volume Fly Ash ◽  
Curing Age

Fly ash is a by-product of the combustion of the coal-fired electric power stations, and disposal of fly ash has been one of the environmental challenges. Much of the studies have been focused on the mechanical property of fly ash concrete. It is no doubt that the use of high-volume fly ash as a partial replacement of cement is also one of the effect way to utilize fly ash. It is known that the compressive strength of fly ash concrete is lower than that of ordinary concrete at early age, especially for high-volume fly ash concrete. It is urgent for engineers to consider the compressive strength of high-volume fly ash concrete at different curing age. In this review, the compressive strength of high-volume fly ash concrete in various literature was reported and then analyzed. Furthermore, the proposal of the utilization of high-volume fly ash concrete is provided.

Effect of Curing System on Mechanical Property of Slag-Based Geopolymer

2011 ◽  
Vol 250-253 ◽  
pp. 3372-3376 ◽  
Author(s):  
Qing Wang ◽  
Xin Tu ◽  
Zhao Yang Ding ◽  
Zhi Tong Sui
Keyword(s):  
Mechanical Properties ◽  
Mechanical Property ◽  
Compressive Strength ◽  
Portland Cement ◽  
Curing Temperature ◽  
Early Age ◽  
Curing Time ◽  
Commercial Applications ◽  
The Ideal

Geopolymer has been gradually attracting world attention as a potentially revolutionary material that is one of the ideal substitutes of Portland cement, and fundamental studies on geopolymer are increased rapidly because of its potential commercial applications. However, little work has been done in the field of curing system of geopolymer. In this paper, influence of curing temperature, curing time and curing humidity on the mechanical properties of slag-based geopolymer was studied by using the compressive strength as benchmark parameter. Results have shown that the early age compressive strength of geopolymer increased and the long-term compressive strength decreased at first and then increased as the curing temperature increased, 80°C was the best curing temperature. With prolonging the curing time, it was found that the compressive strength of early age of geopolymer reached the maximum ( 116.3 MPa for 1d, 97.5 MPa for 3d) as the curing time was 12h, and that of 28d geopolymer was 91.3 MPa as the curing time was 10h. It was also found that the compressive strength of geopolymer reduced evidently as the humidity increased.

Evaluation on the Compressive Strength of Concrete Incorporating High Volume Blast-Furnace Slag Subjected to Initial Frost Damage

2011 ◽  
Vol 121-126 ◽  
pp. 2440-2444 ◽  
Author(s):  
Kyung Taek Koh ◽  
Gum Sung Ryu ◽  
Ki Hong Ahn ◽  
Chun Jin Park ◽  
Jang Hwa Lee
Keyword(s):  
Compressive Strength ◽  
Blast Furnace ◽  
Blast Furnace Slag ◽  
High Volume ◽  
Frost Damage ◽  
Early Age ◽  
Term Strength ◽  
Water Curing ◽  
Furnace Slag

Construction works that uses concrete incorporating a high volume of blast-furnace slag (BFS) during the winter season increases the risk of being subjected to initial frost damage as it noticeably delays setting and hardening. Assuming that the concrete incorporating a high volume of BFS was affected by freezing at an early age during the winter conditions, this study is to investigate the effect of strength degradation by early freezing and curing methods on compressive strength. As a result, freezing at early age highly degraded the compressive strength regardless of the types of concrete. After influenced by initial frost damage, water curing at 5°C improved the long-term strength and water curing at 30°C enhanced the long-term strength as well as the early strength.

KUBOTA KNC-03

Alloy Digest ◽  
2010 ◽  
Vol 59 (1) ◽  
Keyword(s):  
Compressive Strength ◽  
High Temperature ◽  
Physical Properties ◽  
Tensile Properties ◽  
High Strength ◽  
Temperature Performance ◽  
Resistance To Oxidation

Abstract Kubota KNC-03 is a grade with a combination of high strength and excellent resistance to oxidation. These properties make this alloy suitable for long-term service at temperature up to 1250 deg C (2282 deg F). This datasheet provides information on physical properties, hardness, elasticity, tensile properties, and compressive strength as well as creep. It also includes information on high temperature performance as well as casting and joining. Filing Code: Ni-676. Producer or source: Kubota Metal Corporation, Fahramet Division. See also Alloy Digest Ni-662, April 2008.

Anticancer Effects & Comparative Study of Thymoquinone, Cordyceps, Spirulina, Ganoderma Lucidium, Poria Cocos, and Lion’s Mane on Human Nasal Cancer Cells (RPMI-2650)

2020 ◽  
pp. 62-78
Author(s):  
سعيد مزعل موازي ◽  
يحيى فائق حسين ◽  
عبد المنعم دولاني ◽  
سيف يوسف عبدالله السويدي
Keyword(s):  
Term Treatment ◽  
Epithelial Cell Line ◽  
Anticancer Effect ◽  
Short Term Treatment ◽  
Poria Cocos ◽  
Nasal Cancer ◽  
Antineoplastic Effect ◽  
Long Term Treatment ◽  
High Concentrations

Recently, many studies have been conducted to discover or improve cancers treatment. The current study aims to investigate the anticancer effect of thymoquinone, cordyceps, spirulina, ganoderma lucidium, poria cocos, and lion’s mane in four different concentrations 4, 8, 16, and 32 ug (equivalent to 1 mg/mL) in two different time treatments (48 and 96 hours) on human nasal epithelial cell line RPMI 2650. By using cell culture cytotoxicity techniques and assay, the highest anticancer effect on RPMI 2650 was obtained by thymoquinone. The lowest anticancer effect was demonstrated by poria cocos and cordyceps. However, these two medications showed higher anticancer effect when given in short-term treatment (48 hours) compared to long-term treatment (96 hours). Ganoderma lucidium and spirulina showed better impact than poria cocos, cordyceps, and lion’s mane in term of cells cytotoxicity. Mild to moderate antineoplastic effect was seen by utilizing lion’s mane treatment compared other drugs. Therefore, adopting a long-term treatment of high concentrations and doses of thymoquinone, cordyceps, spirulina, ganoderma lucidium, poria cocos, and lion’s mane can be more effective in the treatment of nasal cancer. In conclusion, these drugs were found to be a promising cancer remedy; therefore, they can be utilized as alternative treatment for nasal cancer or any other type of cancer therapy.

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