Solidification/stabilization of arsenic containing solid wastes using portland cement, fly ash and polymeric materials

Conditioning of sludges improves dewatering characteristics and reduces the quantity of sludge to be handled. Anaerobic digested sludge collected from a sewage treatment plant contained 1.8% to 8% oil. The increase of specific resistance and capillary suction time (CST) with increasing oil content observed in these samples indicates the interference of oil in dewatering. It has been found that addition of municipal solid wastes incinerator fly ash decreases the specific resistances and capillary suction times of oily sludges rapidly up to 3% dosage. Beyond 3% fly ash, the decrease is less significant and the solids content in the sludge cake increases. This optimum dosage remains the same for sludges with varying oil contents from 1.8% to 12%. The total suspended solids of filtrate decreases with fly ash dosage but the toxic concentrations of heavy metals increases considerably. However at the optimum dosage of 3%, concentrations of heavy metals are within the limits for discharging into the sewers. The correlations of CST with the dewatering characteristics such as specific resistance, filter yield and corrected filter yield are established. These correlations can be used to obtain a quick prediction on dewaterability.

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Strength Development and Elemental Distribution of Dolomite/Fly Ash Geopolymer Composite under Elevated Temperature

Materials ◽

10.3390/ma13041015 ◽

2020 ◽

Vol 13 (4) ◽

pp. 1015 ◽

Cited By ~ 4

Author(s):

Emy Aizat Azimi ◽

Mohd Mustafa Al Bakri Abdullah ◽

Petrica Vizureanu ◽

Mohd Arif Anuar Mohd Salleh ◽

Andrei Victor Sandu ◽

...

Keyword(s):

Elevated Temperature ◽

Fly Ash ◽

Portland Cement ◽

Ordinary Portland Cement ◽

Raw Materials ◽

Liquid Sodium ◽

Strength Development ◽

Elemental Distribution ◽

Distribution Analysis ◽

Geopolymer Composites

A geopolymer has been reckoned as a rising technology with huge potential for application across the globe. Dolomite refers to a material that can be used raw in producing geopolymers. Nevertheless, dolomite has slow strength development due to its low reactivity as a geopolymer. In this study, dolomite/fly ash (DFA) geopolymer composites were produced with dolomite, fly ash, sodium hydroxide, and liquid sodium silicate. A compression test was carried out on DFA geopolymers to determine the strength of the composite, while a synchrotron Micro-Xray Fluorescence (Micro-XRF) test was performed to assess the elemental distribution in the geopolymer composite. The temperature applied in this study generated promising properties of DFA geopolymers, especially in strength, which displayed increments up to 74.48 MPa as the optimum value. Heat seemed to enhance the strength development of DFA geopolymer composites. The elemental distribution analysis revealed exceptional outcomes for the composites, particularly exposure up to 400 °C, which signified the homogeneity of the DFA composites. Temperatures exceeding 400 °C accelerated the strength development, thus increasing the strength of the DFA composites. This appears to be unique because the strength of ordinary Portland Cement (OPC) and other geopolymers composed of other raw materials is typically either maintained or decreases due to increased heat.

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Heat of hydration of Portland Cement–Metakaolin–Fly ash (PC–MK–PFA) blends

Cement and Concrete Research ◽

10.1016/j.cemconres.2008.01.004 ◽

2008 ◽

Vol 38 (6) ◽

pp. 832-840 ◽

Cited By ~ 79

Author(s):

David G. Snelson ◽

Stan Wild ◽

Martin O'Farrell

Keyword(s):

Fly Ash ◽

Portland Cement ◽

Heat Of Hydration

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Mössbauer, DTA and XRD study of Portland cement blended with fly ash and silica fume

Construction and Building Materials ◽

10.1016/j.conbuildmat.2011.10.030 ◽

2012 ◽

Vol 29 ◽

pp. 33-41 ◽

Cited By ~ 18

Author(s):

Vili Lilkov ◽

Ognyan Petrov ◽

Yana Tzvetanova ◽

Plamen Savov

Keyword(s):

Fly Ash ◽

Portland Cement ◽

Silica Fume ◽

Xrd Study

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Engineering properties of waste-based alkali activated concrete brick containing low calcium fly ash and rice husk ash: A comparison with traditional Portland cement concrete brick

Journal of Building Engineering ◽

10.1016/j.jobe.2021.103810 ◽

2021 ◽

pp. 103810

Author(s):

Sarah Fernando ◽

Chamila Gunasekara ◽

David W. Law ◽

M.C.M. Nasvi ◽

Sujeeva Setunge ◽

...

Keyword(s):

Fly Ash ◽

Portland Cement ◽

Rice Husk ◽

Rice Husk Ash ◽

Engineering Properties ◽

Portland Cement Concrete ◽

Cement Concrete ◽

Low Calcium ◽

Alkali Activated Concrete ◽

Alkali Activated

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A trial construction of high durability railway viaducts with local aggregates

IABSE Congress, New York, New York 2019: The Evolving Metropolis ◽

10.2749/newyork.2019.1917 ◽

2019 ◽

Author(s):

Kotaro Kawamura ◽

Joe Takemura ◽

Shigenobu Iguchi ◽

Tsutomu Yoshida ◽

Masashi Kobayashi

Keyword(s):

Fly Ash ◽

Side Effects ◽

Portland Cement ◽

Ordinary Portland Cement ◽

The Other ◽

Strength Concrete ◽

High Durability ◽

Sound Barrier ◽

Early Strength ◽

Structural Measure

<p>We are carrying out a construction project of new railroad viaducts. These new railroad viaducts are constructing using about 110,000 m<span>3</span> volume concrete. In this construction place, it is difficult for us to get low ASR-reactive aggregates and it is expected to be supplied with snowmelt water on the viaducts in winter. Then we tested ASR-reactive these local aggregates and found an effective mixed ratio of fly-ash is 20% of cement. On the other hand, various side effects were also expected by using fly-ash. For example, initial cracking due to contraction, early strength concrete, bleeding, etc. Therefore, we repeated various tests and examined and carried out a method that could ensure the same construction method and quality as when using ordinary Portland cement, even with fly-ash. Also, we adopted a structure that is unlikely to be affected by rainwater as a structural measure. For example, the entire adoption of a ramen type viaduct that has eliminated bearings, adoption of FRP sound barrier, etc. Then we made it possible to build highly durable railway viaducts by these various measures of materials and structures.</p>

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