Porosity Evaluation of Alternative Materials Based on Portland Cement

2014 ◽  
Vol 1000 ◽  
pp. 314-317 ◽  
Author(s):  
Ladislav Pařízek ◽  
Eva Bartoníčková ◽  
Vlastimil Bílek Jr. ◽  
Jiří Kratochvíl
Keyword(s):  
Fly Ash ◽  
Portland Cement ◽  
Coal Combustion ◽  
Mercury Intrusion Porosimetry ◽  
Raw Materials ◽  
High Energy ◽  
Energy Requirements ◽  
Mercury Intrusion ◽  
Secondary Raw Materials ◽  
Alternative Materials

High energy requirements and the resulting economic demands due to the production of Portland cement leads to tendency to replace a portion of cement with secondary raw materials or to use other alternative binders. Among the commonly used cements replacements is currently fly ash which is produced during the coal combustion. In this paper the influence of cement/ash ratio in a paste on paste’s porosity is investigated using mercury intrusion porosimetry.

scholarly journals Editorial for Special Issue “Minerals and Elements from Fly Ash and Bottom Ash as a Source of Secondary Raw Materials”

Minerals ◽  
2021 ◽  
Vol 11 (5) ◽  
pp. 438
Author(s):  
Alexandra Guedes ◽  
Bruno Valentim
Keyword(s):  
Fly Ash ◽  
Raw Materials ◽  
Bottom Ash ◽  
Resource Efficiency ◽  
Special Issue ◽  
Secondary Raw Materials ◽  
Alternative Materials

The sustainability of primary resources depends on recycling, resource efficiency and the search for alternative materials [...]

The Influence of Particle Size of Cement and Different Additives on the Properties of Portland Cement Pastes

2016 ◽  
Vol 851 ◽  
pp. 104-109 ◽  
Author(s):  
Pavel Šiler ◽  
Iva Kolářová ◽  
Tomáš Sehnal ◽  
Roman Snop ◽  
Tomáš Opravil ◽  
...  
Keyword(s):  
Particle Size ◽  
Fly Ash ◽  
Portland Cement ◽  
Raw Materials ◽  
Cement Pastes ◽  
Secondary Raw Materials ◽  
Granulated Blast Furnace Slag ◽  
Concrete Production ◽  
Effect Of Particle Size ◽  
Effective Use

The consumption of concrete as a building material is still increasing over the world. Concrete production is closely associated with CO2 and other greenhouse gases emissions. The reduction of these emissions can be achieved by a higher utilization of secondary raw materials in cement mixtures. Particle size is an important factor for more effective use of these materials. This work is focused on the calorimetric determination of the effect of particle size of cement, finely ground granulated blast furnace slag (GBFS), high-temperature fly ash (FA) and fluidized fly ash (FFA) on the Portland cement hydration. Effect of particle size on the hydration of pure cement pastes and pastes with the addition of secondary raw materials is monitored by isoperibolic calorimetry. Other part of this work is aimed on the mechanical properties of resulting materials. The flexural strength and compressive strength were observed after 1, 7 and 28 days of curing.

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

Materials ◽  
2020 ◽  
Vol 13 (4) ◽  
pp. 1015 ◽  
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.

Preparation of Alternative Hydraulic Binder Based on Secondary Raw Materials

2014 ◽  
Vol 1000 ◽  
pp. 12-15
Author(s):  
Jiří Švec ◽  
Tomáš Opravil ◽  
Jiří Másilko
Keyword(s):  
Portland Cement ◽  
Raw Materials ◽  
Construction Materials ◽  
High Volume ◽  
Point Of View ◽  
Hydraulic Lime ◽  
Combustion Gases ◽  
Secondary Raw Materials ◽  
Hydraulic Binder ◽  
Massive Scale

Reusing and recycling of secondary raw materials from high-volume industrial productions (especially form construction materials and binders fabrications) is very important way of conserving environment and it is also interesting from the economical point of view. The production of common hydraulic binders, especially Portland cement, burdens the environment with considerable amount of combustion gases and consumes energy in massive scale. Alternative (low – energy) binder can be used as Portland cement substitution in applications with lower mechanical properties requirements. Mined limestone wash sediments contain large amount of clay components, but there is also indispensable share of fine calcite. This composition makes these sediments a promising material for the preparation of hydraulic binders as Roman cement or hydraulic lime.

scholarly journals Influence of mineral additions on the microstructure of concrete in chloride environment

2018 ◽  
Vol 1 (1) ◽  
pp. 283-292
Author(s):  
Walid Fouad Edris ◽  
Safwat Abdelkader ◽  
Encarnacion Reyes Pozo ◽  
Amparo Moragues Terrades
Keyword(s):  
Portland Cement ◽  
Blast Furnace Slag ◽  
Mercury Intrusion Porosimetry ◽  
Gas Permeability ◽  
Chloride Diffusion ◽  
Mercury Intrusion ◽  
Experimental Campaign ◽  
Mineral Additions ◽  
Chloride Environment ◽  
Furnace Slag

In this work we have designed an experimental campaign with four different dosages of concrete to study the influence of the principal additions used in marine environments. The effect of material composition [Sulfate Resistant Portland Cement (SRPC), Blast Furnace Slag Portland Cement (BFSPC), Silica Fume (SF) and Fly Ash (FA) with four different mix designs] was performed by means of differential thermal analysis (DTA), mercury intrusion porosimetry (MIP), gas permeability, chloride diffusion and mechanical properties of concrete. In order to simulate the aggressiveness of the marine environment the concretes were immersed in a sodium chloride solution with a concentration of 1 molar during different times of 182, 365 and 546 days. According to the results obtained, the SRPC and SRPC+FA samples suffered the highest rise in permeability, porosity and chloride diffusion, and the greatest loss in compressive strength

scholarly journals Analysis of Content of Selected Critical Elements in Fly Ash

2016 ◽  
Vol 62 (1) ◽  
pp. 31-36 ◽  
Author(s):  
Dorota Makowska ◽  
Faustyna Wierońska
Keyword(s):  
Fly Ash ◽  
Coal Combustion ◽  
Power Plants ◽  
Raw Materials ◽  
Coal Fly Ash ◽  
New Mineral ◽  
The European Union ◽  
Cobalt Chromium ◽  
Critical Elements ◽  
Potential Source

AbstractPursuant to the new mineral policy of the European Union, searching for new sources of raw materials is required. Coal fly ash has long been considered as a potential source of a number of critical elements. Therefore, it is important to monitor the contents of the critical elements in fly ash from coal combustion. The paper presents the results of examinations of the contents of selected elements, i.e. beryllium, cobalt, chromium and germanium in fly ash from Polish power plants. The results of the conducted investigations indicate that the examined ash samples from bituminous coal combustion cannot be treated as a potential source of the analysed critical elements. The content of these elements in ash, though slightly higher than their average content in the sedimentary rocks, is, however, not high enough to make their recovery technologically and economically justified at this moment.

scholarly journals Evaluation of the Ecotoxicological Potential of Fly Ash and Recycled Concrete Aggregates Use in Concrete

2020 ◽  
Vol 10 (1) ◽  
pp. 351 ◽  
Author(s):  
Patrícia Rodrigues ◽  
José D. Silvestre ◽  
Inês Flores-Colen ◽  
Cristina A. Viegas ◽  
Hawreen H. Ahmed ◽  
...  
Keyword(s):  
Fly Ash ◽  
Portland Cement ◽  
Daphnia Magna ◽  
Raw Materials ◽  
Construction Materials ◽  
Recycled Concrete ◽  
Experimental Program ◽  
Concrete Aggregates ◽  
Recycled Concrete Aggregates ◽  
Natural Aggregates

This study applies a methodology to evaluate the ecotoxicological potential of raw materials and cement-based construction materials. In this study, natural aggregates and Portland cement were replaced with non-conventional recycled concrete aggregates (RA) and fly ash (FA), respectively, in the production of two concrete products alternative to conventional concrete (used as reference). The experimental program involved assessing both the chemical properties (non-metallic and metallic parameters) and ecotoxicity data (battery of tests with the luminescent bacterium Vibrio fischeri, the freshwater crustacean Daphnia magna, and the yeast Saccharomyces cerevisiae) of eluates obtained from leaching tests of RA, FA, and the three concrete mixes. Even though the results indicated that RA and FA have the ability to release some chemicals into the water and induce its alkalinisation, the respective eluate samples presented no or low levels of potential ecotoxicity. However, eluates from concrete mixes produced with a replacement ratio of Portland cement with 60% of FA and 100% of natural aggregates and produced with 60% of FA and 100% of RA were classified as clearly ecotoxic mainly towards Daphnia magna mobility. Therefore, raw materials with weak evidences of ecotoxicity could lead to the production of concrete products with high ecotoxicological potential. Overall, the results obtained highlight the importance of integrating data from the chemical and ecotoxicological characterization of materials’ eluate samples aiming to assess the possible environmental risk of the construction materials, namely of incorporating non-conventional raw materials in concrete, and contributing to achieve construction sustainability.

Relationships for Size and Dispersion of Pores with Mix Factors for Cement Sand Mortar

2016 ◽  
Vol 866 ◽  
pp. 37-42
Author(s):  
B. Kondraivendhan
Keyword(s):  
Portland Cement ◽  
Ordinary Portland Cement ◽  
Mercury Intrusion Porosimetry ◽  
Mercury Intrusion ◽  
Different Types ◽  
Effect Of Age

In this study the effect of age, w/c ratio on mean distribution radius and dispersion of pores in Ordinary Portland Cement (OPC) sand mortar was determined through Mercury Intrusion Porosimetry (MIP) test. For this purpose the cement sand mortar specimens were prepared from two different types of OPC with varied w/c ratios such as 0.2, 0.3, 0.4, 0.5 and 0.6 and tested at different curing ages from 1 day to 90 days. Separate relationships relating the mix parameters such as w/c ratio and age with mean distribution radius (r0.5) and coefficient (d) representing dispersion of pores, are developed for OPC sand mortars.

Shrinkage of Blended Cement Pastes with Mineral Additions

2013 ◽  
Vol 539 ◽  
pp. 55-59
Author(s):  
Yi Chen ◽  
Wu Yao ◽  
Dan Jin
Keyword(s):  
Fly Ash ◽  
Silica Fume ◽  
Cement Paste ◽  
Mercury Intrusion Porosimetry ◽  
Construction Materials ◽  
Blended Cement ◽  
Cement Pastes ◽  
Mercury Intrusion ◽  
Mineral Additions ◽  
By Products

Mineral additions such as fly ash and silica fume are industrial by products, and play an important role in properties improvement for construction materials. In this work, the shrinkage of cement paste blended with fly ash and silica fume by different substitute ratio was studied. Pore structures of specimens at different ages were determined by mercury intrusion porosimetry (MIP) and shrinkage deformation was measured by standard shrinkage tests. The effects of mineral addtions on shrinkage were discussed. The results show that the fly ash was significantly effective on shrinkage at early ages. Based on the research, several suitable advices were offered to optimize the performances of materials and reduce the shrinkage.

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