Tentative Optimum Proportion of Supplementary Cementitious Materials in Blended Cement to Perform Better under Tannery Wastewater

2018 ◽  
Vol 937 ◽  
pp. 107-113
Author(s):  
Samina Samrose ◽  
Saifa Anzum ◽  
Samira Mahmud ◽  
Tanvir Manzur
Keyword(s):  
Compressive Strength ◽  
Fly Ash ◽  
Blended Cement ◽  
Cementitious Materials ◽  
Supplementary Cementitious Materials ◽  
Effluent Treatment ◽  
Tannery Wastewater ◽  
Wastewater Sample ◽  
Supplementary Cementitious Material ◽  
Optimum Proportion

The present research studies the compressive strength of cement mortar cubes prepared from different proportions of supplementary cementitious materials (Fly Ash and Slag) in blended cement. This research aims to find the tentative optimum composition of supplementary cementitious material that shows better performance under tannery wastewater condition, such as that in effluent treatment plants. Synthetic tannery wastewater was simulated in laboratory after collecting wastewater sample from local tannery industry. Eight types of cement compositions (varying supplementary materials proportions) have been chosen. Compressive strength test has been conducted on mortar cubes over a period of three months. Test results revealed that slag addition had shown significantly stronger effects than that of fly ash addition. Also, the combined effect of fly ash and slag and their order of variation on strength were studied. The observations made from this research will be helpful for selection of blended cement proportions in future structures exposed to similar severe conditions.

Suitability of Cordia millenii Ash Blended Cement in Concrete Production

2016 ◽  
Vol 22 ◽  
pp. 59-67 ◽  
Author(s):  
Olusola Emmanuel Babalola ◽  
Paul O. Awoyera
Keyword(s):  
Compressive Strength ◽  
Setting Time ◽  
Blended Cement ◽  
Cementitious Materials ◽  
Strength Properties ◽  
Supplementary Cementitious Materials ◽  
Sieve Analysis ◽  
Concrete Production ◽  
Alternative Materials ◽  
Concrete Control

Supplementary cementitious materials are most needed to enhance a sustainable development in poor communities. It is pertinent to investigate the suitability of such alternative materials for construction. The present study evaluates the strength characteristics of concrete made with varied proportion of Cordia millenii ash blended with Portland cement. Chemical composition of Cordia millenii and the setting time when blended with cement was determined. Other laboratory tests performed on Cordia millenii blended cement include: sieve analysis and specific gravity. Five replacement percentages of Cordia millenii (5%, 10%, 15%, and 20%) were blended with cement in concrete. Control specimens were also produced with only cement. Tests to determine the workability, air entrained, bulk density and compressive strength properties of the concrete were also conducted. Results obtained revealed that optimum Cordia millenii mix is 10%, which yielded the highest density and compressive strength in the concrete.

Current situation with the production and use of supplementary cementitious materials (SCMs) in concrete construction in Canada

2005 ◽  
Vol 32 (1) ◽  
pp. 129-143 ◽  
Author(s):  
Nabil Bouzoubaâ ◽  
Benoît Fournier
Keyword(s):  
Fly Ash ◽  
Silica Fume ◽  
Blended Cement ◽  
Cementitious Materials ◽  
Current Situation ◽  
Supplementary Cementitious Materials ◽  
Market Demand ◽  
Granulated Blast Furnace Slag ◽  
The Us ◽  
Economic Barriers

The data gathered on the current situation of supplementary cementing materials (SCMs) in Canada have shown that around 524 000, 347 000, and 37 000 t of fly ash, ground granulated blast furnace slag (GGBFS), and silica fume were used in cement and concrete applications in 2001, respectively, which represents 11%, 90%, and 185% of the quantity produced. The remaining 10% of GGBFS produced was used in the US, and 17 000 t of silica fume were imported from the US and Norway to meet market demand. Fly ash appears to be the only material that is underused and that represents a potential for increased use of SCMs in Canada. For the GGBFS, the quantity produced can be increased if the demand increases. This investigation has shown, however, that there are policy, technical, and economic barriers to the increased use of SCMs in Canada. Some solutions were proposed to overcome these barriers and are summarized in the conclusions of the paper.Key words: fly ash, slag, silica fume, concrete, blended cement.

scholarly journals Key Factors Determining the Self-Healing Ability of Cement-Based Composites with Mineral Additives

Materials ◽  
2021 ◽  
Vol 14 (15) ◽  
pp. 4211
Author(s):  
Kamil Tomczak ◽  
Jacek Jakubowski ◽  
Łukasz Kotwica
Keyword(s):  
Compressive Strength ◽  
Fly Ash ◽  
Crack Width ◽  
Defect Formation ◽  
Cementitious Materials ◽  
The Self ◽  
Supplementary Cementitious Materials ◽  
Self Healing ◽  
Key Factors ◽  
Important Indicator

This paper reveals the relationships between key factors that determine the ability of cementitious composites to self-heal autogenously and specific measures for quantifying the effects of this process. The following material factors: water-to-binder ratio (w/b), uniaxial compressive strength and age of the composite at the time of defect formation were considered, as well as the method and degree of damage to the tested material. The subjects of this study were mortars and concretes in which Portland cement was partially replaced, to varying degrees, with mechanically activated fluidized bed combustion fly ash (MAFBC fly ash) and siliceous fly ash. The samples were subjected to three-point bending or cyclic compression tests after 14 or 28 days of aging, in order to induce defects and then cured in water for 122 days. Microscopic (MO) and high-resolution scanning (HRS) observations along with computer image processing techniques were used to visualize and quantify the changes occurring in the macro-crack region near the outer surface of the material during the self-sealing process. Techniques based on the measurement of the ultrasonic pulse velocity (UPV) allowed the quantification of the changes occurring inside the damaged materials. Mechanical testing of the composites allowed quantification of the effects of the activity of the binder-supplementary cementitious materials (SCMs) systems. The analysis of the results indicates a significant influence of the initial crack width on the ability to completely close the cracks; however, there are repeated deviations from this rule and local variability of the self-sealing process. It has been shown that the compressive strength of a material is an important indicator of binder activity concerning crack width reduction due to self-sealing. Regardless of the crack induction method, the internal material changes caused by self-sealing are dependent on the degree of material damage.

scholarly journals Influence of supplementary cementitious materials on hydration and microstructure development of concrete

2019 ◽  
Vol 1 (1) ◽  
pp. 43-44
Keyword(s):  
Fly Ash ◽  
Portland Cement ◽  
Cementitious Materials ◽  
Supplementary Cementitious Materials ◽  
Cement Clinker ◽  
Hydration Kinetics ◽  
Supplementary Cementitious Material ◽  
Industrial Manufacturing ◽  
Portland Cement Clinker ◽  
By Products

Several supplementary cementitious materials (SCM) were blended with Portland cement clinker in order to produce more sustainable binders. The use of such materials, where no additional clinkering process is involved, leads to a significant reduction in CO2 emissions per ton of cementitious materials (grinding, mixing and transport of concrete and use very little energy compared to the clinkering process) and is a means to (re)utilize by-products of industrial manufacturing processes. Fly ash, for example, is the most commonly used supplementary cementitious material. The blending of Portland cement with fly ash results in the reduction of the total amount of portlandite in the hydrated mixture [1-4], somewhat less pronounced than for silica fume as: the reactivity of fly ash is very limited and as the CaO in the fly ash is an additional source of calcium [5]. Since fly ash particles are more spherical in shape than cement particles, workability and pumpability can be improved, by adding fly ash, also, fly ashes can cause low early strengthening. In this paper, the effects of Fly-ash as SCM’s on microstructure and hydration kinetics are studied.

scholarly journals Comparison of the influence of silica-rich supplementary cementitious materials on cement mortar composites: Mechanical and microstructural assessment

2021 ◽  
Author(s):  
Ozer Sevim ◽  
Cagrı Goktug Sengul
Keyword(s):  
Compressive Strength ◽  
Fly Ash ◽  
Cement Mortar ◽  
Bottom Ash ◽  
Cementitious Materials ◽  
Maximum Strength ◽  
Supplementary Cementitious Materials ◽  
Microstructural Properties ◽  
Cement Production ◽  
Mechanical And Microstructural Properties

Abstract The silica-rich supplementary cementitious materials (SCMs) are the key components of mechanical and microstructural properties. The use of SCMs results in improving the mechanical and microstructural properties and decreasing the environmental burden caused by cement production. In this regard, this paper reports a study to compare the influence of silica-rich supplementary cementitious materials (slag, fly ash, and bottom ash) having similar Blaine fineness on cement mortar composites in terms of mechanical and microstructural properties. First, supplementary cementitious materials (slag, fly ash, and bottom ash) were ground at similar cement Blaine fineness (~ 3300 cm2/g) and then by replacing 5% and 20% with cement, the 7-, 28-, 90-day mechanical and microstructural properties of cement mortar composites incorporating SCMs were examined. As a result, it was observed that the compressive strength and microstructural properties of cement mortar composites incorporating slag gave maximum strength and microstructural properties according to samples with fly ash and bottom ash having similar fineness and this will decrease the required amount of cement for the target properties by using slag, thus the number of CO2 emitted to nature will also decrease.

Understanding the effect of recycled concrete aggregate and cementitious materials on concrete's fire resistance

2021 ◽  
Vol ahead-of-print (ahead-of-print) ◽  
Author(s):  
Mohammed Ahmed Abed ◽  
Eva Lubloy
Keyword(s):  
Fly Ash ◽  
High Temperatures ◽  
Fire Resistance ◽  
Blended Cement ◽  
Cementitious Materials ◽  
Recycled Concrete ◽  
Supplementary Cementitious Materials ◽  
Concrete Aggregate ◽  
Recycled Concrete Aggregate ◽  
Content Type

PurposeFire can severely affect concrete structures and with knowledge of the properties of materials, the damage can be assessed. Aggregate, cement matrix and their interaction are the most important components that affect concrete behaviour at high temperatures. The effect of incorporating recycled concrete aggregate or cementitious materials, namely, cement type and pulverized fly ash, are reviewed to provide a better understanding of their involvement in fire resistance.Design/methodology/approachMore investigation research is needed to understand the fire resistance of such sustainable concrete that was already constructed. The present study illustrates the effect of using recycled concrete aggregate and cementitious materials on the fire resistance of concrete. To do so, a literature review was conducted and relevant data were collected and presented in a simple form. The author's selected research findings, which are related to the presents study, are also presented and discussed.FindingsRecycled concrete aggregate enhances the concrete behaviour at high temperatures when it substitutes the natural aggregate by reasonable substitution (more than 25–30%). It also almost eliminates the possibility of spalling. Moreover, utilizing both supplementary cementitious materials with recycled concrete aggregate can improve the fire resistance of concrete. The incorporation of pulverized fly ash and slag in Portland cement or blended cement can generally keep the mechanical properties of concrete at a higher level after heating to a high temperature.Originality/valueRecycled concrete aggregate enhances the concrete behaviour at high temperatures when it substitutes the natural aggregate by reasonable substitution (more than 25–30%). It also almost eliminates the possibility of spalling. Moreover, utilizing both supplementary cementitious materials with recycled concrete aggregate can improve the fire resistance of concrete. The incorporation of pulverized fly ash and slag in Portland cement or blended cement can generally keep the mechanical properties of concrete at a higher level after heating to a high temperature.

Durability of Sustainable Self-Consolidating Concrete

2018 ◽  
Vol 765 ◽  
pp. 285-289
Author(s):  
Osama Ahmed Mohamed ◽  
Waddah Al Hawat ◽  
Omar Fawwaz Najm
Keyword(s):  
Compressive Strength ◽  
Fly Ash ◽  
Silica Fume ◽  
Cementitious Materials ◽  
Chloride Penetration ◽  
Supplementary Cementitious Materials ◽  
Test Results ◽  
Self Consolidating Concrete ◽  
Human Footprint ◽  
Granulated Blast Furnace Slag

Supplementary cementitious materials such as fly ash, silica fume and ground granulated blast furnace slag (GGBS) have been used widely to partially replace cement in producing self-consolidating concrete (SCC). The production of cement is associated with emission of significant amounts of CO2 and increases the human footprint on the environment. Fly ash, silica fume, and GGBS are recycled industrial by-products that also impart favorable fresh and hardened properties on concrete. This study aims to assess the effect of the amounts of fly ash and silica fume on strength and chloride penetration resistance of concrete. Rapid Chloride Penetration Test (RCPT) was used to assess the ability of SCC to resist ingress of chlorides into concrete. SCC mixes with different dosages of fly ash and silica fume were developed and tested at different curing ages. Test results showed that replacing 20% of cement with fly ash produced the highest compressive strength of 67.96 MPa among all fly ash-cement binary mixes. Results also showed that replacing15% of cement with silica fume produced the highest compressive strength of 95.3 MPa among fly ash-cement binary mixes. Using fly ash and silica fume consistently increased the concrete resistance to chloride penetration at the early ages. Silica fume at all dosages results in low or very low levels of chloride penetration at all curing ages of concrete.

scholarly journals Physical and Mechanical Properties of High-Strength Concrete Modified with Supplementary Cementitious Materials after Exposure to Elevated Temperature up to 1000 °C

Materials ◽  
2020 ◽  
Vol 13 (3) ◽  
pp. 532 ◽  
Author(s):  
Jianwei Zhou ◽  
Dong Lu ◽  
Yuxuan Yang ◽  
Yue Gong ◽  
Xudong Ma ◽  
...  
Keyword(s):  
Compressive Strength ◽  
Fly Ash ◽  
Physical Properties ◽  
Water Absorption ◽  
High Strength Concrete ◽  
Elevated Temperatures ◽  
High Strength ◽  
Cementitious Materials ◽  
Supplementary Cementitious Materials ◽  
Strength Concrete

This paper presents the experimental findings of a study on the influence of combining usage of supplementary cementitious materials (SCMs) on the performance of high-strength concrete (HSC) subjected to elevated temperatures. In this study, four types of HSC formulations were prepared: HSC made from cement and fly ash (FA), HSC made from cement and ultra-fine fly ash (UFFA), HSC made from cement and UFFA-metakaolin (MK), and HSC made from cement and FA-UFFA-MK. Mechanical and physical properties of HSC subjected to high temperatures (400, 600, 800, and 1000 °C) were studied. Furthermore, the relation between residual compressive strength and physical properties (loss mass, water absorption, and porosity) of HSC was developed. Results showed that the combined usage of SCMs had limited influence on the early-age strength of HSC, while the 28-d strength had been significantly affected. At 1000 °C, the residual compressive strength retained 18.7 MPa and 23.9 MPa for concretes containing 30% UFFA-5% MK and 10% FA-20% UFFA-5% MK, respectively. The specimen containing FA-UFFA-MK showed the best physical properties when the temperature raised above 600 °C. Combined usage of SCMs (10% FA-20% UFFA-5% MK) showed the lowest mass loss (9.2%), water absorption (10.9%) and porosity (28.6%) at 1000 °C. There was a strongly correlated relation between residual strength and physical properties of HSC exposed to elevated temperatures.

scholarly journals Copper Slag Blended Cement: An Environmental Sustainable Approach for Cement Industry in India

2016 ◽  
Vol 11 (1) ◽  
pp. 186-196
Author(s):  
Jagmeet Singh ◽  
Jaspal Singh ◽  
Manpreet Kaur
Keyword(s):  
Blended Cement ◽  
Copper Slag ◽  
Cementitious Materials ◽  
Strength Test ◽  
Cementitious Material ◽  
Cement Industry ◽  
Supplementary Cementitious Materials ◽  
Material Strength ◽  
Test Results ◽  
Supplementary Cementitious Material

Indian cement industry is facing environmental issue of emission of carbon dioxide (CO2), a greenhouse gas. Blended cements including supplementary cementitious materials are substitute of Portland cement to reduce CO2 emission. The present paper investigates theappropriateness of copper slag (CS) as supplementary cementitious material. Strength properties and hydration of mixes were determined at different replacement levels of CS with cement. Compressive, flexural and tensile strength of each mix was found out at different curing periods. The hydration of cement was investigated through X-ray diffraction (XRD). The strength test results showed that substitution of up to 20% of CS can significantly replace Portland cement.XRD test results were corresponding to strength test results. The present study encourages the utilization of CS as supplementary cementitious material to make economical and environmentally sustainable blended cement

scholarly journals The Influence and Application of Slag, Fly Ash, and Limestone Flour on Compressive Strength of Concrete Based on the Concrete Compressive Strength Development over Time (CCSDOT) Model

2020 ◽  
Vol 10 (10) ◽  
pp. 3572
Author(s):  
Jian Zheng ◽  
Guohua Liu
Keyword(s):  
Compressive Strength ◽  
Fly Ash ◽  
Cementitious Materials ◽  
Supplementary Cementitious Materials ◽  
Strength Development ◽  
Mix Proportion ◽  
Practical Engineering ◽  
Compressive Strength Development ◽  
Compressive Strength Of Concrete ◽  
Selection Of

Concrete and cement have been widely used in past decades as a result of urbanization. More and more supplementary cementitious materials are adopted in concrete because its production complements environmental conservation. The influence of slag, fly ash, limestone, etc., on compressive strength of concrete is of interest to engineers worldwide. Many previous studies were specific to certain engineering or certain experiments that could not reveal the nature of the influence of the three supplementary cementitious materials on concrete’s compressive strength. The research concerning the influence of two or more kinds of supplementary cementitious materials on concrete’s compressive strength is still unclear. Moreover, there is a lack of clarity on the optimum proportion of one or more certain cementitious materials in practical engineering or experiments. To overcome these problems, this study adopts the concrete compressive strength development over time (CCSDOT) model, which generates an explicit formula to conduct quantitative research based on extensive data. The CCSDOT model performs well in fitting the compressive strength development of concrete containing cement, slag, fly ash, and limestone flour. The results reveal the nature of the influence of the three supplementary cementitious materials on concrete’s compressive strength through the parameter analysis in the model. Two application cases are analyzed concerning the selection of the three supplementary cementitious materials and design of concrete mix proportion for practical engineering. It is concluded that the CCSDOT model and the method in this study can possibly provide guidance on both the selection of supplementary cementitious materials and the design of optimal concrete mix proportion for practical engineering. Therefore, the study is highly essential and useful.

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