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

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.

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Durability of Sustainable Self-Consolidating Concrete

Key Engineering Materials ◽

10.4028/www.scientific.net/kem.765.285 ◽

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.

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Effect of ground granulated blast funrnace slag and fly ash on strength, permeability, and under-water abrasion of fine-grained concrete

Transport and Communication Science Journal ◽

10.25073/tcsj.71.7.4 ◽

2020 ◽

Vol 71 (7) ◽

pp. 775-788

Author(s):

Quyet Truong Van ◽

Sang Nguyen Thanh

Keyword(s):

Fly Ash ◽

Concrete Strength ◽

Cementitious Materials ◽

Supplementary Cementitious Materials ◽

Chloride Permeability ◽

Cement Replacement ◽

Fine Grained ◽

Granulated Blast Furnace Slag ◽

Compressive Strength Test ◽

Economic Ground

The utilisation of supplementary cementitious materials (SCMs) is widespread in the concrete industry because of the performance benefits and economic. Ground granulated blast furnace slag (GGBFS) and fly ash (FA) have been used as the SCMs in concrete for reducing the weight of cement and improving durability properties. In this study, GGBFS at different cement replacement ratios of 0%, 20%, 40% and 60% by weight were used in fine-grained concrete. The ternary binders containing GGBFS and FA at cement replacement ratio of 60% by weight have also evaluated. Flexural and compressive strength test, rapid chloride permeability test and under-water abrasion test were performed. Experimental results show that the increase in concrete strength with GGBFS contents from 20% to 40% but at a higher period of maturity (56 days and more). The chloride permeability the under-water abrasion reduced with the increasing cement replacement by GGBFS or a combination of GGBFS and FA

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Study of Hydration and Microstructure of Mortar Containing Coral Sand Powder Blended with SCMs

Materials ◽

10.3390/ma13194248 ◽

2020 ◽

Vol 13 (19) ◽

pp. 4248

Author(s):

Xingxing Li ◽

Ying Ma ◽

Xiaodong Shen ◽

Ya Zhong ◽

Yuwei Li

Keyword(s):

Compressive Strength ◽

Portland Cement ◽

Silica Fume ◽

Dilution Effect ◽

Cementitious Materials ◽

Supplementary Cementitious Materials ◽

Limestone Powder ◽

Chemical Effect ◽

Granulated Blast Furnace Slag ◽

Coral Sand

The utilization of coral waste is an economical way of using concrete in coastal and offshore constructions. Coral waste with more than 96% CaCO3 can be ground to fines and combined with supplementary cementitious materials (SCMs) such as fly ash, silica fume, granulated blast furnace slag in replacing Portland cement to promote the properties of cement concrete. The effects of coral sand powder (CSP) compared to limestone powder (LSP) blended with SCMs on hydration and microstructure of mortar were investigated. The result shows CSP has higher activity than LSP when participating in the chemical reaction. The chemical effect among CSP, SCMs, and ordinary Portland cement (OPC) results in the appearance of the third hydration peak, facilitating the production of carboaluminate. CSP-SCMs mortar has smaller interconnected pores on account of the porous character of CSP as well as the filler and chemical effect. The dilution effect of CSP leads to the reduction of compressive strength of OPC-CSP and OPC-CSP-SCMs mortars. The synergic effects of CSP with slag and silica fume facilitate the development of compressive strength and lead to a compacted isolation and transfer zone (ITZ) in mortar.

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Production of Ultra-High-Performance Concrete with Low Energy Consumption and Carbon Footprint Using Supplementary Cementitious Materials Instead of Silica Fume: A Review

Energies ◽

10.3390/en14248291 ◽

2021 ◽

Vol 14 (24) ◽

pp. 8291

Author(s):

Mays A. Hamad ◽

Mohammed Nasr ◽

Ali Shubbar ◽

Zainab Al-Khafaji ◽

Zainab Al Masoodi ◽

...

Keyword(s):

Energy Consumption ◽

Silica Fume ◽

High Performance ◽

High Performance Concrete ◽

Cementitious Materials ◽

Supplementary Cementitious Materials ◽

Ultra High Performance Concrete ◽

Cement Production ◽

Granulated Blast Furnace Slag ◽

The Impact

The increase in cement production as a result of growing demand in the construction sector means an increase in energy consumption and CO2 emissions. These emissions are estimated at 7% of the global production of CO2. Ultra-high-performance concrete (UHPC) has excellent mechanical and durability characteristics. Nevertheless, it is costly and affects the environment due to its high amount of cement, which may reach 800–1000 kg/m3. In order to reduce the cement content, silica fume (SF) was utilized as a partial alternative to cement in the production of UHPC. Nevertheless, SF is very expensive. Therefore, the researchers investigated the use of supplementary cementitious materials cheaper than SF. Very limited review investigates addressed the impact of such materials on different properties of UHPC in comparison to that of SF. Thus, this study aims to summarize the effectiveness of using some common supplementary cementitious materials, including fly ashes (FA), ground granulated blast furnace slag (GGBS), metakaolin (MK) and rice husk ashes (RHA) in the manufacturing of UHPC, and comparing the performance of each material with that of SF. The comparison among these substances was also discussed. It has been found that RHA is considered a successful alternative to SF to produce UHPC with similar or even higher properties than SF. Moreover, FA, GGBS and MK can be utilized in combination with SF (as a partial substitute of SF) as a result of having less pozzolanic activity than SF.

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The Relationship between Cementitious Composition and Properties of Ultrahigh Strength Concrete

Advances in Civil Engineering ◽

10.1155/2021/5549161 ◽

2021 ◽

Vol 2021 ◽

pp. 1-8

Author(s):

Dehui Wang ◽

Zhiwen Zhang

Keyword(s):

Fly Ash ◽

Calcium Hydroxide ◽

Silica Fume ◽

Design Method ◽

Cementitious Materials ◽

Supplementary Cementitious Materials ◽

Strength Concrete ◽

Ultrahigh Strength ◽

Acceleration Period ◽

The Relationship

It is well known that supplementary cementitious materials (SCMs) have obvious effects on the properties of concrete. In order to understand the relationship between cementitious materials and properties of ultrahigh strength concrete (UHSC), the cementitious compositions of UHSC were designed by the simple-centroid design method. The effects of cementitious compositions on the properties of UHSC were investigated. It was found that the incorporation of silica fume (SF) improved the flowability and strength of UHSC, but it decreased the time of acceleration period, calcium hydroxide (CH) content, and porosity of UHSC at a certain content. The incorporation of fly ash (FA) increased the flowability, time of acceleration period, and porosity of UHSC, but it decreased the strength and CH content of UHSC. The relationships between cement, silica fume, and fly ash and the properties of UHSC were calculated based on the simple-centroid design method.

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Efficiency Concepts and Models that Evaluates the Strength of Concretes Containing Different Supplementary Cementitious Materials

Civil Engineering Journal ◽

10.28991/cej-2019-03091222 ◽

2019 ◽

Vol 5 (1) ◽

pp. 18 ◽

Cited By ~ 3

Author(s):

Rahul Biswas ◽

Baboo Rai

Keyword(s):

Fly Ash ◽

Silica Fume ◽

Research Work ◽

Cementitious Materials ◽

Mineral Admixture ◽

Supplementary Cementitious Materials ◽

Hardened Concrete ◽

Effective Utilization ◽

Natural Pozzolans ◽

Quantitative Understanding

The usage of Supplementary Cementitious Materials (SCM) is very much acknowledged due to the several improvements possible in the concrete composites, and because of the general economy. Research work till date suggests that utilization of SCMs enhance a significant number of the performance characteristics of the hardened concrete. The idea of efficiency can be utilized for comparing the relative performance of different pozzolans when incorporated into concrete. The efficiency concept, which was initially developed for fly ash, can be effortlessly connected to other advantageous s as well, such as silica fume, slag and natural pozzolans. A quantitative understanding of the efficiency of SCMs as a mineral admixture in concrete is essential for its effective utilization. The paper reviews the literature pertaining to the different efficiency concepts and models present to date that evaluates the strength of concretes containing different SCMs. This short survey demonstrates that there is a need for a superior comprehension of the SCMs in concrete for its powerful usage. Also, it is an effort directed towards a specific understanding of the efficiency of SCMs in concrete.

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

Journal of Structural Fire Engineering ◽

10.1108/jsfe-09-2021-0056 ◽

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.

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

Materials Science Forum ◽

10.4028/www.scientific.net/msf.937.107 ◽

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.

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Degradation of Shotcrete Materials Subjected to Sulfate and Chloride Attack in Varying Exposure Regimes

Advances in Civil Engineering ◽

10.1155/2021/7323934 ◽

2021 ◽

Vol 2021 ◽

pp. 1-11

Author(s):

Ruiqiang Zhao ◽

Lihao Xu ◽

Jun Yang ◽

Yang Zou ◽

Zhongya Zhang

Keyword(s):

Fly Ash ◽

Silica Fume ◽

Cementitious Materials ◽

Sulfate Attack ◽

Chloride Ions ◽

Supplementary Cementitious Materials ◽

Mineral Admixtures ◽

Exposure Condition ◽

Hydration Kinetics ◽

Partial Immersion

Durability of in situ shotcrete under external sulfate attack was investigated, taking into consideration the addition of mineral admixtures, along with the presence of chloride ions. Three water-to-binder ratios (w/b), i.e., 0.35, 0.45, and 0.55, and two types of supplementary cementitious materials (SCMs), namely, fly ash (FA) and silica fume (SF), were considered in the current study. Two different laboratorial immersion regimes (continuously full immersion and partial immersion with cycling temperature and relative humidity) were carried out to induce chemical/physical sulfate attack. Results show that loss of strength was the typical feature of chemical sulfate attack on shotcrete, while surface spalling dominated in deterioration caused by physical sulfate attack. The presence of chloride ions can globally mitigate these deteriorations. Meanwhile, the lower w/b ratio proved to be efficient in increasing the resistance to both sulfate attacks. Adding fly ash (FA) in shotcrete mixtures enhanced the long-term performance but invited massive white efflorescence on surface layer under partial-immersion exposure condition. Silica fume (SF) admixture can compensate the undesired reduction of early-age strength caused by FA addition, but make these specimens more susceptible to sulfate attack. Mercury intrusion porosimetry (MIP) analysis, scanning electron microscopy (SEM), and X-ray diffraction (XRD) tests reveal that these consequences were strongly related to the refinement of microstructure resulted from pozzolanic reactions and hydration kinetics.

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