The Effectiveness of Pumice as a Supplementary Cementitious Material Within High Performance Self-Consolidating Concrete

The Effectiveness of Pumice as a Supplementary Cementitious Material Within High Performance Self-Consolidating Concrete
Author: Mitchel Anthony
Publisher:
Total Pages: 0
Release: 2022
Genre:
ISBN:

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Self-Consolidating Concrete (SCC) is a highly flowable form of concrete that can fill formwork without mechanical consolidation or segregation. Self-Consolidating Concrete has gained popularity in recent times due its high workability. The high workability of Self-Consolidating Concrete is primarily achieved with the inclusion of a High-Range Water Reducing Admixture (HRWRA) within the material matrix. The inclusion of an HRWRA provides high workability, yet avoids material segregation. Self-Consolidating Concrete workability is measured by the ASTM C1621 J-Ring flow test which measures the spread diameter of the fresh concrete from an inverted mold. Project requirements may also require Self-Consolidating Concrete to achieve high strength. The inclusion of an HRWRA allows the concrete mix to have a lesser water-to-cement ratio, thus increasing the compressive strength of the mix. An additional method to achieve high strength is to incorporate a supplementary cementitious material within the material matrix, with Metakaolin being one of the more common supplementary cementitious materials. A potential supplementary cementitious alternative to Metakaolin is Pumice. The primary focus of the experimental research is to evaluate the effectiveness of pumice as a supplementary cementitious material within high performance Self-Consolidating Concrete. Two grades of supplementary cementitious Pumice (Hess NCS-3 and Hess NDS325) were evaluated during the experimental testing, which were compared against Metakaolin and conventional Self-Consolidating Concrete. The experimental research was conducted in three phases with a primary focus on workability, 7-day, and 28-day compressive strength testing. Secondary testing (air content and tensile testing) was conducted during Phase II to acquire additional attributes of each Self-Consolidating Concrete mix. Phase I testing was performed on Pumice, Metakaolin, and conventional Self-Consolidating mortar cubes to develop preliminary mix designs for each alternative. The primary target for Phase I testing was to develop the appropriate cement quantity to be replaced by the supplementary cementitious material. Testing was conducted on 0%, 5%, 10%, and 15% replacement alternatives within each mix design. Phase II testing was then conducted using Self-Consolidating Concrete cylinders and used the preliminary Phase I mix designs as a reference. The primary focus of Phase II testing was to refine the preliminary mix designs and evaluate each Pumice grade's effectiveness as a supplementary cementitious material. Only the better performing Pumice grade was incorporated into Phase III testing. The intent of Phase III testing was to refine the Phase II mix designs, and make final a recommendation on the effectiveness of Pumice as supplementary cementitious material while using the refined Metakaolin mix designs as a datum. Phase I testing determined that 15% cement replacement was most effective for Metakaolin, NCS-3 Pumice, and NDS325 Pumice. The mortar mix design with 15% Metakaolin replacement provided an average 28-day compressive strength of 10,156 psi, whereas NCS-3 and NDS325 Pumice provided a strength of 6,491 psi, and 5,575 psi respectively. Phase II testing concluded that NCS-3 was the better performing supplementary cementitious Pumice grade with an average 28-day Self-Consolidating Concrete cylinder compressive strength of 9,779 psi compared to NDS325's 7,813 psi compressive strength. Phase III testing concluded that Self-Consolidating Concrete mixes using Metakaolin as a supplementary cementitious material provided the highest 28-day average compressive strength at 11,206 psi. NCS-3 Pumice was competitive with the highest 28-day average compressive strength of 11,067 psi. Metakaolin, however, well outperformed NCS-3 Pumice during 7-day compressive strength testing with average highs of 10,836 psi, and 8,812 psi respectively. Workability testing completed during Phase II and III revealed that Self-Consolidating Concrete incorporating Pumice outperformed Metakaolin mixes. Based upon the above findings, it was concluded that NCS-3 Pumice can be used as an effective alternative supplementary cementitious material to Metakaolin for use in high performance Self-Consolidating Concrete.

Development and Characterization of Sustainable Self-Consolidating Concrete Containing High Volume of Limestone Powder and Natural Or Calcined Pozzolanic Materials

Development and Characterization of Sustainable Self-Consolidating Concrete Containing High Volume of Limestone Powder and Natural Or Calcined Pozzolanic Materials
Author: Kemal Celik
Publisher:
Total Pages: 138
Release: 2015
Genre:
ISBN:

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Carbon dioxide emission from ordinary Portland cement manufacturing is one of the major sustainability issues facing the concrete industry. In fact, the annual worldwide CO2 emission from cement manufacturing is nearly 7% of the global emissions. Roughly 60% of these emissions come from the calcination of limestone, the main raw material for making Portland-cement clinker. The remaining CO2 emission is as a result of fuel combustion required to generate the heat necessary for the reactions forming clinker. Although considerable gains in energy efficiency have been achieved during the production of cement for the last two decades, calcination of limestone is the major concern as a source of CO2 emissions. Utilization of high-volume of by-products or natural pozzolanic material, such as basaltic ash pozzolan or fly ash as a replacement of Portland cement clinker, is a possible approach to reduce the clinker factor of Portland cement. In addition, self-consolidating concrete mixtures are being increasingly used for the construction of highly reinforced complex concrete elements and for massive concrete structures such as thick foundation due to its technical advantages such as shortened placement time, labor savings, improved compaction, and better encapsulation of rebar. Self-consolidating concrete requires utilization of high dosage of a plasticizing agent or viscosity-modifying chemical admixtures. The purpose of this study is to develop highly flowable self-consolidating concrete mixtures made of high proportions of cement replacement materials such as basaltic ash pozzolan, fly ash and pulverized limestone instead of high dosage of a plasticizer or viscosity-modifying admixtures, and characterize the effects of Portland cement replacement on the strength and durability. The two replacement materials used are high-volume finely-ground basaltic ash, a Saudi Arabian aluminum-silica rich basaltic glass and high-volume Class-F fly ash, from Jim Bridger Power Plant, Wyoming US. As an extension of the study, limestone powder was also used to replace Portland cement, alongside finely-ground basaltic ash and Class-F fly ash, forming ternary blends. Along with compressive strength tests, non-steady state chloride migration, water absorption and gas permeability tests were performed, as durability indicators, on self-consolidating concrete (SCC) specimens. The results were compared to two reference concretes; 100% ordinary Portland cement and 85% ordinary Portland cement - 15% limestone powder by weight. The high-volume of basaltic pozzolan and fly ash concrete mixtures showed strength and durability results comparable to those of the reference concretes at later ages; identifying that both can effectively be used to produce low-cost and environment-friendly self-consolidating concrete without utilizing viscosity-modifying admixture. Even though the slump flow diameter of SCC specimens was held in the similar range by utilizing varied amount of water reducer admixture, they were not identical. To enable a precise comparison among the specimens, the mortar specimens were produced that had same cement-replacement ratios with the ones in SCC specimens utilizing basaltic ash pozzolan (NP), Class-F fly ash (FA) and limestone powder without using water reducer admixture. Overall the binary and ternary FA samples had higher strength than NP mortar samples up to 1 year. This can be attributed to the higher pozzolanic reactivity of FA compared to NP which is supported by X-ray diffraction, isothermal calorimetry and thermogravimetric analysis. The normal consistency and setting time of the mixtures were determined. It showed that cement replacement with limestone powder in the ternary blended cements containing either basaltic ash pozzolan or Class-F fly ash along with ordinary Portland cement lowered the initial and final time of setting relative to the binary blended cements containing similar ratio of cement replacement. Also, the water demand of mixtures incorporate with basaltic ash pozzolan was greater than the one with Class-F fly ash. The influence of the basaltic ash pozzolan, Class-F fly ash and limestone powder in the binary and ternary Portland cement blends is discussed, while following the physicochemical changes such as crystalline transition, hydration kinetics, and mechanical property that are a direct result of the addition of supplementary cementitious material or filler. Selected cement pastes were characterized by X-ray diffraction (XRD), petrographic microscopy and scanning electron microscopy with energy dispersive spectroscopy, isothermal calorimetry and thermogravimetric analysis (TGA). Integrating these techniques helps to understand the fresh and hardened properties of concretes and brings new insight into the effect of basaltic ash pozzolan, Class-F fly ash and limestone powder on the hydration of Portland cement. Isothermal calorimetry analysis presents that the addition of limestone powder, for instance, increased the rate of hydration reaction relative to the control specimen. This suggests that as a result of the further participation of aluminate phases in hydration reaction, the hydration products were improved. This outcome was confirmed with the analysis of XRD results by the finding carboaluminates in the limestone powder containing blended cements. It is important to note that the enhancement of hydration reaction was not adequate to compensate for the dilution effect due to addition of limestone powder. While the replacement of ordinary Portland cement with Class-F fly ash retarded the rate of hydration reaction relative to the one with basaltic ash pozzolan at first, the reactivity of Class-F fly ash improved after 2 days of hydration and surpassed the cumulative heat of hydration of basaltic ash pozzolan. This result is supported by TGA analysis demonstrating that the mixtures containing Class-F fly ash had more hydrate water with respect to the one of with basaltic ash pozzolan. XRD analysis showed that the addition of limestone powder in the ternary cement containing either basaltic ash pozzolan or fly ash led to stabilize the transformation of ettringite to monosulfate and introduce the carboaluminates in the hydration products. TGA analysis indicated that the degree of pozzolanic reaction of fly ash was higher than the one with basaltic ash in the binary and ternary blended mixtures. For a comprehensive analysis and quantification of emissions and global warming potential (GWP) from concrete production, life-cycle assessment was used on the concrete mixture containing Class-F fly ash. It is found that high volume, up to 55% by weight replacement of ordinary Portland cement with Class-F fly ash, or Class-F fly ash and limestone powder produces highly workable concrete that has high 28-day and 365-day strength, and extremely high to very high resistance to chloride penetration along with low GWP for concrete production.

Supplementary Cementing Materials

Supplementary Cementing Materials
Author: Rafat Siddique
Publisher: Springer Science & Business Media
Total Pages: 297
Release: 2011-03-28
Genre: Technology & Engineering
ISBN: 3642178669

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This book is an attempt to consolidate the published research related to the use of Supplementary Cementing Materials in cement and concrete. It comprises of five chapters. Each chapter is devoted to a particular supplementing cementing material. It is based on the literature/research findings published in journals/conference proceeding, etc. Topics covered in the book are; coal fly ash, silica fume (SF), granulated blast furnace slag (GGBS), metakaolin (MK), and rice husk ash (RHA). Each chapter contains introduction, properties of the waste material/by-product, its potential usage, and its effect on the properties of fresh and hardened concrete and other cement based materials.

Potential of Portland-Limestone Cement to Improve Performance of Concrete Made With High Slag Cement and Fly Ash Replacement Rates

Potential of Portland-Limestone Cement to Improve Performance of Concrete Made With High Slag Cement and Fly Ash Replacement Rates
Author: J. Shannon
Publisher:
Total Pages: 17
Release: 2016
Genre: Fly ash
ISBN:

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Aggressive use of supplementary cementitious materials (SCMs) in concrete is becoming more appealing due to potential for cost effectiveness, reduced environmental impact, enhanced durability, and increased sustainability. Constructability, though, is often less attractive as time of set and early strength development can be delayed. This paper investigated the merits of incorporating portland-limestone cement (PLC) to improve concrete sustainability and performance when rounded gravel aggregates (most sustainable for some markets) were used in conjunction with dual SCMs proportioned for 50 % to 70 % total cement replacement. The family of concrete mixtures evaluated have not been widely studied with PLC (in the US or elsewhere). Mixtures containing PLC designed for improved synergies in the US construction market were compared to similar variations containing ordinary portland cement (OPC). PLC was shown to be able to produce concrete mixtures of greater compressive strength and lower set times compared to OPC in some, but not all, conditions. Individual mixture performance varied based on SCM use, PLC properties, and aggregate properties.

Evaluating Natural Pozzolans for Use as Alternative Supplementary Cementitious Materials in Concrete

Evaluating Natural Pozzolans for Use as Alternative Supplementary Cementitious Materials in Concrete
Author: Saamiya Seraj
Publisher:
Total Pages: 316
Release: 2015
Genre:
ISBN:

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Concerns over the future availability of traditional SCM sources, such as fly ash, have left the concrete industry in need of alternative sources of SCMs. The research presented here has evaluated natural pozzolans such as pumice, perlite, vitric ash, zeolites, shale and calcined clay as alternative sources of SCMs. Unlike previous research that has only concentrated on empirically evaluating the performance of natural pozzolans in concrete, the research presented in this dissertation has measured both the performance of the pozzolans in cementitious mixtures as well as their physical and chemical characteristics, to draw meaningful relationships between pozzolan properties and performance. The physical and chemical characteristics of these natural SCMs were measured using techniques like particle size analysis, Brunauer-Emmett-Teller (BET) surface area, scanning electron microscope (SEM) imaging, x-ray fluorescence (XRF), x-ray diffraction (XRD), and thermal gravimetric analysis (TGA). The performance of the pozzolans as alternative SCMs was examined by looking at their effect on mortar strength and mixture workability, as well as by their ability to mitigate expansions from durability problems like alkali silica reaction (ASR) and sulfate attack. The performance of the pozzolans was related back to their physical and chemical characteristics to gain an understanding of the underlying mechanisms of cement and pozzolan interaction, and to draw insights as to why some pozzolans perform better than others in cementitious mixtures. Using this knowledge, some of the under-performing pozzolans were modified to see if changes in their properties could improve performance. Results of the research showed that other than the two coarse zeolites, the rest of the pozzolans tested could be used as Class F fly ash replacements in concrete, with the pumice, perlite, metakaolin and fine zeolite being the best performers in terms of mortar strength and durability. Although the pumice mortar had lower strengths than the control at early ages, results from the performance improvement studies showed that the reactivity of pumice could be enhanced by grinding the pozzolans to a finer particle size distribution. Zeolites were found to negatively affect mixture workability, but calcination of the zeolites helped to improve the workability of zeolite mixtures.

High-Volume Mineral Admixtures in Cementitious Binders

High-Volume Mineral Admixtures in Cementitious Binders
Author: Dan Tsang
Publisher: Elsevier
Total Pages: 536
Release: 2024-09-07
Genre: Technology & Engineering
ISBN: 0443134995

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High-Volume Mineral Admixtures in Cementitious Binders: Towards Carbon-Neutral Construction delivers an overview of the broad applications of high-volume supplementary cementitious materials (SCMs) in cementitious binders, addressing the most promising ways to use them to reduce carbon emissions in the construction and building industry. This book focuses on the applications and scientific challenges of high-volume SCMs blends, elaborating on the possibilities as well as offering original perspectives on using different kinds of blended cements in the manufacturing process. Emphasis is placed on activity estimation and quality assessment, the properties of high-volume SCM-blends at both the fresh and hardened stages, self-hydraulic properties, and potential use as the sole binder, as well as associated environmental impacts and carbon footprint reduction. Presents the macro-/microproperties of high-volume (SCMs) cements. Introduces the state of the art in the use of high-volume SCM cements. Discusses the associated environmental impacts and the contribution to carbon neutrality by using high-volume SCMs. Associated with the disposal of man-made waste in the production of building materials. Discusses the advantages of using waste materials in cement production which reduce environmental impacts and contribute to sustainable development.

Ultra-High Performance Concrete

Ultra-High Performance Concrete
Author: Caijun Shi
Publisher: CRC Press
Total Pages: 505
Release: 2024-02-23
Genre: Technology & Engineering
ISBN: 100383471X

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Ultra-high performance concrete (UHPC) is an advanced cement-based composite material with compressive strength of over 120 MPa, high toughness, and superior durability. Since its development in the early 1990s, UHPC has attracted great interest worldwide due to its advantages. This book covers material selection and mixture design methods for developing UHPC, as well as the performance of UHPC, including fresh and hardened properties, setting and hardening, dimensional stability, static and dynamic properties, durability, long-term properties, and self-healing properties. A range of potential applications and case studies are presented to illustrate how UHPC meets requirements for lightweight, high-rise, large-span, heavy-load bearing, fast-construction, and highly durable structures in civil and construction engineering. Also introduced is a typical new concrete, seawater sea-sand UHPC, which avoids the use of freshwater and river sand in marine construction. The first book to fully cover the design, performance, and applications of UHPC, this is ideal for concrete technologists, designers, contractors, and researchers.

Geoheritage of Volcanic Harrats in Saudi Arabia

Geoheritage of Volcanic Harrats in Saudi Arabia
Author: Mohammed Rashad Moufti
Publisher: Springer
Total Pages: 205
Release: 2016-06-24
Genre: Science
ISBN: 3319330152

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This book records the geoheritage values of globally significant, yet little-known, volcanic geosites in Saudi Arabia. It is the first of its kind to focus on the Middle East, clearly showing the hidden geoheritage value of the volcanic Arabian Peninsula’s harrats and demonstrating why the Saudi Arabian volcanic fields are unique. Along with the systematic geosite description, the book introduces scientifically founded geoeducational programs that can be used to develop our understanding of volcanic geoheritage values of volcanic fields. It offers a detailed and comprehensive research-based description of four of the most accessible volcanic harratts in Saudi Arabia and an additional summary of other more remote fields. Additionally, it discusses geoeducational programs that could be used to link these volcanic areas and use them in volcanic hazard education.

Design and Control of Concrete Mixtures

Design and Control of Concrete Mixtures
Author: Steven H. Kosmatka
Publisher:
Total Pages: 224
Release: 1988
Genre: Technology & Engineering
ISBN:

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Portland Cement Association reference, dealing with fundamentals, cold weather concreting, curing, admixtures, aggregates, mixing, and much more.