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

2019 ◽  
Vol 5 (1) ◽  
pp. 18 ◽  
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.

Effect of Curing Temperature on Hardened Concrete Properties

2005 ◽  
Vol 1914 (1) ◽  
pp. 97-104 ◽  
Author(s):  
W. Micah Hale ◽  
Thomas D. Bush ◽  
Bruce W. Russell ◽  
Seamus F. Freyne
Keyword(s):  
Fly Ash ◽  
Cementitious Materials ◽  
Curing Temperature ◽  
Supplementary Cementitious Materials ◽  
Cold Weather ◽  
Strength Development ◽  
Hardened Concrete ◽  
Hardened Properties ◽  
Hot Weather ◽  
Materials Used

Often, concrete is not mixed or placed under ideal conditions. Particularly in the winter or the summer months, the temperature of fresh concrete is quite different from that of concrete mixed under laboratory conditions. This paper examines the influence of supplementary cementitious materials on the strength development (and other hardened properties) of concrete subjected to different curing regimens. The supplementary cementitious materials used in the research program were ground granulated blast furnace slag (GGBFS), fly ash, and a combination of both materials. The three curing regimens used were hot weather curing, standard curing, and cold weather curing. Under the conditions tested, the results show that the addition of GGBFS at a relatively low replacement rate can improve the hardened properties for each curing regimen. This improvement was noticeable not only at later ages but also at early ages. Mixtures that contained both materials (GGBFS and fly ash) performed as well as and, in most cases, better than mixtures that contained only portland cement in all curing regimens.

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 The Relationship between Cementitious Composition and Properties of Ultrahigh Strength Concrete

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.

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

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.

scholarly journals The impact of metakaolin, silica fume and fly ash on the temperature resistance of high strength cement paste

2021 ◽  
Author(s):  
Nabil Abdelmelek ◽  
Eva Lubloy
Keyword(s):  
Fly Ash ◽  
Silica Fume ◽  
Cement Paste ◽  
Elevated Temperatures ◽  
High Strength ◽  
Cementitious Materials ◽  
Supplementary Cementitious Materials ◽  
Temperature Resistance ◽  
Maximum Temperatures ◽  
The Impact

AbstractThe effects of elevated temperatures on the properties of high-strength cement paste (HSCP) based on metakaolin (MK), silica fume (SF), and fly ash (FA) were studied in the current experimental research. The resistance of HSCP against elevated temperatures was evaluated as well. The new method is expressed by the total area under each curve of strength, known as “temperature resistance”, is adopted. Results of the HSCP mixtures containing MK, SF, and FA with replacements ratios of 9%, 6% and 15% have shown excellent temperature resistance at all levels of maximum temperatures, respectively. Properties added to HSCP by these supplementary cementitious materials (SCM) such as decreasing the amount of CaO and increasing the amounts of SiO2 and Al2O3 have minimized the harmful effects of the use of pure ordinary Portland cement (OPC) at elevated temperatures. The results have shown also that the grinding fineness of OPC influences the amount of optimum replacement of the used SCM on HSCP at elevated temperatures. Hence, the amount of optimum replacement of MK blended with CEM I 42.5 N was 9% whereas, the amount of optimum replacement of MK blended with CEM I 52.5 N shifted to 3%. Finally, the fineness of cement of 4500 cm2 g−1 has shown a better-elevated temperature resistance compared to the cement with a fineness of 4000 cm2 g−1 in case of using pure OPC.

scholarly journals Experimental study on Strength Attainment of concrete containing silica fume and fly ash

2021 ◽  
Vol 1197 (1) ◽  
pp. 012003
Author(s):  
G.V.V. Raj Kishore
Keyword(s):  
Fly Ash ◽  
Silica Fume ◽  
High Strength Concrete ◽  
High Strength ◽  
Cementitious Materials ◽  
Supplementary Cementitious Materials ◽  
Strength Concrete ◽  
Construction Techniques ◽  
Class F Fly Ash ◽  
Strength And Durability

Abstract Increased utilization of cement in recent construction techniques leads to the global gas emission and involves high cost. Many researchers investigated the incorporation of pozzolanic materials in the cement in order to reduce its notorious effects on the environment which directed this research in order to develop high strength concrete by partially replacing supplementary cementitious materials with the cement. This study represents the experimental investigation on concrete which is blended with class F fly ash and silica fume in order to obtain high strength concrete. For this purpose, silica fume is used in 6%, 9% fly ash is replaced with 30%,40% and 50% by weight of cement. The specimens were subjected to curing up to 90 days and conducted tests in order to determine the mechanical properties like compressive strength, flexural strength and durability properties like RCPT and UPV. Based on the experimental results, addition of 6% silica fume and fly ash at 30% replacement is high strength attainment as well as durability in the concrete.

scholarly journals Effect on blending of supplementary cementitious materials on performance of normal strength concrete

2019 ◽  
Vol 10 (3) ◽  
pp. 253-258
Author(s):  
S. Jagan
Keyword(s):  
Fly Ash ◽  
Silica Fume ◽  
Steel Slag ◽  
Cementitious Materials ◽  
Supplementary Cementitious Materials ◽  
Partial Replacement ◽  
Optimum Level ◽  
Fine Aggregate ◽  
River Sand ◽  
Split Tensile Strength

Sustainability and scarcity in resources are the two major issues to be dealt within the present scenario by effective utilization of alternative materials. In this present study, an attempt has been taken to study the effect of supplementary materials such as fly ash and silica fume as a partial replacement to cement and steel slag and M-sand as a replacement to river sand on strength and durability of concrete. In this study, concrete specimens were prepared based on five different mixes by varying the percentages of these supplementary materials. Various mechanical properties like compressive strength, split tensile strength and flexural strength were performed to ascertain the mix with optimum levels of replacement of supplementary materials for cement and fine aggregate. Durability property like water absorption test was performed on the mix with optimum values of strength. Results revealed that mix with higher percentages of steel slag, optimum level of silica fume and fly ash have shown higher strength and lesser permeability in concrete.

Engineered Properties of Sustainable Cement-Based Composites Containing Recycled Rock Wool and Supplementary Cementitious Materials

2013 ◽  
Vol 284-287 ◽  
pp. 113-117 ◽  
Author(s):  
Wei Ting Lin ◽  
Ta Yuan Han ◽  
Yuan Chieh Wu ◽  
An Cheng ◽  
Ran Huang ◽  
...  
Keyword(s):  
Fly Ash ◽  
Cementitious Materials ◽  
Mineral Admixture ◽  
Supplementary Cementitious Materials ◽  
Test Results ◽  
Replacement Ratio ◽  
Supplementary Cementitious Material ◽  
The Difference ◽  
High Level ◽  
Rock Wool

This study investigates the properties of cement-based composites with addition of various recycled rock wools and compare with the properties of composites containing fly ash and ggbs. The use of recycled rock wool is with a cylindrical and fiber-shape particle less than 75 μm. Based on the chemical composition and particle size distribution, the material properties of recycled rock wool are similar to other pozzolanic materials such as fly ash and ggbs and can be use a supplementary cementitious material. The experimental results show that partially replacing cement with recycled rock wool improves the compressive strength and porestructure, but reduce the flow spread at the high level replacement. Therefore, the test results indicate that recycled rock wool is an effective mineral admixture, with 10 % to 30 % as suitable replacement ratio of cement for the difference water/cementitious ratios.

Compressive Strength and Chloride Ion Permeability Test of Concrete Incorporating Fly Ash and GGBS with Diverse Water Binder Ratio

2022 ◽  
Vol 1048 ◽  
pp. 311-320
Author(s):  
Tarun Gehlot ◽  
Suresh Singh Sankhla ◽  
Sangeeta Parihar
Keyword(s):  
Fly Ash ◽  
Compression Test ◽  
Chloride Ion ◽  
Cementitious Materials ◽  
Mineral Admixture ◽  
Supplementary Cementitious Materials ◽  
Permeability Test ◽  
Ion Permeability ◽  
Binder Ratio ◽  
Water Binder Ratio

In this study conventional concrete of M40 grade developed with diverse water binder ratio and fixed optimum dosage of 30% mineral admixture fly ash and GGBS with weight of cement .Compression test has been conducted on cube samples and Rapid Chloride permeability test (RCPT) are conducted on cylindrical specimens to acknowledge durability parameter. Compression test results has been enhanced with replacement of supplementary cementitious materials and chloride ion permeability has been reduced with substitution of fly ash and GGBS .incremental of water binder ratio also reduce the permeability value however compression value increased

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