scholarly journals Fresh/Mechanical/Durability Properties and Structural Performance of Enginnered Cementitious Composite (ECC)

2021 ◽  
Author(s):  
Maulin Bipinchandra Mavani

Engineered Cementitious Composite (ECC) is an ultra ductile concrete with strain-hardening and multiple-cracking behaviour in tension and flexure. Fresh, mechanical and durability properties of different ECC mixtures are evaluated by incorporating supplementary cementitious materials (class F, CI fly ash and slag) and different aggregate type. Experimental studies demonstrated viability of producing greener, sustainable and cost-effective ECC using locally available aggregates (crushed sand) instead of microsilica sand and fly ash (Class CI or F) of up to 70% cement replacement having similar or better fresh, mechanical and durability properties. Structural validation by small scale tests on bridge decks with ECC link slab and by push out tests to evaluate stud shear connector-ECC interaction compared with self-consolidating concrete (SCC) proved feasibility and advantages of these ECC mixes. Based on research, recommendations are made for ECC mix design and their application in link slab construction in bridge structures.

2021 ◽  
Author(s):  
Maulin Bipinchandra Mavani

Engineered Cementitious Composite (ECC) is an ultra ductile concrete with strain-hardening and multiple-cracking behaviour in tension and flexure. Fresh, mechanical and durability properties of different ECC mixtures are evaluated by incorporating supplementary cementitious materials (class F, CI fly ash and slag) and different aggregate type. Experimental studies demonstrated viability of producing greener, sustainable and cost-effective ECC using locally available aggregates (crushed sand) instead of microsilica sand and fly ash (Class CI or F) of up to 70% cement replacement having similar or better fresh, mechanical and durability properties. Structural validation by small scale tests on bridge decks with ECC link slab and by push out tests to evaluate stud shear connector-ECC interaction compared with self-consolidating concrete (SCC) proved feasibility and advantages of these ECC mixes. Based on research, recommendations are made for ECC mix design and their application in link slab construction in bridge structures.


10.29007/81v5 ◽  
2018 ◽  
Author(s):  
Ashika Shah ◽  
Indrajit Patel ◽  
Jagruti Shah ◽  
Gaurav Gohil

In the production of Self Compacting concrete (SCC), the use of quaternary blend of supplementary cementitious materials (SCM’s) has not found enough applications. For this purpose, an effort has been done to present a mix design for M60 grade and M80 grade SCC with quaternary blending of fly ash(FA), ground granulated blast furnace slag (GGBS), silica fume (SF) in accordance with EFNARC guidelines. Findings: In this study, cement has been replaced with SCM’s from 30% to 50%. Fresh properties of concrete were tested for slump flow, T50 test and U box. The hardened properties of concrete were tested for compressive strength and durability. The tests were performed for 7, 28, 56 and 91 days. The results indicate that the use of quaternary blend has improved the workability, compressive strength and durability properties of specimens than the control specimen. Application: The primary contribution is to fill the congestedreinforcement and increase the durability and life span of the structure.


2020 ◽  
Vol 71 (7) ◽  
pp. 775-788
Author(s):  
Quyet Truong Van ◽  
Sang Nguyen Thanh

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


Materials ◽  
2021 ◽  
Vol 14 (3) ◽  
pp. 475
Author(s):  
Ana María Moreno de los Reyes ◽  
José Antonio Suárez-Navarro ◽  
Maria del Mar Alonso ◽  
Catalina Gascó ◽  
Isabel Sobrados ◽  
...  

Supplementary cementitious materials (SCMs) in industrial waste and by-products are routinely used to mitigate the adverse environmental effects of, and lower the energy consumption associated with, ordinary Portland cement (OPC) manufacture. Many such SCMs, such as type F coal fly ash (FA), are naturally occurring radioactive materials (NORMs). 226Ra, 232Th and 40K radionuclide activity concentration, information needed to determine what is known as the gamma-ray activity concentration index (ACI), is normally collected from ground cement samples. The present study aims to validate a new method for calculating the ACI from measurements made on unground 5 cm cubic specimens. Mechanical, mineralogical and radiological characterisation of 28-day OPC + FA pastes (bearing up to 30 wt % FA) were characterised to determine their mechanical, mineralogical and radiological properties. The activity concentrations found for 226Ra, 212Pb, 232Th and 40K in hardened, intact 5 cm cubic specimens were also statistically equal to the theoretically calculated values and to the same materials when ground to a powder. These findings consequently validated the new method. The possibility of determining the activity concentrations needed to establish the ACI for cement-based materials on unground samples introduces a new field of radiological research on actual cement, mortar and concrete materials.


2019 ◽  
Vol 4 ◽  
pp. 9-15
Author(s):  
Md Shamsuddoha ◽  
Götz Hüsken ◽  
Wolfram Schmidt ◽  
Hans-Carsten Kühne ◽  
Matthias Baeßler

Grouts have numerous applications in construction industry such as joint sealing, structural repair, and connections in precast elements. They are particularly favoured in rehabilitation of structures due to penetrability and convenience of application. Grouts for repair applications typically require high-performance properties such as rapid strength development and superior shrinkage characteristics. Sometimes industrial by-products referred as supplementary cementitious materials (SCM) are used with neat cement due to their capabilities to provide binding properties at delayed stage. Micro silica, fly ash and metakaolin are such SCMs, those can modify and improve properties of cement products. This study aims at investigating long-term mass loss and linear shrinkage along with long-term compressive and flexural strength for grouts produced from ultrafine cement and SCMs. A series of mixtures were formulated to observe the effect of SCMs on these grout properties. Properties were determined after 365 days of curing at 23oC and 55% relative humidity. The effect of SCMs on the properties are characterised by statistical models. Response surfaces were constructed to quantify these properties in relation to SCMs replacement. The results suggested that shrinkage was reduced by metakaolin, while micro silica and fly ash had positive effects on compressive and flexural strength, respectively.


2016 ◽  
Vol 711 ◽  
pp. 21-28
Author(s):  
Francisco J. Presuel-Moreno

The performance with regard to chloride penetration of specimens made with three base compositions (supplementary cementitious materials: 20% fly ash, 20% fly ash + 8% silica fume, and 50% slag replacement by weight of cement), and water-to-cementitious ratios of 0.35, 0.41, or 0.47 were investigated here. In this investigation, laboratory experiments were carried out to study the correlation between electrical resistivity and non-steady state chloride ion migration coefficients (Dnssm) of concrete. NT Build 492 was used to determine chloride migration coefficients. Rapid migration tests and resistivity measurements were performed several times over two years, and the non-steady state migration coefficient (Dnssm) vs. resistivity values were correlated. Experimental results show that a good correlation was found between electrical resistivity and Dnssm. Based on the relationships developed from this investigation, it appears that the correlations are age and composition dependent.


2019 ◽  
Vol 292 ◽  
pp. 102-107 ◽  
Author(s):  
Josef Fládr ◽  
Petr Bílý ◽  
Karel Šeps ◽  
Roman Chylík ◽  
Vladimír Hrbek

High-performance concrete is a very specific type of concrete. Its production is sensitive to both the quality of compounds used and the order of addition of particular compounds during the homogenization process. The mechanical properties were observed for four dosing procedures of each of the three tested concrete mixtures. The four dosing procedures were identical for the three mixes. The three mixes varied only in the type of supplementary cementitious material used and in water content. The water content difference was caused by variable k-value of particular additives. The water-to-binder ratio was kept constant for all the concretes. The additives used were metakaolin, fly ash and microsilica. The comparison of particular dosing procedures was carried out on the values of basic mechanical properties of concrete. The paper compares compressive strength and depth of penetration of water under pressure. Besides the comparsion of macro-mechanical properties, the effect of microsilica and fly ash additives on micro-mechanical properties was observed with the use of scanning electron microscopy (SEM) and nanoindentation data analysis. Nanoindentation was used to determine the thickness and strength of interfacial transition zone (ITZ) for different sequence of addition of cement, additive and aggregate. The thickness obtained by nanoindentation was further investigated by SEM EDS line scanning.


Author(s):  
W. Micah Hale ◽  
Thomas D. Bush ◽  
Bruce W. Russell ◽  
Seamus F. Freyne

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.


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