Long-term mechanical and shrinkage properties of cementitious grouts for structural repair

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.

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Effect of Curing Temperature on Hardened Concrete Properties

Transportation Research Record Journal of the Transportation Research Board ◽

10.1177/0361198105191400112 ◽

2005 ◽

Vol 1914 (1) ◽

pp. 97-104 ◽

Cited By ~ 1

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.

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Effect of MIRHA and Fly Ash in Ductile Self-Compacting Concrete on Abrasion and Impact Performance

Applied Mechanics and Materials ◽

10.4028/www.scientific.net/amm.567.393 ◽

2014 ◽

Vol 567 ◽

pp. 393-398 ◽

Cited By ~ 1

Author(s):

Muhd Fadhil Nuruddin ◽

Norzaireen Mohd Azmee ◽

Kok Yung Chang

Keyword(s):

Fly Ash ◽

Impact Resistance ◽

Cementitious Materials ◽

Supplementary Cementitious Materials ◽

Impact Performance ◽

Cement Replacement ◽

Positive Effects ◽

Partial Cement Replacement ◽

Reference Specimens ◽

The Cost

The benefits of Microwave Incinerated Rice Husk Ash (MIRHA) as partial cement replacement materials in DSCC mixes has led to the research on the possibilities of combining both MIRHA and fly ash as an addition in DSCC replacing up to 20% of cement volume whilst maintaining satisfactory properties. The addition of both materials can improve concrete properties and reduce the cost of DSCC production. These supplementary cementitious materials are expected to give positive effects on the concrete abrasion and impact resistance. The incorporations of both MIRHA and fly ash in DSCC as cement replacement materials are considered as a new type of concrete. Therefore, it is important to have a complete knowledge on the behaviour of the composite material when being subjected to repetitive dynamic loading. The test results showed that MIRHA and fly ash combination in DSCC improved both abrasion and impact resistance of DSCC compared to reference specimens.

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Detoxified Spent Pot Lining from Aluminum Production as (Alumino-)Silicate Source for Composite Cement and AutoClaved Aerated Concrete

Applied Sciences ◽

10.3390/app11083715 ◽

2021 ◽

Vol 11 (8) ◽

pp. 3715

Author(s):

Arne Peys ◽

Mateja Košir ◽

Ruben Snellings ◽

Ana Mladenovič ◽

Liesbeth Horckmans

Keyword(s):

Fly Ash ◽

Chemical Reactivity ◽

Coal Fly Ash ◽

Cementitious Materials ◽

Supplementary Cementitious Materials ◽

Aluminum Production ◽

Strength Development ◽

Autoclaved Aerated Concrete ◽

Concrete Blocks ◽

Aerated Concrete

New sources of supplementary cementitious materials (SCMs) are needed to meet the future demand. A potential new source of SCM is spent pot lining, a residue from aluminum production. The present work showed that the refined aluminosilicate part of spent pot lining (SPL) has a moderate chemical reactivity in a cementitious system measured in the R3 calorimetry test, comparable to commercially used coal fly ash. The reaction of SPL led to the consumption of Ca(OH)2 in a cement paste beyond 7 days after mixing. At 28 and 90 days a significant contribution to strength development was therefore observed, reaching a relative strength, which is similar to composite cements with coal fly ash. At early age a retardation of the cement hydration is caused by the SPL, which should most likely be associated with the presence of trace amounts of NH3. The spent pot lining is also investigated as silica source for autoclaved aerated concrete blocks. The replacement of quartz by spent pot lining did not show an adverse effect on the strength-density relation of the lightweight blocks up to 50 wt% quartz substitution. Overall, spent pot lining can be used in small replacement volumes (30 wt%) as SCM or as replacement of quartz (50 wt%) in autoclaved aerated concrete blocks.

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Effect of High Calcium Fly Ash, Ladle Furnace Slag, and Limestone Filler on Packing Density, Consistency, and Strength of Cement Pastes

Materials ◽

10.3390/ma14020301 ◽

2021 ◽

Vol 14 (2) ◽

pp. 301

Author(s):

Eleftherios K. Anastasiou

Keyword(s):

Fly Ash ◽

Cementitious Materials ◽

Supplementary Cementitious Materials ◽

Strength Development ◽

Ladle Furnace ◽

Limestone Filler ◽

Cement Pastes ◽

High Calcium ◽

High Calcium Fly Ash ◽

Furnace Slag

Environmental considerations and technical benefits have directed research towards reducing cement clinker content in concrete, and one of the best ways to do this is to replace cement with supplementary cementitious materials. High calcium fly ash, ladle furnace slag, and limestone filler were investigated as supplementary cementitious materials in cement pastes, and binary mixtures were produced at 10%, 20%, and 30% cement replacement rates for each material. The water requirement for maximum packing and for normal consistency were obtained for each paste, and strength development was determined at 3, 7, 28, and 90 days for the 20% replacement rate. Furthermore, two ternary mixtures at 30% cement replacement were also prepared for maximum packing density and tested for compressive strength development. The results showed that high calcium fly ash decreased cement paste packing and increased water demand but contributed to strength development through reactivity. Ladle furnace slag and limestone filler, on the other hand, were less reactive and seemed to contribute to strength development through the filler effect. The ternary paste with 70% cement, 20% high calcium fly ash, and 10% limestone filler showed equivalent strength development to that of the reference cement paste.

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Assessment of Rational Design of Self-Compacting Concrete Incorporating Fly Ash and Limestone Powder in Terms of Long-Term Durability

Materials ◽

10.3390/ma13122863 ◽

2020 ◽

Vol 13 (12) ◽

pp. 2863

Author(s):

Pavel Reiterman ◽

Roman Jaskulski ◽

Wojciech Kubissa ◽

Ondřej Holčapek ◽

Martin Keppert

Keyword(s):

Fly Ash ◽

Rational Design ◽

Cementitious Materials ◽

Supplementary Cementitious Materials ◽

Limestone Powder ◽

Experimental Program ◽

Initial Surface ◽

Freeze Thaw ◽

Mineral Additive

Self-compaction concrete (SCC) is ranked among the main technological innovations of the last decades. Hence, it introduces a suitable possibility for further utilization of supplementary cementitious materials (SCM) in terms of sustainable development. The aim of the work is the assessment of a new approach to binder design, which takes into consideration the activity of the used mineral additive. The proposed approach, which allows a systematic design of a binding system with varied properties of the used mineral additive, was studied on ternary blends consisting of Portland cement (PC), limestone powder and fly ash (FA). The verification was conducted on SCC mixtures in terms of their workability, mechanical properties and the most attention was paid to long-term durability. The long-term durability was assessed on the basis of shrinkage measurement, freeze-thaw resistance and permeability tests including initial surface absorption, chloride migration, water penetration and an accelerated carbonation test, which was compared with the evolution of carbonation front in normal conditions. The durability of studied mixtures was evaluated by using durability loss index, which allow general assessment on the basis of multiple parameters. The carbonation resistance had a dominant importance on the final durability performance of studied mixtures. The experimental program revealed that the proposed design method is reliable only in terms of properties in fresh state and mechanical performance, which were similar with control mixture. Despite suitable results of freeze-thaw resistance and shrinkage, an increasing amount of fly ash in terms of the new design concept led to a fundamental increase of permeability and thus to decay of long-term durability. Acceptable properties were achieved for the lowest dosage of fly ash.

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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

Applied Sciences ◽

10.3390/app10103572 ◽

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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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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Mechanical Properties of Cement-Treated Soil Mixed with Cellulose Nanofibre

Applied Sciences ◽

10.3390/app11146425 ◽

2021 ◽

Vol 11 (14) ◽

pp. 6425

Author(s):

Hidenori Takahashi ◽

Shinya Omori ◽

Hideyuki Asada ◽

Hirofumi Fukawa ◽

Yusuke Gotoh ◽

...

Keyword(s):

Mechanical Properties ◽

Flexural Strength ◽

Geotechnical Engineering ◽

Strength Development ◽

Soft Ground ◽

Wood Cellulose ◽

Treated Soil ◽

Made In ◽

Cement Treatment

Cellulose nanofibre (CNF), a material composed of ultrafine fibres of wood cellulose fibrillated to nano-order level, is expected to be widely used because of its excellent properties. However, in the field of geotechnical engineering, almost no progress has been made in the development of techniques for using CNFs. The authors have focused on the use of CNF as an additive in cement treatment for soft ground, where cement is added to solidify the ground, because CNF can reduce the problems associated with cement-treated soil. This paper presents the results of a study on the method of mixing CNF, the strength and its variation obtained by adding CNF, and the change in permeability. CNF had the effect of mixing the cement evenly and reducing the variation in the strength of the treated soil. The CNF mixture increased the strength at the initial age but reduced the strength development in the long term. The addition of CNF also increased the flexural strength, although it hardly changed the permeability.

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Use of Treated Non-Ferrous Metallurgical Slags as Supplementary Cementitious Materials in Cementitious Mixtures

Applied Sciences ◽

10.3390/app11094028 ◽

2021 ◽

Vol 11 (9) ◽

pp. 4028

Author(s):

Asghar Gholizadeh Vayghan ◽

Liesbeth Horckmans ◽

Ruben Snellings ◽

Arne Peys ◽

Priscilla Teck ◽

...

Keyword(s):

Mechanical Performance ◽

Cementitious Materials ◽

Supplementary Cementitious Materials ◽

Partial Replacement ◽

Strength Development ◽

Supplementary Cementitious Material ◽

Performance Requirements ◽

Metallurgical Slags ◽

Leaching Behaviour ◽

Kinetics Of

This research investigated the possibility of using metallurgical slags from the copper and lead industries as partial replacement for cement. The studied slags were fayalitic, having a mainly ferro-silicate composition with minor contents of Al2O3 and CaO. The slags were treated at 1200–1300 °C (to reduce the heavy metal content) and then granulated in water to promote the formation of reactive phases. A full hydration study was carried out to assess the kinetics of reactions, the phases formed during hydration, the reactivity of the slags and their strength activity as supplementary cementitious material (SCM). The batch-leaching behaviour of cementitious mixtures incorporating treated slags was also investigated. The results showed that all three slags have satisfactory leaching behaviour and similar performance in terms of reactivity and contribution to the strength development. All slags were found to have mediocre reactivity and contribution to strength, especially at early ages. Nonetheless, they passed the minimum mechanical performance requirements and were found to qualify for use in cement.

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New Approach for the Determination of Radiological Parameters on Hardened Cement Pastes with Coal Fly Ash

Materials ◽

10.3390/ma14030475 ◽

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 ◽

...

Keyword(s):

Fly Ash ◽

Activity Concentration ◽

Gamma Ray ◽

Coal Fly Ash ◽

Cementitious Materials ◽

New Method ◽

Supplementary Cementitious Materials ◽

Hardened Cement ◽

Cement Pastes ◽

Activity Concentrations

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.

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