Influence of Cements Containing Calcareous Fly Ash as a Main Component Properties of Fresh Cement Mixtures

Gołaszewski, Jacek; Kostrzanowska–Siedlarz, Aleksandra; Ponikiewski, Tomasz; Miera, Patrycja

doi:10.1088/1757-899x/245/2/022099

Cited by 6 publications

(7 citation statements)

References 9 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…The initial and final setting times of concrete are very important for efficient construction of concrete pavement, as curing, tining, and saw cutting are dependent on setting times. Moreover, a very long setting time can cause plastic shrinkage cracks, as the amount of plastic shrinkage is directly proportional to the final setting time (Gołaszewski et al 2017). There are multiple methods to measure setting times such as the vicat needle test (ASTM C191 2019), ultrasound wave propagation (Öztürk et al 2006;Reinhardt, Große, and Herb 2000), calorimetry (Hu, Ge, and Wang 2014), and noncontact ultrasound (Tran andRoesler 2020, 2021).…”

Section: Setting Timementioning

confidence: 99%

High-volume Fly Ash Concrete for Pavements Findings: Volume 1

Baral¹,

Roesler²,

Ley³

et al. 2021

View full text Add to dashboard Cite

High-volume fly ash concrete (HVFAC) has improved durability and sustainability properties at a lower cost than conventional concrete, but its early-age properties like strength gain, setting time, and air entrainment can present challenges for application to concrete pavements. This research report helps with the implementation of HVFAC for pavement applications by providing guidelines for HVFAC mix design, testing protocols, and new tools for better quality control of HVFAC properties. Calorimeter tests were performed to evaluate the effects of fly ash sources, cement–fly ash interactions, chemical admixtures, and limestone replacement on the setting times and hydration reaction of HVFAC. To better target the initial air-entraining agent dosage for HVFAC, a calibration curve between air-entraining dosage for achieving 6% air content and fly ash foam index test has been developed. Further, a digital foam index test was developed to make this test more consistent across different labs and operators. For a more rapid prediction of hardened HVFAC properties, such as compressive strength, resistivity, and diffusion coefficient, an oxide-based particle model was developed. An HVFAC field test section was also constructed to demonstrate the implementation of a noncontact ultrasonic device for determining the final set time and ideal time to initiate saw cutting. Additionally, a maturity method was successfully implemented that estimates the in-place compressive strength of HVFAC through wireless thermal sensors. An HVFAC mix design procedure using the tools developed in this project such as the calorimeter test, foam index test, and particle-based model was proposed to assist engineers in implementing HVFAC pavements.

show abstract

Section: Setting Timementioning

confidence: 99%

High-volume Fly Ash Concrete for Pavements Findings: Volume 1

Baral¹,

Roesler²,

Ley³

et al. 2021

View full text Add to dashboard Cite

show abstract

“…Even then, the water demands remain higher than those of cement [2,6]. The high water demands of CFA make it difficult to obtain fresh concrete with the required stable workability in the long term, whether it is used as an additive to cement or as an additive to concrete [6,[12][13][14][15][16][17][18]. The processing of CFA solves this problem to some extent, but it should be noted that the use of ground CFA undoubtedly has a beneficial effect on the rheological properties of mortars and their variability [12,14,[16][17][18].…”

Section: Introductionmentioning

confidence: 99%

“…However, the experimental data on this topic has been limited. In general, to obtain a specific workability of fresh concrete with CFA, it is necessary to use more P or SP than for of the corresponding compositions without CFA [16][17][18][19][20][21][22]. This is likely due primarily to the higher water demand of fresh concrete with CFA.…”

Section: Introductionmentioning

confidence: 99%

“…Consequently, there is a smaller amount of free water in the mixture [23]. The potentially lower efficiency of P and SP in the presence of CFA is indicated by the faster loss of workability of mixes with CFA [6], but such effects do not occur in every case [16,17,22]. To date, there has been no in-depth study on how different types of P and SP work with CFA with different properties, both in terms of the primary effect-the rheological properties of the mortars-and the secondary effects-setting time, air entrainment, or hydration heat.…”

Section: Introductionmentioning

confidence: 99%

See 1 more Smart Citation

The Influence of Calcareous Fly Ash on the Effectiveness of Plasticizers and Superplasticizers

Gołaszewski

Ponikiewski

Kostrzanowska–Siedlarz

et al. 2020

Materials

Self Cite

View full text Add to dashboard Cite

Due to the rational shaping of the environment and the management of environmental resources in accordance with the principle of sustainable development, calcareous fly ash (CFA)—high-calcium as a by-product of lignite combustion—is a valuable addition to concrete. This additive, however, due to its high-water demand lowers the workability of the concrete mix, which is a problem, especially in the first 90 min after mixing the components of the mix. In order to meet this challenge, plasticizers (P) and superplasticizers (SP) for concrete are used with various effects which are designed to reduce the yield value and plastic viscosity. To check the technical efficiency of admixtures P and SP with different chemical bases, the main objective of this research was to investigate the influence of raw and ground CFA on the rheological properties and other side effects of admixtures, such as the amount of air in the mixture and the amount of heat of hydration. The use of P, particularly SP, effectively improves the workability of the mortar containing CFA, especially ground CFA. With these admixtures, it is possible to obtain mortars containing ground CFA with similar rheological properties to mortars without its addition. To obtain a specific workability of mortar with CFA, it is usually necessary to introduce a higher dose of P or SP than used for mortars without CFA. The presence of raw CFA does not alter the effectiveness of P and strongly reduces the effectiveness of SP. The reduced effectiveness of SP manifests primarily as a high workability lost. The presence of ground CFA does not change the effectiveness of P (or is higher). The effectiveness of the superplasticizer SNF (with a chemical base of naphthalene sulfonate) and PE (with a chemical base of polycarboxylate ether) is slightly lower or does not change. The effectiveness of the superplasticizer SMF (with a chemical base of melamine sulfonates) is significantly lower. We found that the presence of ash affects the efficiency of P and SP, while processing via the grinding of ash makes the effect negligible. These results are novel in both their cognitive and practical aspects.

show abstract

“…In pavement construction, setting time and strength gain is important for planning different construction activities such as tining, curing, saw-cutting of joints, and construction vehicle operation ( 12 , 13 ). A longer final setting time is also linked to the amount of plastic shrinkage cracks ( 14 ). Moreover, the quality and consistency of these alternative binders or higher cement replacement mixtures may not be as good as conventional PCC.…”

mentioning

confidence: 99%

Early Age Monitoring of High Cement Replacement Mixtures for Pavement

Baral

Roesler

2022

Transportation Research Record: Journal of the Transportation R

View full text Add to dashboard Cite

Decarbonization of concrete will require a combination of alternative binding materials and higher cement replacement rate with supplementary cementitious materials. Developing tools and methods that help engineers evaluate the properties of early age concrete pavement, such as setting time and strength gain, will be necessary to adopt new concrete mixes. Two concrete pavement test sections were constructed, a high early strength concrete mix with 25% (control) and 40% replacement of cement with fly ash (HVFAC), along with monitoring of the concrete’s setting time, saw-cut timing, and strength gain. A non-contact ultrasonic device was used to estimate setting time through measuring leaky Rayleigh wave energy transmission. The laboratory setting time of the control and HVFAC mix measured with the non-contact device was 5.5 h and 15 h, respectively, and agreed with measured isothermal calorimetry results. Further calorimeter tests showed that adding an accelerating admixture or replacing part of the cement with nano-limestone decreased the HVFAC setting time up to 4.4 h. The field setting time of the control mixture with the non-contact device measured 4.2 h, which was shorter than the laboratory estimate. Based only on the experience of construction personnel, saw-cutting for these mixtures was initiated too early and caused significant joint raveling, reinforcing the importance of in situ setting time measurement. The maturity method was successfully implemented with embedded wireless temperature sensors that rapidly and easily estimated the in-place compressive strength and improved opening time determination for concrete with high cement replacement levels, which are sensitive to the volume of supplementary cementitious materials, admixtures, and ambient conditions.

show abstract

Influence of Cements Containing Calcareous Fly Ash as a Main Component Properties of Fresh Cement Mixtures

Cited by 6 publications

References 9 publications

High-volume Fly Ash Concrete for Pavements Findings: Volume 1

High-volume Fly Ash Concrete for Pavements Findings: Volume 1

The Influence of Calcareous Fly Ash on the Effectiveness of Plasticizers and Superplasticizers

Early Age Monitoring of High Cement Replacement Mixtures for Pavement

Contact Info

Product

Resources

About