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Correlation between Slag Reactivity and Cement Paste Properties: The Influence of Slag Chemistry

Zhang, Yu (author), Copuroglu, Oguzhan (author)

The properties of slag-rich cement paste are fundamentally associated with slag chemistry. In the present research, 10 slags covering the common chemistry range, including eight synthetic slags of CaO-SiO2-Al2O3-MgO system and two commercial slags, were adopted to evaluate the influence of slag composition on the early (7 days) and later (3...

journal article 2023

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Effect of P₂O₅ incorporated in slag on the hydration characteristics of cement-slag system

Zhang, Y. (author), Chen, Y. (author), Copuroglu, Oguzhan (author)

This paper presents the influence of P₂O₅ incorporated in slag on the hydration characteristics of cement-slag system. It was found that the gradual addition of phosphorus oxide in slag did not change overall mineralogy of the hydration products. Except hydration retardation in the dormant stage, chemically bound water...

journal article 2023

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Some Critical Reflections on the SEM-EDS Microanalysis of the Hydrotalcite-like Phase in Slag Cement Paste

Zhang, Y. (author), Saravanakumar, Karthikeyan (author), Copuroglu, Oguzhan (author)

For a better understanding of the hydrotalcite-like phase with SEM-EDS microanalysis, the present research paid special attention to the data acquisition and interpretation of this technique. A lower Mg/Al ratio was obtained when using a higher accelerating voltage, and a beam energy of 10 kV was more appropriate than 15 kV for investigation...

journal article 2023

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3-Dimensional insight into zonation within slag rims of aged blended cement

Zhang, Y. (author), Copuroglu, Oguzhan (author)

Through the integration of SEM-BSE and TEM, we gained a comprehensive 3-dimensional understanding of different distribution patterns of inner hydration products of slag. For fully hydrated small slag grains, two distinct sub-zones were formed in the rims. Lath-like, well-crystalline hydrotalcite-like crystals were found to precipitate, grow,...

journal article 2023

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Characterizing two types of zonation within slag rims of aged alkali-activated slag pastes through SEM and TEM

Zhang, Y. (author), Zhang, Shizhe (author), Liu, C. (author), Copuroglu, Oguzhan (author)

In this paper, the authors characterized two types of zonation within slag rims in aged alkali-activated slag (AAS) systems through SEM and TEM technology. These two elemental zonation were closely related to the pore structure of AAS pastes, thus providing strong implication for the transport- and durability-related performance of AAS...

journal article 2023

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Improving structural build-up of limestone-calcined clay-cement pastes by using inorganic additives

Chen, Y. (author), Zhang, Y. (author), He, S. (author), Liang, X. (author), Schlangen, E. (author), Copuroglu, Oguzhan (author)

In 3D concrete printing, fast structuration is a prerequisite for ideal buildability. This paper aims to study the impact of inorganic additives, i.e., CaCl₂ and gypsum, on structural build-up and very early-age hydration of limestone-calcined clay-cement (LC3) pastes within the first 70–80 min. Results show that, increasing the...

journal article 2023

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Effect of Al₂O₃ content in slag on the relationship between slag reactivity and carbonation resistance

Zhang, Y. (author), Copuroglu, Oguzhan (author)

To understand the influence of slag chemistry on the carbonation resistance of slag-rich cement, this paper explored the carbonation characteristics of blended cement systems with different Al₂O₃ contents in slag through accelerated carbonation test. Irrespective of slag chemistry, three main CO₂ binding...

journal article 2023

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Can superabsorbent polymers be used as rheology modifiers for cementitious materials in the context of 3D concrete printing?

Chen, Y. (author), Liang, M. (author), Zhang, Y. (author), Li, Z. (author), Šavija, B. (author), Schlangen, E. (author), Copuroglu, Oguzhan (author)

Autogenous shrinkage may be a critical issue concerning the use of limestone-calcined clay-cement (LC3) in high-performance concrete and 3D printable cementitious materials, which have relatively low water to binder (W/B) ratio. Adding an internal curing agent, i.e., superabsorbent polymer (SAP), could be a viable solution in this context....

journal article 2023

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Rheology control of limestone calcined clay cement pastes by modifying the content of fine-grained metakaolin

Chen, Y. (author), Zhang, Y. (author), He, S. (author), Liang, M. (author), Zhang, Yamei (author), Schlangen, E. (author), Copuroglu, Oguzhan (author)

Limestone-calcined clay-cement (LC3), as one of the most promising sustainable cements, has been under development over the past decade. However, many uncertainties remain regarding its rheological behaviors, such as the metakaolin content of calcined clay. This study aims to investigate the effect of increasing the content of fine-grained...

journal article 2023

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Fresh properties of limestone-calcined clay-slag cement pastes

Chen, Y. (author), Zhang, Y. (author), Šavija, B. (author), Copuroglu, Oguzhan (author)

Formulation of quaternary blended system containing ordinary Portland cement or clinker, slag, limestone and calcined clay (LC2) appeared to be a viable approach to developing low-clinker cements without severely sacrificing mechanical performance at later ages. This paper investigates the effect of two material parameters, i.e., LC2-to-slag...

journal article 2023

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Micro-Mechanical Properties of Slag Rim Formed in Cement–Slag System Evaluated by Nanoindentation Combined with SEM

Zhang, Y. (author), Liang, M. (author), Gan, Y. (author), Copuroglu, Oguzhan (author)

Slag rim mainly consists of secondary precipitations such as C–S–H gel phase and hydrotalcite-like phase, which originate from the hydration of slag. In this paper, the micro-mechanical properties of slag rim were characterized by nanoindentation in combination with SEM. It was found that, compared to the C–S–H gel phase, slag rim showed about a...

journal article 2022

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The role of hydrotalcite-like phase and monosulfate in slag cement paste during atmospheric and accelerated carbonation

Zhang, Y. (author), Copuroglu, Oguzhan (author)

This paper identified carbonation products in the slag-rich cementitious systems upon three different exposure conditions, namely, long term exposure in the field, indoor natural exposure, and accelerated carbonation testing. Overall, mineralogy of the carbonation products was found to be fundamentally similar under different exposure...

journal article 2022

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Effect of slags of different origins and the role of sulfur in slag on the hydration characteristics of cement-slag systems

Zhang, Y. (author), Schlangen, E. (author), Copuroglu, Oguzhan (author)

The effect of slag of different origins (synthetic slag produced in the laboratory and commercial slag collected from different steel factories) with comparable chemical composition, amorphous content and particle size distribution, on the hydration characteristics of slag cement was investigated. In order to study the effect of sulfur in...

journal article 2022

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Role of the grain size on the hydration characteristics of slag in an aged field concrete

Zhang, Y. (author), Copuroglu, Oguzhan (author)

This paper studies chemical composition of partially and fully hydrated slag grains in a (nearly) 40-year-old field concrete from the Netherlands. The concrete samples were assumed to be sufficiently aged to contain fully hydrated slag grains as well as partially hydrated large slag particles with thick rims. Our analysis showed that three...

journal article 2022

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Early age hydration of model slag cement: Interaction among C₃S, gypsum and slag with different Al₂O₃ contents

Zhang, Y. (author), Wan, Z. (author), Miranda de Lima Junior, L.C. (author), Copuroglu, Oguzhan (author)

A deeper insight into SO₃/Al₂O₃ ratio including the contribution of alumina in slag at early age is required to ensure a properly sulfated slag cement. In this paper, to investigate the effect of gypsum and alumina of slag, emphasis was laid on the hydration characteristics of C₃S-gypsum-slag system...

journal article 2022

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Effect of MgO content on the quantitative role of hydrotalcite-like phase in a cement-slag system during carbonation

Zhang, Y. (author), Liang, M. (author), Gan, Y. (author), Copuroglu, Oguzhan (author)

This paper reports the carbonation characteristics of a cement-slag system exposed to accelerated carbonation testing, and its improved carbonation resistance with the increasing MgO content in blast furnace slag, in which hydrotalcite-like phase plays a key role. Our research showed that the hydrotalcite-like phase started to carbonate upon...

journal article 2022

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The effect of slag chemistry on CO₂ binding capacity of C₃S-slag (-gypsum) system

Zhang, Y. (author), Copuroglu, Oguzhan (author)

In this paper, the authors investigated the correlation between slag chemistry and CO₂ binding capacity of the blended system. To simplify the composition of mixture, model paste containing C₃S, slag covering the common composition range and gypsum was employed. After accelerated carbonation test, three CO₂...

journal article 2022

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EDS Microanalysis of Unhydrated Blast Furnace Slag Grains in Field Concrete with Different Service Life

Zhang, Y. (author), Saravanakumar, Karthikeyan (author), Copuroglu, Oguzhan (author)

Because the essential quality metrics of blast furnace slag are based on its oxide composition, the determination of chemical compositions of unhydrated slag grains in an aged concrete could be useful for understanding its past performance and in predicting the remaining service life of existing slag-bearing concrete. In this research, the...

journal article 2022

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The effect of slag chemistry on the reactivity of synthetic and commercial slags

Zhang, Y. (author), Zhang, Shizhe (author), Chen, Y. (author), Copuroglu, Oguzhan (author)

In this paper, both synthetic slag and commercial slag covering the common composition range were employed to estimate the correlation between slag chemistry and reactivity through hydraulicity and dissolution tests. It was found that slag reactivity was favorably affected by increasing Al₂O₃ and MgO contents, while the...

journal article 2022

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A study of the elastic moduli and chemical composition of corrosion product naturally-generated due to chlorides through nano-indentation and energy dispersive X-ray spectrometry (EDS)

Rossi, E. (author), Zhang, Hongzhi (author), Nijland, Timo G. (author), Copuroglu, Oguzhan (author), Polder, R.B. (author), Šavija, B. (author)

An important input parameter for numerical models that simulate cracking of the concrete cover due to reinforcement corrosion is the Elastic modulus of corrosion product (Ecp). Despite its relevance, Ecp is subject of significant variations according to the values reported in the literature, which vary from less than 100 MPa up to 360 GPa....

conference paper 2021