Zhenguo Shi
Swiss Federal Laboratories for Materials Science and Technology
Alkali–silica reactionCarbonationMetakaolinMortarComposite materialInorganic chemistryChemistryMaterials scienceAlkali metalScanning electron microscopeSilicateChlorideCementitiousPortland cementCompressive strengthChemical engineeringAlkalinityCementFly ashSlag
48Publications
20H-index
1,326Citations
Publications 42
Newest
#1Guoqing Geng (NUS: National University of Singapore)H-Index: 19
#2Solène Barbotin (EPFL: École Polytechnique Fédérale de Lausanne)H-Index: 1
Last. Rainer Dähn (Paul Scherrer Institute)H-Index: 24
view all 9 authors...
Abstract The ASR products in concrete have various chemical compositions. It is yet unclear whether and how these products develop micro-expansion upon moisture ingress. This paper presents a 3D in-situ observation of the crystallography and volume change of an ASR-product-filled vein under varying relative-humidity (R.H.). The vein was observed to contain two layered nano-crystalline phases with distinct basal spacings, and was distributed heterogeneously in space. When R.H. changed from 10% to...
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#1Zhenguo Shi (Empa: Swiss Federal Laboratories for Materials Science and Technology)H-Index: 20
#2Bin Ma (Empa: Swiss Federal Laboratories for Materials Science and Technology)H-Index: 13
Last. Barbara Lothenbach (Empa: Swiss Federal Laboratories for Materials Science and Technology)H-Index: 78
view all 3 authors...
Abstract The use of Al-rich supplementary cementitious materials can effectively reduce the expansion of concrete caused by alkali-silica reaction (ASR). However, the role of Al in mitigating the formation and structure of ASR products is only poorly understood, since direct investigation of the reaction in the micro-scale veins of aggregates is difficult. Recent successful synthesis of ASR products provides a unique opportunity to directly assess the role of Al in ASR. In this study, the effect...
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Dr. Isabel Martins was missing from the RILEM membership list that was published in the original article. The original article has been corrected.
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#1Zhenguo ShiH-Index: 20
#2Barbara LothenbachH-Index: 78
Using Al-rich supplementary cementitious materials to partially replace Portland cement is a well-established empirical approach to mitigate expansion of concrete caused by alkali-silica reaction (ASR). However, the mechanisms behind it are still not completely understood. Synthesis of ASR products in the laboratory provides a unique opportunity to better understand the conditions and mitigation mechanism of ASR. This study focusses on the synthesis of an 10.8 A ASR product, which is structurall...
#1Guoqing GengH-Index: 19
#2Zhenguo ShiH-Index: 20
Last. Rainer DähnH-Index: 4
view all 6 authors...
#1Tulio Honorio (Université Paris-Saclay)H-Index: 10
#2Ornella M. Chemgne Tamouya (Université Paris-Saclay)H-Index: 2
Last. Zhenguo Shi (Empa: Swiss Federal Laboratories for Materials Science and Technology)H-Index: 20
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We perform molecular simulations to characterize the structure and the thermo-mechanical behavior of crystalline alkali-silica reaction (ASR) products, which are layered silicate analogous to shlykovite. As charge-balancing cations, we study Na and K (the most relevant alkali involved in ASR) as well as Li (relevant for ASR therapy) and Cs (relevant for nuclear applications). For the first time, the thermal and elastic properties of these crystalline products are computed using molecular simulat...
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#1Zhenguo Shi (Empa: Swiss Federal Laboratories for Materials Science and Technology)H-Index: 20
#2Solmoi Park (Pukyong National University)H-Index: 17
Last. Andreas Leemann (Empa: Swiss Federal Laboratories for Materials Science and Technology)H-Index: 28
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Abstract Three types of alkali-silica reaction (ASR) products, i.e., crystalline K-shlykovite, Na-shlykovite and nano-crystalline ASR-P1, have recently been synthesized at 80 °C. It is critical to verify the formation of these ASR products in concrete in order to transfer the knowledge of ASR gained from the synthesized products to the ones formed in field concrete. Therefore, ASR products formed in concrete exposed to KOH, NaOH or mixture of KOH/NaOH solution at 60 and 80 °C are analyzed using ...
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#1Andreas Leemann (Empa: Swiss Federal Laboratories for Materials Science and Technology)H-Index: 28
#2Zhenguo Shi (Empa: Swiss Federal Laboratories for Materials Science and Technology)H-Index: 20
Last. Jan Lindgård (SINTEF)H-Index: 7
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Abstract Amorphous and crystalline alkali silica reaction (ASR) products formed in aggregates of two different concrete mixtures exposed to the concrete prim test both at 38 °C and 60 °C have been analysed by scanning electron microscope with energy dispersive X-ray spectroscopy and by Raman microscopy. Additionally, amorphous ASR products were synthesized and analysed with Raman microscopy and 29Si nuclear magnetic resonance. Amorphous ASR products display a higher Na/K-ratio than crystalline o...
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#2Barbara Lothenbach (Empa: Swiss Federal Laboratories for Materials Science and Technology)H-Index: 78
Last. Nele De Belie (UGent: Ghent University)H-Index: 63
view all 27 authors...
Blended cements, where Portland cement clinker is partially replaced by supplementary cementitious materials (SCMs), provide the most feasible route for reducing carbon dioxide emissions associated with concrete production. However, lowering the clinker content can lead to an increasing risk of neutralisation of the concrete pore solution and potential reinforcement corrosion due to carbonation. carbonation of concrete with SCMs differs from carbonation of concrete solely based on Portland cemen...
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#1Tulio Honorio (Université Paris-Saclay)H-Index: 10
#2Ornella M. Chemgne Tamouya (Université Paris-Saclay)H-Index: 2
Last. Alexandra Bourdot (Université Paris-Saclay)H-Index: 5
view all 4 authors...
Abstract There is no consensus on the physical origin of alkali-silica reaction (ASR) damage in concrete. Atomic-level detail on the intermolecular interactions of ASR products with water is critical to understand the development and to propose solutions to mitigate ASR. We combine molecular dynamics and Monte Carlo simulations to model ASR products under sorption. The hydration of shlykovite, a naturally occurring phyllosilicate structurally similar to ASR products, is analyzed with atomic-leve...
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