4.7 Article

Effect of active MgO on the hydration kinetics characteristics and microstructures of alkali-activated fly ash-slag materials

Related references

Note: Only part of the references are listed.
Article Construction & Building Technology

Influence of reactivity and dosage of MgO expansive agent on shrinkage and crack resistance of face slab concrete

Lei Wang et al.

Summary: This study systematically investigated the effects of MgO on the shrinkage and crack resistance of face slab concrete. It was found that adding the appropriate amount of MgO can compensate for a certain proportion of shrinkage and improve crack resistance, with the reactive MgO (M60) performing the best and the weak reactive MgO (M300) reducing crack resistance.

CEMENT & CONCRETE COMPOSITES (2022)

Article Construction & Building Technology

Degradation mechanism of hybrid fly ash/slag based geopolymers exposed to elevated temperatures

Y. Luo et al.

Summary: This study investigated the physicochemical properties of alkali-activated fly ash/GGBS (AAFS) up to 800 degrees C, revealing a linear relationship between crack density and ultrasonic pulse velocity. The addition of slag into geopolymers was found to reduce geopolymeric behaviors but further aggravate thermal damage under high temperatures. Conceptual models of AAF and AAFS were proposed to explain the degradation mechanism of low slag contained geopolymers.

CEMENT AND CONCRETE RESEARCH (2022)

Article Construction & Building Technology

Effects of kaolin characteristics on the mechanical properties of alkali-activated binders

Ayman Ababneh et al.

Summary: This study investigated the potential use of six Kaolin samples for producing calcined kaolin-based alkali-activated binders. The chemical analysis revealed a wide range of Al2O3 content in the Kaolin samples, while the difference in SiO2 was minimal. The study found that Kaolin samples with higher pozzolanicity and higher Si/Al ratio were more effective in producing alkali-activated binders with higher compressive strength values.

CONSTRUCTION AND BUILDING MATERIALS (2022)

Review Construction & Building Technology

Heat evolution of alkali-activated materials: A review on influence factors

Rosnita Mohamed et al.

Summary: This review discusses the use of alkali-activated materials as alternatives to ordinary Portland cement in construction. It highlights the heat evolution during alkali activation and factors influencing heat evolution, emphasizing the importance of understanding heat evolution in the alkali activation process.

CONSTRUCTION AND BUILDING MATERIALS (2022)

Article Materials Science, Ceramics

Early hydration properties and microstructure evolutions of MgO-activated slag materials at different curing temperatures

Hongqiang Ma et al.

Summary: This study investigates the effects of different curing temperatures and MgO types on the early hydration properties and microstructure of MgO-activated slag. The results show that high-temperature curing significantly improves the compressive strength of the specimens, with different MgO types having different optimal curing temperatures. Furthermore, the study reveals a relationship between the mechanical properties, pore structure characteristics, and hydration products.

CERAMICS INTERNATIONAL (2022)

Article Construction & Building Technology

Numerical study on cracking and its effect on chloride transport in concrete subjected to external load

Qing-feng Liu et al.

Summary: This study presents a multi-species and multi-phase model considering the time-dependent cracking in concrete. The crack propagation and chloride diffusion are coupled by statistical learning approach, and the effect of the electrostatic potential on multi-species transport is considered. The validity of the model is verified against third-party experiments, and the impacts of different crack characteristics and environmental factors on chloride transport are discussed.

CONSTRUCTION AND BUILDING MATERIALS (2022)

Article Construction & Building Technology

Drying shrinkage characteristics and mechanism primary exploration of MgO-slag mortars

Hongqiang Ma et al.

Summary: This study investigates the effects of different types and contents of MgO on the properties of MgO-slag mortars and pastes, as well as the mechanism of drying shrinkage. The results show that increasing MgO activities and contents can decrease the setting time and increase the compressive strength. The compressive strength advantage of high-activity MgO is mainly seen in the early stage, while higher contents of S-MgO exhibit higher compressive strength advantage in the later stage. Additionally, the study finds that intraparticle porosity, interparticle porosity, and MgO particle size are important factors affecting the drying shrinkage. These findings provide valuable insights for the preparation of cementing materials with no length change using MgO activator.

CONSTRUCTION AND BUILDING MATERIALS (2022)

Article Construction & Building Technology

Fly ash-GGBS geopolymer in boron environment: A study on rheology and microstructure by ATR FT-IR and MAS NMR

T. Revathi et al.

Summary: The study focuses on the use of borax composite sodium silicate activator in geopolymerization, showing advantages in setting time and workability without affecting compressive strength. The borax composite pastes display shear thinning behavior and fit well with the Bingham model. Microstructural changes and spectral analysis reveal specific alterations upon borax addition.

CONSTRUCTION AND BUILDING MATERIALS (2021)

Article Construction & Building Technology

Effects of alkali dosage and silicate modulus on autogenous shrinkage of alkali-activated slag cement paste

Weiwei Chen et al.

Summary: The study reveals that a decrease in alkali dosage increases the autogenous shrinkage of AASC paste, while increasing Ms enhances autogenous shrinkage within a certain range but decreases it beyond a certain threshold.

CEMENT AND CONCRETE RESEARCH (2021)

Article Construction & Building Technology

Effect of reactive MgO on hydration and properties of alkali-activated slag pastes with different activators

Juan He et al.

Summary: The type of activator used significantly affects the properties of alkali-activated slag cement. Reactive MgO has different effects on AAS cement depending on the activator used. The addition of reactive MgO decreases the fluidity and setting time of AAS paste, while increasing the compressive strength in certain activators. Reactive MgO also enhances the hydration process and promotes the formation of more hydration products, leading to densification of the AAS matrix.

CONSTRUCTION AND BUILDING MATERIALS (2021)

Article Construction & Building Technology

Properties and mechanism of the compound MgO expansive agent (CMEA) produced by calcining the mixture of dolomite and serpentine tailings

Fengze Cao et al.

Summary: This study proposes a new method to produce compound MgO expansive agents using cheap tailings. The hydration activity of CMEA decreases with the rise of calcining temperature, and incorporating 20% CMEA into cement slightly reduces mechanical strength while significantly increasing volume expansion.

CONSTRUCTION AND BUILDING MATERIALS (2021)

Article Construction & Building Technology

Effect of metakaolin on the autogenous shrinkage of alkali-activated slag-fly ash paste

Zhenming Li et al.

Summary: The addition of metakaolin can significantly reduce the autogenous shrinkage of alkali-activated slag-fly ash paste, lower the compressive and flexural strength of the paste.

CONSTRUCTION AND BUILDING MATERIALS (2021)

Article Construction & Building Technology

E Hydration properties of alkali-activated fly ash/slag binders modified by MgO with different reactivity

Z. Wang et al.

Summary: The study examines the roles of MgO in alkali-activated materials and its effects on compressive strengths and hydration properties, revealing that highly reactive MgO can enhance hydration degree and promote incorporation of Na and Mg atoms into binding chains. The hydration mechanism of reactive MgO in alkali-activated fly ash and slag blended materials is discussed.

JOURNAL OF BUILDING ENGINEERING (2021)

Article Construction & Building Technology

Hydration kinetics of cement-calcined activated bauxite tailings composite binder

Longfei Zhou et al.

Summary: The study found that increasing the bauxite tailings content leads to an increase in the induction period of the composite binder, while hydration heat increases with both the tailings content and selection frequency. The kinetics model can effectively simulate the hydration process of cement-bauxite tailings composite binder.

CONSTRUCTION AND BUILDING MATERIALS (2021)

Article Construction & Building Technology

Experimental research on magnesium phosphate cements modified by red mud

Yuantao Liu et al.

CONSTRUCTION AND BUILDING MATERIALS (2020)

Article Construction & Building Technology

Improvement of early strength of fly ash-slag based one-part alkali activated mortar

Syed Farasat Ali Shah et al.

CONSTRUCTION AND BUILDING MATERIALS (2020)

Article Construction & Building Technology

Natural carbonation-induced phase and molecular evolution of alkali-activated slag: Effect of activator composition and curing temperature

Hailong Ye et al.

CONSTRUCTION AND BUILDING MATERIALS (2020)

Article Construction & Building Technology

Hydration kinetics and products of MgO-activated blast furnace slag

Solmoi Park et al.

CONSTRUCTION AND BUILDING MATERIALS (2020)

Article Construction & Building Technology

Multiscale micromechanical analysis of alkali-activated fly ash-slag paste

Guohao Fang et al.

CEMENT AND CONCRETE RESEARCH (2020)

Article Construction & Building Technology

Durability evolution and associated micro-mechanisms of carbonated reactive MgO-fly ash solidified sludge from East Lake, China

Dongxing Wang et al.

CONSTRUCTION AND BUILDING MATERIALS (2019)

Article Construction & Building Technology

Study on the drying shrinkage of alkali-activated coal gangue-slag mortar and its mechanisms

Ma Hongqiang et al.

CONSTRUCTION AND BUILDING MATERIALS (2019)

Article Construction & Building Technology

Isothermal calorimetry and in-situ XRD study of the NaOH activated fly ash, metakaolin and slag

Zengqing Sun et al.

CEMENT AND CONCRETE RESEARCH (2018)

Article Construction & Building Technology

Hydration characteristics and expansive mechanism of MgO expansive agents

Fengze Cao et al.

CONSTRUCTION AND BUILDING MATERIALS (2018)

Article Construction & Building Technology

Preparation and characterization of coal gangue geopolymers

Yi Cheng et al.

CONSTRUCTION AND BUILDING MATERIALS (2018)

Article Construction & Building Technology

Effect of high MgO content on the performance of alkali-activated fine slag under water and air curing conditions

Chao-Lung Hwang et al.

CONSTRUCTION AND BUILDING MATERIALS (2018)

Article Materials Science, Multidisciplinary

Alkali-activated grouts with incorporated fly ash: From NMR analysis to mechanical properties

Anass Cherki El Idrissi et al.

MATERIALS TODAY COMMUNICATIONS (2018)

Article Thermodynamics

Kinetics study of geopolymerization of fly ash using isothermal conduction calorimetry

S. K. Nath et al.

JOURNAL OF THERMAL ANALYSIS AND CALORIMETRY (2017)

Article Materials Science, Multidisciplinary

Portland Cement Hydration Behavior at Low Temperatures: Views from Calculation and Experimental Study

Zhuangzhuang Liu et al.

ADVANCES IN MATERIALS SCIENCE AND ENGINEERING (2017)

Article Thermodynamics

Early hydration properties of composite binder containing limestone powder with different finenesses

Han Fanghui et al.

JOURNAL OF THERMAL ANALYSIS AND CALORIMETRY (2016)

Article Construction & Building Technology

Phase evolution of C-(N)-A-S-H/N-A-S-H gel blends investigated via alkali-activation of synthetic calcium aluminosilicate precursors

Brant Walkley et al.

CEMENT AND CONCRETE RESEARCH (2016)

Article Construction & Building Technology

Mechanical properties of alkali activated flyash/Kaolin based geopolymer concrete

F. N. Okoye et al.

CONSTRUCTION AND BUILDING MATERIALS (2015)

Article Construction & Building Technology

New Pore Structure Assessment Methods for Cement Paste

Hongyan Ma et al.

JOURNAL OF MATERIALS IN CIVIL ENGINEERING (2015)

Article Construction & Building Technology

Retracted: Effect of Reactive Magnesium Oxide on Properties of Alkali-Activated Slag-Cement Pastes

H. A. Abdel-Gawwad

JOURNAL OF MATERIALS IN CIVIL ENGINEERING (2014)

Article Construction & Building Technology

MgO content of slag controls phase evolution and structural changes induced by accelerated carbonation in alkali-activated binders

Susan A. Bernal et al.

CEMENT AND CONCRETE RESEARCH (2014)

Review Construction & Building Technology

MgO expansive cement and concrete in China: Past, present and future

Liwu Mo et al.

CEMENT AND CONCRETE RESEARCH (2014)

Article Construction & Building Technology

Strength and drying shrinkage of reactive MgO modified alkali-activated slag paste

Fei Jin et al.

CONSTRUCTION AND BUILDING MATERIALS (2014)

Article Materials Science, Ceramics

High-Resolution X-ray Diffraction and Fluorescence Microscopy Characterization of Alkali-Activated Slag-Metakaolin Binders

Susan A. Bernal et al.

JOURNAL OF THE AMERICAN CERAMIC SOCIETY (2013)

Article Construction & Building Technology

Influence of slag chemistry on the hydration of alkali-activated blast-furnace slag - Part I: Effect of MgO

M. Ben Haha et al.

CEMENT AND CONCRETE RESEARCH (2011)

Proceedings Paper Construction & Building Technology

Effect of Fly Ash, MgO and Curing Solution on the Chemical Shrinkage of Alkali-Activated Slag Cement

Yonghao Fang et al.

ADVANCES IN BUILDING MATERIALS, PTS 1-3 (2011)

Article Construction & Building Technology

Effect of alkalis on fresh C-S-H gels. FTIR analysis

I. Garcia Lodeiro et al.

CEMENT AND CONCRETE RESEARCH (2009)

Article Chemistry, Applied

Effect of the Sio2/Na2O ratio on the alkali activation of fly ash.: Part II:: 29Si MAS-NMR Survey

M. Criado et al.

MICROPOROUS AND MESOPOROUS MATERIALS (2008)

Article Materials Science, Multidisciplinary

Structural studies of geopolymers by 29Si and 21Al MAS-NMR

PS Singh et al.

JOURNAL OF MATERIALS SCIENCE (2005)

Article Construction & Building Technology

A conceptual model of the cement hydration process

R Krstulovic et al.

CEMENT AND CONCRETE RESEARCH (2000)