Publications de Karen Scrivener

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The formation of thaumasite was investigated with the progressive equilibrium approach (PEA). This approach experimentally simulates the conditions of various levels of sulfate addition in hardened cement pastes. The influence of limestone, time, C(3)A con ...

Various methods have been developed to synthesize C-S-H; however, these methods have only allowed for the successful production of pure-phase C-S-H with Ca:Si of 1.5 or less. Attempts to form higher Ca:Si ratios by these methods gives C-S-H (Ca:Si 1.5 or l ...

The mechanisms behind the expansion of samples immersed in solutions containing sulfate ions have been controversial. Expansion is believed to originate in the formation of ettringite, but it is not possible to find any direct correlation between these two ...

This paper describes a novel approach to the quantitative investigation of the impact of varying relative humidity (RH) and temperature on the structure and thermodynamic properties of salts and crystalline cement hydrates in different hydration states (i. ...

The durability of mortar and paste mixtures with respect to chloride ion ingress was investigated for binary blends of Portland Cement Calcined Clay, and ternary systems of Limestone Calcined Clay Cement (LC3). Five clays from various sources with differen ...

The microstructural aspects of iron sulfide degradation in dam concrete were investigated by scanning electron microscopy (SEM) and energy dispersive spectroscopy (EDS) in both dam concrete samples and laboratory concrete. The results show that iron sulfid ...

ASR affected concrete in real structures is usually subject to loads which affect the macroscopic expansion of the material. An experimental study was undertaken using sensors embedded in reactive and non-reactive samples loaded on modified creep frames. N ...

Valorisation of locally available clays for producing blended cements is crucial for a widespread adoption of sustainable binders incorporating these materials. In some places, clays can be intermixed with small amounts of iron sulfides, which could eventu ...

The aim of this study was to understand the origin of the variation in the hydraulic reactivity of ye'elimite systems. To this end, the hydration of two clinkers, one composed mainly of synthetic stoichiometric (C(4)A(3)(S) over bar) "Y" and the other of a ...

RILEM TC 267-TRM is studying tests for the reactivity supplementary cementitious materials (SCMs). In the first phase, the lime reactivity (LR) test, which is standardised in Indian standard (IS)-1727, gave promising correlations with 90-days cement mortar ...

The influence of temperature on the expansive behavior and microstructural damage of concrete due to the alkali-silica reaction (ASR) is studied experimentally by applying a new testing protocol, the Alkali-Wrapped Concrete Prism Test (AW-CPT). Early-stage ...

Efforts to tune the bulk physical properties of concrete are hindered by a lack of knowledge related to the atomic-level structure and growth of calcium silicate hydrate phases, which form about 50-60% by volume of cement paste. Here we describe the first ...

The macroscopic effects of ASR are linked to the damage state at the microstructure level. In this paper we used a combination of experiments and modelling to study the effect of aggregate size on the manifestation of ASR. There are two main ways in which ...

CO2 mineralization products are often heralded as having outstanding potentials to reduce CO2-eq. emissions. However, these claims are generally undermined by incomplete consideration of the life cycle climate change impacts, material properties, supply an ...

The content of individual amorphous supplementary cementitious materials (SCMs) in anhydrous and hydrated blended cements was quantified by the PONKCS [1] X-ray diffraction (XRD) method. The analytical precision and accuracy of the method were assessed thr ...

This study compares the influence of two limestone fineness on strength development and cement hydration. The replacement of clinker by 20% of fine limestone (d(v,50) = 2 mu m and SSA = 4,21 m(2)/g) gives similar strength development to PC up to 7 days. Fi ...

Progress in understanding hydration mechanisms of alite and Portland cement is reviewed. Up to the end of the induction period, dissolution rates determined by the undersaturation of the solution dominate the reaction, but, better understanding is needed a ...

The nanoscale morphology of, and pore water interactions in, calcium silicate hydrate (C-S-H), the active component of cement, remain uncertain. H-1 nuclear magnetic resonance (NMR) can fully characterize the nanoporosity of C-S-H in as-prepared material w ...

The reactions of dolomite with portlandite have been studied at well-spaced temperatures between 20 degrees C and 85 degrees C using XRD Rietveld, TG and SEM methods. The results show quantitatively the faster rates of reaction at higher temperature. Isoth ...

This study investigates the coupled substitution of metakaolin and limestone in Portland cement (PC). The mechanical properties were studied in mortars and the microstructural development in pastes by X-ray diffraction, thermogravimetry analysis, mercury i ...

Karen Scrivener

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A thermodynamic and experimental study of the conditions of thaumasite formation

A method for the reliable and reproducible precipitation of phase pure high Ca/Si ratio (>1.5) synthetic calcium silicate hydrates (C-S-H)

Mechanism of expansion of mortars immersed in sodium sulfate solutions

Methods to determine hydration states of minerals and cement hydrates

Performance of Limestone Calcined Clay Cement (LC3) with various kaolinite contents with respect to chloride transport

Physical and microstructural aspects of iron sulfide degradation in concrete

Effects of uniaxial stress on alkali-silica reaction induced expansion of concrete

Oxidation of pyrite (FeS2) and troilite (FeS) impurities in kaolinitic clays after calcination

Factors influencing the hydration kinetics of ye'elimite; effect of mayenite

Report of RILEM TC 267-TRM: Improvement and robustness study of lime mortar strength test for assessing reactivity of SCMs

Impact of temperature on expansive behavior of concrete with a highly reactive andesite due to the alkali-silica reaction

The Atomic-Level Structure of Cementitious Calcium Silicate Hydrate

Effects of aggregate size on alkali-silica-reaction induced expansion

Global decarbonization potential of CO2 mineralization in concrete materials

Use of X-ray diffraction to quantify amorphous supplementary cementitious materials in anhydrous and hydrated blended cements

Impact of limestone fineness on cement hydration at early age

Advances in understanding cement hydration mechanisms

Densification of C-S-H Measured by H-1 NMR Relaxometry

Reaction kinetics of dolomite and portlandite

Cement substitution by a combination of metakaolin and limestone