Prediction of the chemical shrinkage of Portland cement

Chemical shrinkage is one of the main reasons leading to the early age deformation of concrete. Hence, the prediction of chemical shrinkage is an important issue for evaluating the deformation of concrete and its influence on the durability of concrete structures. There is still room to improve the accuracy for predicting the chemical shrinkage...

Incorporating elastic and creep deformations in modelling the three-dimensional autogenous shrinkage of cement paste

A structure-based modelling framework was established to simulate the three-dimensional autogenous shrinkage of cement paste. A cement hydration model, HYMOSTRUC3D-E, was used to obtain the microstructures and ionic concentrations of the cement paste. A lattice fracture model based on the effective stress and effective modulus was used to...

Effect of coarse aggregate size on non-uniform stress/strain and drying-induced microcracking in concrete

Non-uniform stresses, strains and microcracking of the concretes with three coarse aggregate sizes (5–10 mm, 10–16 mm, 16–20 mm) dried under 40% relative humidity (RH) for 60 days were quantified using digital image correlation and lattice fracture modelling. The influencing mechanism of coarse aggregate size on the drying-induced...

Reactions of self-healing agents and the chemical binding of aggressive ions in sea water: Thermodynamics and kinetics

New self-healing agents that can chemically bind seawater ions invading cracked cementitious materials were proposed. The potential of self-healing and binding of seawater ions were investigated by thermodynamic modeling. It was found that CaO-NaAlO₂ and CaO-metakaolin agents can have Cl⁻, SO₄²⁻ and...

Simulation of Poyang Lake water levels and outflow under historical extreme hydrological scenarios

Due to an intensification of anthropogenic activities and climate change in recent decades, the hydrological connections and relationships between rivers and lakes have been significantly modified globally. Poyang Lake is one of the largest freshwater lakes globally and is one of the few that remain naturally connected to the Yangtze River....

Unveiling the inequalities in virtual water transfer in China: The environmental and economic perspectives

To alleviate the geographical mismatch between supply and demand of water resources, virtual water trade had attracted extensive attention. Many studies had estimated the virtual water flow and measured the virtual water inequality using Environmental Input-Output (EIO) model. However, EIO model ignores the feedback effect in the trade, which...

Evaluation of RRSB distribution and lognormal distribution for describing the particle size distribution of graded cementitious materials

Graded blended cement made of graded Portland cement (PC), blast furnace slag (BFS) and fly ash (FA) is attractive for cement production. For manufacturing graded blended cement, a suitable mathematical expression should be introduced to describe the particle size distribution (PSD) of its components and control the quality of graded blended...

Influence of surface pretreatment on phosphate conversion coating on AZ91 Mg alloy

Surface pretreatment is generally applied before application of protective coatings on Mg alloys, which influences surface microstructure and electrochemical activity of the substrate and has an effect on the coating properties. The effect of various pretreatment processes (sand-blasting, grinding and polishing) on the microstructure and...

Investigation of drying-induced non-uniform deformation, stress, and micro-crack propagation in concrete

Concrete generally deforms and cracks in a non-uniform manner under drying-induced stress. This study used the lattice fracture model to simulate the drying-induced non-uniform deformations, stresses, and micro-crack propagation in concrete. Experiments were designed to validate the lattice fracture model, wherein the drying-induced non...

Effect of relative humidity on drying-induced damage in concrete: A comparative study of digital image correlation and lattice modelling

To assess the effect of relative humidity (RH) on drying-induced damage in concrete, the non-uniform strains and microcracks in concrete under different RH conditions were obtained using the digital image correlation (DIC) technique and lattice fracture model. The simulated non-uniform displacements were consistent with those captured using...

Extension of the Hymostruc3D model for simulation of hydration and microstructure development of blended cements

The HYMOSTRUC3D model has been used successfully to predict hydration and microstructure development of pure Portland cement paste. In recent years, a number of numerical models were proposed for optimizing the use of supplementary cementitious materials. Also HYMOSTRUC3D was extended for simulating the hydration and microstructure development...

Nanoprobes for PET/MR Imaging

The development of clinical imaging techniques significantly improves diagnostic accuracy and provides guidance for personalized treatment of individuals. However, every single imaging modality has its distinct drawbacks that cannot fully fulfil the diagnosis requirement. Thus, rational combination of different imaging modalities can achieve...