An integrated framework of coastal flood modelling under the failures of sea dikes: a case study in Shanghai

Climate change leads to sea level rise worldwide, as well as increases in the intensity and frequency of tropical cyclones (TCs). Storm surge induced by TC’s, together with spring tides, threatens to cause failure of flood defenses, resulting in massive flooding in low-lying coastal areas. However, limited research has been done on the...

Mechanisms of autogenous shrinkage of alkali-activated slag and fly ash pastes

This study aims to provide a better understanding of the autogenous shrinkage of slag and fly ash-based alkali-activated materials (AAMs) cured at ambient temperature. The main reaction products in AAMs pastes are C-A-S-H type gel and the reaction rate decreases when slag is partially replaced by fly ash. Due to the chemical shrinkage and the...

Internal curing by superabsorbent polymers in alkali-activated slag

In this study, internal curing by superabsorbent polymers (SAP) is utilized to mitigate self-desiccation and autogenous shrinkage of alkali-activated slag (AAS) pastes. Absorption and desorption kinetics of SAP incorporated in AAS pastes were studied with X-ray tomography. Internal curing delayed the peak of the rate of heat liberation but...

Numerical Study on Chloride Ingress in Cement-Based Coating Systems and Service Life Assessment

Chloride-induced corrosion is a critical issue for RC structures. Cement-based coatings can be used to protect concrete structures with unsatisfactory quality against chloride ingress. To evaluate the effectiveness of the coatings to extend the service life of coated concrete structures, the evolution of the chloride profile in the coated...

Simulation of moisture transport in hydrating cement-based overlay systems

Drying of cement-based overlay systems is a critical issue, because it causes differential shrinkage between the overlay material and the concrete substrate and may induce cracking or debonding of the overlay material. In this paper the mechanisms of moisture transport in hydrating cement-based overlay systems are studied. A model is proposed...

Relationship between the size of the samples and the interpretation of the mercury intrusion results of an artificial sandstone

Mercury intrusion porosimetry (MIP) measurements are widely used to determine pore throat size distribution (PSD) curves of porous materials. The pore throat size of porous materials has been used to estimate their compressive strength and air permeability. However, the effect of sample size on the determined PSD curves is often overlooked....

Characterization and comparison of capillary pore structures of digital cement pastes

More and more studies are based on digital microstructures of cement pastes obtained either by numerical modelling or by experiments. A comprehensive understanding of the their pore structures, therefore, becomes significant. In this study, the pore structure of a virtual cement paste (HYMO-1d) generated by cement hydration model HYMOSTRUC 3D...

Micromechanical study of the interface properties in concrete repair systems