Experimental and numerical study on the mitigation of autogenous shrinkage of cementitious material

This study experimentally investigated the effects of surfactants and water-repelling agents on the hydration process, relative humidity, and mechanical properties of Portland cement pastes. Based on the measurement results, the degree of hydration, degree of saturation, capillary tension of autogenous shrinkage, and magnitude of autogenous...

The effect of sulfate-rich sewage sludge ash on the volume deformation and micorstructure of cement paste

Sewage sludge ash (SSA) is the combustion residue of the sewage sludge obtained from wastewater treatment plants. In China, SSA normally contains high content of SO3, which may cause detrimental effect on the volume stability of cement-based materials. This study investigated the effect of sulfate-rich SSA (SR-SSA) on the volume deformation and...

Drying shrinkage of alkali-activated slag and fly ash concrete; A comparative study with ordinary Portland cement concrete

This study investigates the drying shrinkage and the shrinkage-induced stress of alkali-activated blast furnace slag and fly ash concrete (AC) in comparison with ordinary Portland cement concrete (OC). For samples that were dried from 1 day after casting, the drying shrinkage of AC was much higher than that of OC. For samples that were stored...

Intriguing luminescence properties of (Ba, Sr)₃Si₆O₉N₄: Eu²⁺ phosphors via modifying synthesis method and cation substitution

Synthesizing pure phase Ba₃Si₆O₉N₄ by the conventional solid-state reaction method is challenging because of easily formed secondary phase Ba₃Si₆O₁₂N₂ showing similar crystal structure. In this work, an alternative low temperature synthesis method is...

Viscoelastic stress modeling in cementitious materials using constant viscoelastic hydration modulus

Viscoelastic stress modeling in ageing cementitious materials is of major importance in high performance concrete of low water cement ratio (e.g. w/c ~0.35) where crack resistance due to deformation restraint needs to be determined. Total stress analysis is complicated by the occurrence of internal stresses due to shrinkage, which requires...