YZ

Y. Zhang

30 records found

Due to the gradual diffusion of CO2 under natural exposure, areas with varied degrees of carbonation exist at different depths from the surface of slag-rich cement paste. While extensive research has been dedicated to investigating the fully carbonated zone as identifi ...
Carbonation of alkali-activated slag (AAS) materials has been primarily concerned in atmospheres with gaseous CO2. This study, by contrast, highlights that AAS pastes would also be carbonated under tap water immersion. Calcite is the main CO2-bear phase in b ...
Recycling aluminosilicate-based solid wastes is imperative to realize the sustainable development of constructions. By using alkali activation technology, aluminosilicate-based solid wastes, such as furnace slag, fly ash, red mud, and most of the bio-ashes, can be turned into alt ...
In this paper, the authors characterized two types of zonation within slag rims in aged alkali-activated slag (AAS) systems through SEM and TEM technology. These two elemental zonation were closely related to the pore structure of AAS pastes, thus providing strong implication for ...
Limestone-calcined clay-cement (LC3), as one of the most promising sustainable cements, has been under development over the past decade. However, many uncertainties remain regarding its rheological behaviors, such as the metakaolin content of calcined clay. This study aims to inv ...
To understand the influence of slag chemistry on the carbonation resistance of slag-rich cement, this paper explored the carbonation characteristics of blended cement systems with different Al2O3 contents in slag through accelerated carbonation test. Irrespe ...
Formulation of quaternary blended system containing ordinary Portland cement or clinker, slag, limestone and calcined clay (LC2) appeared to be a viable approach to developing low-clinker cements without severely sacrificing mechanical performance at later ages. This paper invest ...
This study aims to experimentally investigate the autogenous deformation and the stress evolution in restrained high-volume ground granulated blast furnace slag (GGBFS) concrete. The Temperature Stress Testing Machine (TSTM) and Autogenous Deformation Testing Machine (ADTM) were ...
Autogenous shrinkage may be a critical issue concerning the use of limestone-calcined clay-cement (LC3) in high-performance concrete and 3D printable cementitious materials, which have relatively low water to binder (W/B) ratio. Adding an internal curing agent, i.e., superabsorbe ...
This paper presents the influence of P2O5 incorporated in slag on the hydration characteristics of cement-slag system. It was found that the gradual addition of phosphorus oxide in slag did not change overall mineralogy of the hydration products. Except hydr ...
This study investigated the evolution process of high-volume slag cement (HVSC) paste from a chemo-mechanical standpoint. HVSC specimens with a 70 w.t. % slag replacement rate were studied at various ages. Evolution of phase assemblage, microstructure development, and micromechan ...
Additively manufactured vascular networks have great potential for use in autonomous self-healing of cementitious composites as they potentially allow multiple healing events to take place. However, the existence of a vascular tube wall may impede with the healing efficiency if i ...
For a better understanding of the hydrotalcite-like phase with SEM-EDS microanalysis, the present research paid special attention to the data acquisition and interpretation of this technique. A lower Mg/Al ratio was obtained when using a higher accelerating voltage, and a beam en ...
Through the integration of SEM-BSE and TEM, we gained a comprehensive 3-dimensional understanding of different distribution patterns of inner hydration products of slag. For fully hydrated small slag grains, two distinct sub-zones were formed in the rims. Lath-like, well-crystall ...
In 3D concrete printing, fast structuration is a prerequisite for ideal buildability. This paper aims to study the impact of inorganic additives, i.e., CaCl2 and gypsum, on structural build-up and very early-age hydration of limestone-calcined clay-cement (LC3) pastes ...
This paper identified carbonation products in the slag-rich cementitious systems upon three different exposure conditions, namely, long term exposure in the field, indoor natural exposure, and accelerated carbonation testing. Overall, mineralogy of the carbonation products was fo ...
Because the essential quality metrics of blast furnace slag are based on its oxide composition, the determination of chemical compositions of unhydrated slag grains in an aged concrete could be useful for understanding its past performance and in predicting the remaining service ...
This paper reports the carbonation characteristics of a cement-slag system exposed to accelerated carbonation testing, and its improved carbonation resistance with the increasing MgO content in blast furnace slag, in which hydrotalcite-like phase plays a key role. Our research sh ...
In order to compensate the limited availability of raw material resources and meet the growing demand for decreasing CO2 emissions during cement and concrete productions, a practical method is to decrease the clinker content in cement. This strategy mainly consists of substitutin ...
This paper studies chemical composition of partially and fully hydrated slag grains in a (nearly) 40-year-old field concrete from the Netherlands. The concrete samples were assumed to be sufficiently aged to contain fully hydrated slag grains as well as partially hydrated large s ...