Y. Zeng
Please Note
6 records found
1
Toward FAIR and reproducible research on air lime-containing mortars
Characterization workflow and open dataset for fresh, physical, and mechanical properties
Although air lime is a carbonatable binder with high carbon sink potential, reproducible research remains hindered by the limited availability of lime-oriented standards and openly accessible datasets. These limitations prevent the consolidation of fundamental knowledge and reinforce the perception of lime mortars as highly variable and empirical materials. This study addresses this gap by implementing a FAIR-aligned (Findable, Accessible, Interoperable, Reusable) and reproducible workflow for the characterization of air lime-containing mortars. Four mixtures were monitored for up to 364 days to assess fresh, physical, and mechanical properties under defined conditions. All experimental metadata and datasets are openly published in a structured repository. Results show that air lime-containing mixtures exhibited longer setting times, higher open porosity, greater carbonation depths, and lower compressive strength. Length change measurements indicate hydration-carbonation interactions, particularly in lime-cement systems. By combining experimental characterization with a FAIR-aligned and reproducible workflow, this work supports more transparent, resource-efficient research practices.
Blast furnace slag-based alkali-activated concrete with treated municipal solid waste incineration (MSWI) bottom ash as coarse aggregate
Mechanical properties, freeze-thaw resistance, and environmental impact
Municipal solid waste incineration (MSWI) bottom ash (BA) is widely available and has been increasingly explored for sustainable concrete production. While it is commonly used in Ordinary Portland Cement (OPC)-based concrete, its application in alkali-activated concrete (AAC) remains rare. This study developed a new AAC using MSWI BA as coarse aggregate to evaluate whether this represents a more sustainable application pathway compared to its use in conventional concrete. To address issues associated with metallic aluminum (Al) in MSWI BA, a NaOH-based pre-treatment was applied to reduce its content and minimize surface cracking and volume expansion in AAC. The incorporation of treated MSWI BA increased the overall porosity of AAC. The interfacial transition zone (ITZ) surrounding MSWI BA exhibited characteristic microstructural features. While previous studies suggested that MSWI BA-induced porosity may enhance freeze-thaw resistance in OPC concrete, the opposite trend was observed in AAC. The increased pore volume, irregular pore shapes, and MSWI BA-related microcracking reduced freeze-thaw durability. Despite these challenges, the developed AAC retained mechanical performance within strength class C30/37 and achieved a substantially lower carbon footprint compared to OPC and CEM III/B concretes. Leaching assessments further confirmed that the developed AAC complied with environmental standards and did not release harmful contaminants. Overall, these findings demonstrate that MSWI BA is a promising coarse aggregate for AAC.
Adding hydrated lime (CH) into blended cement incorporating high volume of Supplementary Cementitious Materials (SCMs) is a viable method to provide the necessary calcium hydroxide for the pozzolanic reaction, thereby improving the mechanical performance at later stages. However, the effects of relatively small dosages of CH on the rheological properties and resulting microstructure of limestone-calcined clay cement (LC3) remain unclear. This paper aims to investigate the influence of a small CH addition on the fresh and hardened properties of LC3 systems, in which Portland cement is largely replaced (80 wt%) by limestone and calcined clay. The results indicate that the additional CH notably reduces the water film thickness, leading to increased dynamic yield stress, plastic viscosity and re-flocculation. A delay in the elasticity development and static yield stress evolution within the first 1.5 h was observed with the addition of 2.5 wt% CH, attributed to the initial dissolution of CH, which is mitigated by using 10 wt% CH. Furthermore, additional CH accelerated early-age hydration and facilitated long-term pozzolanic reactions, resulting in the increased amount of C-(A)-S-H gel and AFm phases, and reduced porosities after 7 and 28 days. These chemical effects could well compensate the high air void content caused by the high viscosity, and therefore contributes to mortars with higher compressive strengths than plain LC3 at later ages.
Carbonation depth of lime-based binders
Current measurement methods and limitations