Environmental, economic and engineering performances of aqueous carbonated steel slag powders as alternative material in cement pastes: Influence of particle size.

The low reactivity and volume expansion issue of steel slag limits its application as alternative to cement. Studies demonstrated that aqueous carbonation (AC) can enhance the cementitious properties of finely sized steel slag as a cementitious supplementary material (SCM). However, the impact of particle size on the CO uptake capacity and its association of performance of carbonated steel slag remains unexplored.

Report of RILEM TC 281-CCC: outcomes of a round robin on the resistance to accelerated carbonation of Portland, Portland-fly ash and blast-furnace blended cements.

Unlabelled: Many (inter)national standards exist to evaluate the resistance of mortar and concrete to carbonation. When a carbonation coefficient is used for performance comparison of mixtures or service life prediction, the applied boundary conditions during curing, preconditioning and carbonation play a crucial role, specifically when using latent hydraulic or pozzolanic supplementary cementitious materials (SCMs). An extensive interlaboratory test (ILT) with twenty two participating laboratories was set up in the framework of RILEM TC 281-CCC 'Carbonation of Concrete with SCMs'.

Upcycling of wastes for sustainable controlled low-strength material: A review on strength and excavatability.

In recent decades, the use of controlled low-strength material (CLSM) in densely populated cities has increased. CLSM is designed for future excavation with great fluidity, appropriate early strength, and low final strength. CLSM mixtures exhibit variable strength properties and performance due to the distinctive features of wastes (i.

CO pretreatment of municipal solid waste incineration fly ash and its feasible use as supplementary cementitious material.

In this study, municipal solid waste incineration fly ash (MSWIFA) was pretreated with CO via slurry carbonation (SC) and dry carbonation coupled with subsequent water washing (DCW). Both the treated MSWIFAs were then used as cement replacement in cement pastes by weight of 10%, 20% and 30% to investigate the influence on hydration mechanisms, physico-mechanical characteristics and leaching properties. The results showed that carbonates formed on the surface of SC-MSWIFA particles were finer (primarily 20-50 nm calcite) than those from the corresponding DCW-MSWIFA (mostly 130-200 nm vaterite).

Environmental benefit assessment of steel slag utilization and carbonation: A systematic review.

The rapid increase in steel slag generation globally highlights the urgent need to manage the disposal or utilization processes. In addition to conventional landfill disposal, researchers have successfully reused steel slag in the construction, chemical, and agricultural fields. With the large portions of alkaline silicate mineral content, steel slag can also be used as a suitable material for carbon capture to mitigate global warming.

Roles of chlorine and sulphate in MSWIFA in GGBFS binder: Hydration, mechanical properties and stabilization considerations.

In this study, municipal solid waste incineration fly ash (MSWIFA) was first washed (pretreatment) with pure water with liquid to solid (L/S) ratio of 2, 3, 6, 10, to understand the removal efficiency of chlorine and sulphate, as well as its consequent ability as alkaline activator for granulated blast furnace slag (GGBFS). Washed MSWIFA was blended with GGBFS at a fixed ratio of 3:7 to examine their impact on mechanical properties, reaction mechanism, microstructure and leaching behavior. The results showed that chlorine in MSWIFA (>70%) can be washed out easily, while the removal of sulphate was largely depended on the L/S.

Effect of water-to-cement ratio induced hydration on the accelerated carbonation of cement pastes.

Recently, the use of accelerated carbonation curing has attracted wide attention as a promising method to reduce carbon dioxide (CO) emission and improve the mechanical properties of cement-based materials. However, the diffusion mechanism of CO in the matrix and the content of hydration products are the key factors that restrict the carbonation reaction rate. To understand the combined behavior of hydration and carbonation reactions, this paper investigates the influence of cement hydration induced by water-to-cement ratio (w/c) (ranging from 0.

Highly-efficient green photocatalytic cementitious materials with robust weathering resistance: From laboratory to application.

The combined use of nano-TiO with cementitious materials offers an environmentally-friendly way to combat the air pollution problem. However, a trade-off between a high efficiency and a robust weathering resistance has often to be made for most of the attempted nano-TiO incorporation methods. This paper developed a simple and effective "spraying" method to coat nano-TiO particles on the surface of concrete surface layers (CSL).

A critical review of waste glass powder - Multiple roles of utilization in cement-based materials and construction products.

In light of concerns relating to improper waste disposal and resources preservation, reclamation of the discarded glass in construction materials had been extensively carried out since 1963. In the past decade, although more than 100 papers associated with the use of glass powder (GP) in the micron level scale were published, comprehensive review of all practical applications in cement-based materials and construction products is not available. This paper therefore provides a summary of the body of knowledge on the interaction and effects of using GP in cement-based and extended construction materials.

Waste resources recycling in controlled low-strength material (CLSM): A critical review on plastic properties.

The exponential growth of waste generation is posing serious environmental issues and thus requires urgent management and recycling action to achieve green sustainable development. Controlled low-strength material (CLSM) is a highly flowable cementitious backfill material with self-consolidating properties. The CLSM efficiency during construction and final performance at the site depends on its plastic properties.

Enhancement of high temperature performance of cement blocks via CO curing.

Carbonation for the curing of cement-based materials has been gaining increased attention in recent years, especially in light of emerging initiatives to reduce carbon dioxide (CO) emissions. Carbonation method or CO curing is founded on the basis of the reaction between CO and cement products to form thermally stable and denser carbonate, which not only improves the physical and mechanical properties of cement-based materials, but also has the ability to utilize and store CO safely and permanently. This study aims to assess the effect of CO curing technology on the high-temperatures performance of cement blocks.

Properties of Foamed Mortar Prepared with Granulated Blast-Furnace Slag.

Foamed mortar with a density of 1300 kg/m³ was prepared. In the initial laboratory trials, water-to-cement (w/c) ratios ranging from 0.54 to 0.

Development of a method for recycling of CRT funnel glass.

Finding better solutions to manage and recycle cathode-ray tube (CRT) glass is crucial for reducing the environmental threats due to the disposal of the glass. In this paper, the results of a laboratory study on developing a method for removing lead from crushed funnel glass surface and re-utilizing the treated glass in cement mortar are presented. The results demonstrate that nitric acid at 3-5% concentration levels can be used to remove most of the lead from the crushed funnel glass surface and render it as non-hazardous waste based on toxicity characteristics leaching procedure (TCLP) testing.

Utilization of recycled cathode ray tubes glass in cement mortar for X-ray radiation-shielding applications.

Recycled glass derived from cathode ray tubes (CRT) glass with a specific gravity of approximately 3.0 g/cm(3) can be potentially suitable to be used as fine aggregate for preparing cement mortars for X-ray radiation-shielding applications. In this work, the effects of using crushed glass derived from crushed CRT funnel glass (both acid washed and unwashed) and crushed ordinary beverage container glass at different replacement levels (0%, 25%, 50%, 75% and 100% by volume) of sand on the mechanical properties (strength and density) and radiation-shielding performance of the cement-sand mortars were studied.

Utilization of recycled glass derived from cathode ray tube glass as fine aggregate in cement mortar.

Rapid advances in the electronic industry led to an excessive amount of early disposal of older electronic devices such as computer monitors and old televisions (TV) before the end of their useful life. The management of cathode ray tubes (CRT), which have been a key component in computer monitors and TV sets, has become a major environmental problem worldwide. Therefore, there is a pressing need to develop sustainable alternative methods to manage hazardous CRT glass waste.

Use of wastes derived from earthquakes for the production of concrete masonry partition wall blocks.

Utilization of construction and demolition (C&D) wastes as recycled aggregates in the production of concrete and concrete products have attracted much attention in recent years. However, the presence of large quantities of crushed clay brick in some the C&D waste streams (e.g.