The objective of this paper is to examine the possible use of new blended cements containing calcareous fly ash in structural concrete, potentially adequate for structural elements of nuclear power plants. The investigation included five new cements made with different contents of non-clinker constituents: calcareous fly ash, siliceous fly ash, ground granulated blastfurnace slag, and a referen...

In order to avoid the potentially devastating consequences of global warming and climate change, the carbon dioxide “CO2” emissions caused due to anthropogenic activities must be reduced considerably. This paper presents the first study examining the feasibility of carbon sequestration in construction and demolition “C&D” waste. Experiments were carried out in a self fabricated Batch Reactor at...

This paper deals with a one-dimensional coupled system of semi-linear parabolic equations with a kinetic condition on the moving boundary. The latter furnishes the driving force for the moving boundary. The main results are a (global) existenceand uniqueness theorem, and non-trivial lower and upper estimates for the velocity of the moving boundary. The system under consideration is modelled on ...

Self-compacting concrete (SCC) demands more studies of durability at higher temperatures when subjected to more aggressive environments in comparison to the conventional vibrated concrete (CC). This work aims at presenting results of durability indicators of SCC and CC, having the same water/binder relations and constituents. The applied methodologies were electrical resistivity, diffusion of c...

We investigate the fast-reaction asymptotics for a one-dimensional reaction-diffusion system describing the penetration of the carbonation reaction in concrete. The technique of matchedasymptotics is used to show that the reaction-diffusion system leads to two distinct classes of sharpinterface models. These correspond to different scalings of a small parameter representing the fast-reaction an...

Mineral carbonation can be used for CO2 sequestration, but the reaction rate is slow. In order to accelerate mineral carbonation, acid generated in a microbial electrolysis desalination and chemical-production cell (MEDCC) was examined to dissolve natural minerals rich in magnesium/calcium silicates (serpentine), and the alkali generated by the same process was used to absorb CO2 and precipitat...

An innovative approach utilizing highly alkaline oil shale waste ash and carbon dioxide gas (CO2), associated with power production, as a resource for production of precipitated calcium carbonate (PCC) is introduced in this paper. The specifics and feasibility of the integrated ash valorization and CO2 sequestration process by indirect aqueous carbonation of lime-consisting ash were elaborated ...

Concrete carbonation is a process that can limit the lifetime of reinforced concrete structures. The resistance of concrete samples to carbonation is usually determined by accelerated tests under relatively high CO2-concentrations and a fixed relative humidity. No general agreement exists on whether and how the results of these experiments can be extrapolated to a natural setting. This note pre...

The oriented attachment of calcite, which is a main component of biominerals, was experimentally demonstrated in an aqueous system at ambient temperatures. Calcite nanoblocks 50 nm in size were prepared by carbonation of Ca(OH)2. One-dimensional (1D) alignment of the calcite nanoblocks was induced at ambient temperatures under a basic condition (pH 12), and single-crystalline rods over 1 mmwere...