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...

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...

A consolidating product based on nanoparticles of slaked lime (Ca(OH)2) dispersed in isopropyl alcohol was exposed under different relative humidities (RH), 33%, 54%, 75% and 90% during 7, 14, 21 and 28 days. The characterization of the calcium hydroxide nanoparticles and the formed calcium carbonate polymorphs has been performed by Micro-Raman spectroscopy, Transmission Electron Microscopy (TE...

The aim of this study is to examine the effect replacing waste aluminum sawdust (AS) with fine aggregate on strength and durability properties concrete. For this, concrete mixtures a cement dosage 400 kg/m3 water/cement (W/C) ratio 0.40-0.50-0.60 were prepared. AS obtained from Elazig industrial site was added by 0%, 0.5% 1% volume. After curing in pool for 28 days, produced samples subjected a...

Construction sludge frequently has high alkalinity after its generation or during the intermediate treatment process. The aim of this study is to experimentally investigate potential combining accelerated carbonation and a paper ash-based stabilizer (PSAS) neutralize construction in short period improve strength for use as recycled material. experimental results indicate that addition PSAS sign...