Journal ArticleDOI
Physical and Chemical Characteristics Affecting the Durability of Concrete
TLDR
In this paper, the molar concentration of those constituents that are susceptible to carbonation, porosity and pre-size distribution, degree of saturation of the pores, and effective diffusivity of gases through the concrete are determined analytically and/or experimentally in terms of the composition parameters and environmental condtions.Abstract:
The durability of reinforced concrete is influenced by those physical characteristics of concrete that control the diffusion of gases, such as CO2 and O2 or of liquids (mainly water) through its pores, and the diffusion of ions, such as Cl-, dissolved in the pore water. These physical characteristics depend on the composition of concrete, the chemical composition and type of cement, and the relative humidity and temperature of the environment. In the present paper, these characteristics of concrete are determined analytically and/or experimentally in terms of the composition parameters and environmental condtions; the molar concentration of those constituents that are susceptible to carbonation; the porosity and pre-size distribution; the degree of saturation of the pores; and effective diffusivity of gases through the concrete.read more
Citations
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Journal Article
Corrosion of steel by concrete
TL;DR: In this paper, the authors examined the reactions of various concretes on steel reinforcement and concluded that the most significant influences on the corrosion of prestressing wire in concrete are: the presence of chloride, presence of nitrates, the composition of concrete, the degree of carbonation of the concrete; concrete compaction and chlorides and sulphates should be used as far as possible when steel is embedded.
Journal ArticleDOI
Effect of supplementary cementing materials on concrete resistance against carbonation and chloride ingress
TL;DR: In this paper, the durability of Portland cement systems incorporating supplementary cementing materials (SCM; silica fume, low and high-calcium fly ash) is investigated.
Journal ArticleDOI
Investigation of the carbonation mechanism of \{CH\} and C-S-H in terms of kinetics, microstructure changes and moisture properties
TL;DR: In this paper, the carbonation mechanism of CH and C-S-H within type-I cement-based materials in terms of kinetics, microstructure changes and water released from hydrates during carbonation was investigated.
Journal ArticleDOI
Fundamental modeling and experimental investigation of concrete carbonation
TL;DR: In this paper, the physicochemical processes in concrete carbonation are presented and modeled mathematically, including the diffusion of CO2, in the gas phase of concrete pores, its dissolution in the aqueous film of these pores, the dissolution of solid Ca(OH)2 in the water of the the pore, its ultimate reaction with the dissolved CO 2, and the reaction of CO 2 with CSH and with the yet unhydrated C3S and C2S.
Journal ArticleDOI
Measurement methods of carbonation profiles in concrete: Thermogravimetry, chemical analysis and gammadensimetry
TL;DR: In this paper, the authors deal with two experimental methods to determine carbonation profiles in concrete: Gammadensimetry is a non-destructive test method able to measure the total penetrated CO2 and to monitor the carbonation process during laboratory accelerated tests, and TGA-CA gives accurate quantitative profiles in carbonated cementitious materials.
References
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Book
The chemistry of cement and concrete
TL;DR: The chemistry of cement and concrete as discussed by the authors, The chemistry of concrete and its properties, and the relationship between concrete and cement, is a classic example of such an approach. But it is not suitable for outdoor use.
Journal ArticleDOI
Diffusion in catalyst pellets
N. Wakao,J. M. Smith +1 more
TL;DR: In this paper, a theory for predicting diffusion rates at constant pressure through bi-disperse porous media is proposed, where the total rate is the sum of separate contributions for diffusion through macropores, micropores and a series path.
Journal Article
Corrosion of steel by concrete
TL;DR: In this paper, the authors examined the reactions of various concretes on steel reinforcement and concluded that the most significant influences on the corrosion of prestressing wire in concrete are: the presence of chloride, presence of nitrates, the composition of concrete, the degree of carbonation of the concrete; concrete compaction and chlorides and sulphates should be used as far as possible when steel is embedded.
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