In today’s market, it is imperative to be knowledgeable and have an edge over the competition. ACI members have it…they are engaged, informed, and stay up to date by taking advantage of benefits that ACI membership provides them.
Read more about membership
Become an ACI Member
Founded in 1904 and headquartered in Farmington Hills, Michigan, USA, the American Concrete Institute is a leading authority and resource worldwide for the development, dissemination, and adoption of its consensus-based standards, technical resources, educational programs, and proven expertise for individuals and organizations involved in concrete design, construction, and materials, who share a commitment to pursuing the best use of concrete.
ACI World Headquarters
38800 Country Club Dr.
Farmington Hills, MI
ACI Middle East Regional Office
Sheik Rashid Tower, 7th Floor
Dubai World Trade Center
Phone: +971 4 3097066
Feedback via Email
Home > Publications > International Concrete Abstracts Portal
The International Concrete Abstracts Portal is an ACI led collaboration with leading technical organizations from within the international concrete industry and offers the most comprehensive collection of published concrete abstracts.
Title: Hydration and Carbonation of Pozzolanic Cements
Author(s): Vagelis G. Papadakis, Michael N. Fardis, and Costas G. Vayenas
Publication: Materials Journal
Appears on pages(s): 119-130
Keywords: carbonation; cements; concrete durability; concretes; corrosion; diffusion; fly ash; hydration; pore-size distribution; porosity; pozzolans; pozzolan cements; reinforcing steels; Materials Research
Abstract:Some physical and chemical characteristics of hardened cement concrete, which influence its strength and durability, are given quantitatively in terms of the chemical composition of the pozzolanic cement. The chemical reactions of pozzolanic activity and hydration are presented and used to determine the final quantity of CSH, calcium hydroxide, etc., produced per unit weight of pozzolan cement, and the minimum water-cement ratio required for hydration. Expressions are given for the final values of porosity of pozzolanic cement paste, mortar, or concrete, as affected by hydration, pozzolanic action, and carbonation, in terms of the composition of cement and of concrete or mortar mix. The effect of the pozzolans on the pore-size distribution of hardened paste is studied experimentally, and that effect on the degree of pore saturation is studied both experimentally and analytically. The effective gas diffusivity of pozzolanic cement mortar or concrete is measured, and a semi-empirical expression, developed earlier for ordinary portland cement (OPC) concrete, is fitted to the measured values. The applicability of a fundamental, yet simple, predictive model for concrete carbonation is verified experimentally, and its parameters are specified for pozzolanic cement concrete. Conclusions are drawn on the favorable or adverse effects of OPC pozzolan or aggregate pozzolan replacement on CSH-content, porosity, and rate of carbonation.
Click here to become an online Journal subscriber