Corrosion of Embedded Metals in Concrete

Corrosion of Embedded Metals in Concrete Corrosion of reinforcing steel and other embedded metals is the leading cause of deterioration in concrete. When steel corrodes, the resulting rust occupies a greater volume than the steel. This expansion creates tensile stresses in the concrete, which can eventually cause cracking, delamination, and spalling (Figs. 1 and 2). …

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Origin and Classification of Aggregates

Origin and Classification of Aggregates Most of the properties of an aggregate derive from its parental rock chemical and mineral composition which affects strength, stiffness, density, pore structure and permeability. Rocks experience geothermal and weathering processes which can produce granular materials in the form of natural gravels and sands, these types of aggregates can be …

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Pervious Concrete

Pervious Concrete Pervious concrete is a type of concrete with a system of interconnected pores allowing water to rapidly drain through. Pervious concrete itself is made up of coarse aggregate that is coated by a thin layer of cement paste, holding the system together. While the compressive strength, void content, and permeability tend to vary …

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Characteristics of High volume Fly Ash Concrete

fly ash

Flyash Flyash is the by-product of the combustion of pulverized coal and is collected by mechanical and electrostatic separators from the fuel gases of power plants where coal is used as a fuel and the disposal of flyash is one of the major issues for environmentalists as dumping of flyash as a waste material may …

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Types of Chemical Admixtures

admixtures

Admixtures A material other than water, aggregates, or cement that is used as an ingredient of concrete or mortar to control setting and early hardening, workability, or to provide additional cementing properties. Why is admixture used? Over decades, attempts have been made to obtain concrete with certain desired characteristics such as high compressive strength, high …

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Information for Ordering Concrete

Concrete pump

Information for Ordering Concrete When ordering pre-mixed concrete, you will need to tell the supplier: Name and address for delivery The use of the concrete (i.e. driveway, housing slab, commercial) The amount you need in cubic metres The Class of the concrete. There are two classes that concrete can be supplied as: Normal Class and Special …

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Carbonation and Corrosion

Carbonation and Corrosion

Carbonation is the term used to describe the effect of carbon dioxide on a material. The phenomenon rarely leads to structural problems but carbonation-induced corrosion can lead to unsightly spalling on structures. The repair costs, for example to multi-storey office development façades, can be considerable. Carbonation of cementitious materials results in a lowering of the …

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Concrete Aggregates: Effects and Classification

concrete aggregate

Aggregates: Effects and Classification Aggregates constitute a skeleton of concrete. Approximately three-quarters of the volume of conventional concrete is occupied by aggregate. It is inevitable that a constituent occupying such a large percentage of the mass should contribute important properties to both the fresh and hardened product. Aggregate is usually viewed as an inert dispersion …

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