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 …
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 …
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 …
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 …
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 …
Rodded Unit Weight of Coarse Aggregates PURPOSE Determination of the unit weight of coarse aggregates in a compacted condition. This test method is applicable to aggregates not exceeding 15 cm in nominal size. The unit weight so determined is necessary for the design of a concrete mixture by the absolute value methodز EQUIPMENT AND MATERIALS …
Concrete in Compression It is generally accepted that the behavior of a reinforced concrete member under load depends on the stress–strain relationship of the materials, as well as the type of stress to which it is subjected. With concrete used principally in compression, the compressive stress–strain curve is of primary interest. The compressive strength of concrete …
Concrete in Tension: Tensile Strength of Concrete The tensile and compressive strengths of concrete are not proportional, and an increase in compressive strength is accompanied by an appreciably smaller percentage increase in tensile strength. According to the ACI Code Commentary, the tensile strength of normal-weight concrete in flexure is about 10% to 15% of the …