Is fly ash the same as slag?

Is fly ash the same as slag?

Although set times are prolonged with fly ash, in just 28 days, the strength of the concrete will surpass the same mix without the fly ash. Slag is similar to fly ash in that it is finer than standard Portland cement and is also cheaper as it is a process byproduct. Slag is produced by the steel production industry.

What does adding fly ash do to concrete?

Fly ash use in concrete improves the workability of plastic concrete, and the strength and durability of hardened concrete. When fly ash is added to concrete, the amount of portland cement may be reduced.

Is fly ash bad for concrete?

Poor-quality fly ash can have a negative effect on concrete. The principle advantage of fly ash is reduced permeability at a low cost, but fly ash of poor quality can actually increase permeability. Some fly ash, such as that produced in a power plant, is compatible with concrete.

Which is better, fly ash based or slag cement?

Flyash cement increases the workability of concrete as that of slag based, and slag based concrete increases the compressive strength of concrete as compared to that with flyash based concrete when used in appropri FlyAsh based cement and Slag based cement concrete both have marked a crucial part in concrete industry.

What kind of slag is used for cement?

Low-calcium (FA) and high-calcium (HCFA) fly ash and granulated blast furnace slag (GBFS) are the most widely known, standardized and used SCMs in the composition of cement and concrete.

Which is cheaper, Portland cement or fly ash?

Fly ash and Slag will typically be 18% cheaper than Portland cement. When a mix includes 20% fly ash, this will provide savings of 3.5% in cost. The advantage of slag is its ability to substitute more of cement.

When did they start using fly ash in concrete?

By: Michael Thomas, Ph.D., P.Eng., Professor of Civil Engineering, University of New Brunswick Figure 1. Fly ash, a powder resembling cement, has been used in concrete since the 1930s. (IMG12190) Table 1. Dosage Levels of Fly Ash Level of Fly Ash Classification % by mass of total cementitious material