What is the ASTM test that defines fly ash?
ASTM C618 defines two classes of fly ash for use in concrete: 1) Class F, usually derived from the burning of anthracite or bituminous coal, and 2) Class C, usually derived from the burning of lignite or subbituminous coal.
Which class fly ash is used for in concrete?
Class F fly ash was used as a partial replacement of binder in concrete. The concrete mixtures conducted in a controlled environment and lime saturated water was used for wet curing and ambient temperature for air curing.
What is the class C in fly ash concrete?
High calcium fly ash (Class C) acts as a good source of calcium hydroxide which “self activates”, reacting with silica and alumina in the fly ash and soil to form a cementitious hydration product. In addition, C3A in fly ash (Class C) can react with sulfates to gain strength relatively quickly.
What is ASTM c94?
ASTM C 94 “Standard Specifica- tion. for Ready Mixed Concrete” is the specification almost uni- versally used in the United States for concrete manufactured and deliv- ered to a purchaser in a freshly mixed and unhardened state.
What are the different classes of fly ash?
Two classes of fly ash are defined by American Society for Testing and Materials (ASTM) C618: Class F fly ash and Class C fly ash. The chief difference between these classes is the amount of calcium, silica, alumina, and iron content in the ash.
What is ASTM C595?
ASTM C595. This specification pertains to blended hydraulic cements for both general and special applications, using slag or pozzolan, or both, with portland cement or portland cement clinker or slag with lime.
Is code slag a cement?
It is manufactured either by intimately intergrinding a mixture of Portland cement clinker and granulated slag with addition of gypsum or calcium sulphate, or by an intimate and uniform blending of Portland cement and finely ground granulated slag.
What is class F flyash?
Class F fly ash is designated in ASTM C 618 and originates from anthracite and. bituminous coals. It consists mainly of alumina and silica and has a higher LOI than. Class C fly ash. Class F fly ash also has a lower calcium content than Class C fly ash.
What is fly ash Class 11?
What is fly ash? It is a waste product from the steel industry and has properties similar to that of cement. It mainly consists of calcium silicate.
Why is Class F fly ash better than C?
Application of Fly Ash in Construction Class C provides concrete strength in the early stages of construction while Class F provides strength and lessens permeability in the long run. Due to its higher silica content, Class F fly ash is considered to be more effective compared to Class C fly ash.
What is Class C fly ash used for?
Class C fly ash for use in Portland cement concrete in pavements.
What is the performance of fly ash in concrete?
The performance of fly ash in concrete is strongly influenced by its physical, mineralogical and chemical properties.The mineralogical and chemical composition are dependent to a large extent on the composition of the coal and since a wide range of domestic and imported coals (anthracite, bituminous, sub-bituminous and lignite)
What is the level of fly ash classification?
(IMG12190) Table 1. Dosage Levels of Fly Ash Level of Fly Ash Classification % by mass of total cementitious material <15 Low 15-30 Moderate 30-50 High >50 Very High 2 The Nature of Fly Ash Fly ash is a by-product of burning pulverized coal in an electrical generating station.
What is the ASTM C618 standard for fly ash?
The most widely used specification for fly ash in North America is ASTM C618 Standard Specification for Coal Fly Ash and Raw or Calcined Natural Pozzolan for Use in Concrete (AASHTO M 295). This specification divides fly ash into two classes based on its source of origin and composition as described in Table 2.
Can I use Class C fly ash with Type F cement?
Do not use Class C fly ash. A dosage level of 20 to 30% Class F fly ash will generally Test cement—fly ash combinations using ASTM C1012. provide equivalent performance to a Type II or V portland Consider using Class F fly ash with sulfate- cement (ASTM C150) cement or a Type MS or HS hydraulic resisting portland cement. cement (ASTM C1157).