This document discusses pozzolana and fly ash in concrete technology. It defines pozzolana as a finely powdered material that can be added to lime or cement mortar to increase durability by chemically reacting with calcium hydroxide. The document lists various natural and manufactured sources of pozzolanic materials including volcanic ash, calcined clay, mineral slag, and ashes of organic origin. It describes how the properties of pozzolanic materials like particle size and chemical composition affect their reactivity and the strength and setting of composites. The document also discusses how pozzolanic reactions enhance concrete properties like stiffness over time and that pozzolanic materials can improve sustainability by enabling the use of industrial and

1. MCT 6102 CONCRETE TECHNOLOGY
ASSIGNMENT
MODULE – POZZOLONA AND FLY ASH
COURSE CORDINATOR
SUBMITTED BY
DR HEMANT SOOD
ANKAJ KUMAR
ROLL NO- 202304
ME CTM ( REGULAR)

2. INTRODUCTION
A simple everyday definition of 'pozzolan' could be 'a finely powdered material which can be
added to lime mortar (or to Portland cement mortar) to increase durability. A more formal
definition is given by ASTM C618-84 as 'a siliceous or siliceous and aluminous material
which, in itself, possesses little or no cementitious value but which will, in finely divided
form in the presence of moisture, react chemically with calcium hydroxide at ordinary
temperature to form compounds possessing cementitious properties

3. SOURCES AND TYPES OF POZZOLANIC MATERIALS
 (a) Natural, very finely divided, Highly Reactive Materials of Volcanic
Origin
 (b) Low Temperature Calcined Products in Various forms
 (c) Clay or Kaolin Products specially Manufactured as Pozzolans
 (d) Mineral Slag
 (e) Ashes of Organic Origin
 (f) Certain Natural Sands and Crushed Rock Products

4.  Properties and reactivity of pozzolans and their influence on the quality of
mortars and concrete
 Industrial and agricultural waste with pozzolanic properties is used as
partial binder replacement in building materials to enhance sustainability
and improve the service life of structures. This leads to economic and
environmental benefits such as recycling waste, whose disposal threatens
the environment, and reducing cement/lime content, with the subsequent
drop in energy consumption, non-renewable raw material consumption
and CO2 emissions. Pozzolan properties including particle size, specific
surface, chemical and mineral composition, amorphousness and water
demand affect their reactivity, and consequently the setting and strength
of composites

5.  . Pozzolanic reaction is not as slow as it is generally believed; and that
hydrates are clearly present only after 24 hours of curing, forming
continuous networks throughout the paste after 14 days. It was also
evidenced that pozzolans enhance the modulus of elasticity making lime
mortars progressively stiffer however, unlike most building materials,
enhanced stiffness and larger elastic regions are not coupled to increased
brittleness, and the mortars remain plastic, undergoing significant strain
before failure even at high pozzolan contents. The work has also
evaluated and established a correlation between techniques that
measure reactivity (chemical and physical indices and portlandite
consumption) and carried out a comprehensive, comparative study of
setting times and water demand for a range of pozzolans.

17. THANK YOU