As a result of useful studies carried out in the laboratories and field all over the world the pulverized fuel ash (flyash) is being utilized for manufacture of Portland pozzolana cement (PPC) and for making cement mortar and concrete. The use of PPC has accelerated with increase of awareness about its  properties in practice. The production of PPC in India in year 2002-2003 was observed to be more than 40 million tones and it is likely to cross 50 million tones this year. In India use of flyash in mortar and concrete is relatively low. Reason for it’s under utilization in mortar and concrete appears to be due to lack of confidence in the minds of user for building a permanent structure with flyash as one of the  major ingredient in concrete. This paper deals with information on required properties of good flyash as per specifications and certain experimental and practical examples on use of fly ash in various mortars and concrete mixes for various types of concrete structures in India and abroad along with         emphasis on improved properties of such flyash added concrete. These data and explanations indicate that flyash addition in mortar and concrete improves the durability along with strength.

 

Introduction

 

Use of fly ash for manufacture of PPC is increasing year by year in India . The reasons for such         increase are that new thermal power houses have started producing flyash using all modern             technologies and old ones have modified their process systems so that most of the flyash now produced are conforming to the requirements of IS 3812: 2003 (Part 1) (1), as can be seen in Table 1. Now manufacturers are also confident regarding uniform quality of flyash available from powerhouses. The use PPC is increasing because of increase in workability of mortar and concrete due to higher volume of PPC and having better technical properties in regards to durability and strength at later stages as  recommended by manufacturers and results from researchers.

 

To promote use of flyash in mortar and concrete, the author has cited certain good and proven practical examples of cement mortar made with flyash addition and their properties as achieved. A few examples of plain and reinforced concrete structures with use of flyash have also been cited. The advantages observed in old and recent concrete structures made with flyash addition have been also discussed.

 

Use of Pulverized Fuel ash (Flyash) in Cement,

Cement Mortar and Concrete (*)

N K Jain, Ex-General Manager,

National Council for Cement and Building Materials,

New Delhi, India.

 

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