A STRATEGY FOR MINIMISING THE EFFECTS OF PROCESS ON CONCRETE DURABILITY

Worldwide, the need to improve concrete quality and durability has long been a priority. As a result new Standards have been developed. This has involved the development of new exposure classifications with associated strength, maximum w/c ratio and minimum cement content recommendations. These are classed as “product” requirements and under ideal conditions should give high quality durable concrete, which will have the required design life for the prevailing exposure conditions.

Alas, ideal conditions are rarely present on site and every “process” problem that arises will lead to an inevitable reduction in the resistance of the concrete to aggressive elements, such as chlorides, carbonation and freeze/thaw action. This paper reviews some of the problems that arise due to “process” and how they can be partially overcome.

• INTRODUCTION

• PROCESS PROBLEMS

• EFFECT ON CONCRETE

• COMMENT

• CONTROLLED PERMEABILITY FORMWORK (CPF)

• OVERCOMING “PROCESS” PROBLEMS

• COMMENT

• CONCLUSION

• REFERENCES