fib Bulletin No. 41 – Treatment of Imperfections in Precast Structural Elements






1 Introduction

Imperfections in concrete structures are impossible to avoid and the personnel involved in

construction should know how to deal with them. Imperfections can range from minor surface blemishes to major structural defects.

Because many imperfections are at the limits of specified quality deviations, or are not included in the acceptance criteria, the problem is more complicated than a decision between rejection or acceptance.

Precast concrete structural members, reinforced or prestressed, are widely used and often a preferred solution in the construction industry. The proven strength, quality and performance characteristics of precast concrete members make them ideal for wide a variety of civil engineering and construction applications. In addition to this and their inherent fire resistance, they offer many advantages over other materials by way of speed of erection and the creation of an immediate working platform.

Precast concrete, structural and architectural members are usually manufactured by skilled labour in a controlled environment and are renowned for their high quality. However there are occasions when the quality of the manufactured product is not what is intended in the design. This can be due to many causes such as weather effects, quality of constituent materials, handling and erection.

This document describes the most common types of imperfections encountered during manufacture, stacking, transport and erection and suggests a number of possible remedial actions. The remedial actions depend on the severity of the imperfection, the feasibility of repair and the consequences on the intended use of the concrete member.



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