ABSTRACT
Shotcrete is commonly used in Swedish tunnels. In this paper the author will discuss problems with curing, bond, residual strength. fibre content, spraying, quality control and testing, that have been encountered over the last 25 years. Some additional problems that have been observed include the following. Improper curing can cause detrimental cracking of a shotcrete lining. Poor cleaning can cause low bond strength between the shotcrete and rock. Poor control of the fibre content can cause low residual strengths. Optimistic spraying under difficult conditions might also lead to porous concrete. Quality control systems sometimes exist only in theory. The relevance of tests as performed is difficult to judge. These mistakes are costly and unnecessary since education and discipline can help to avoid most of them.
