INFLUENCES ON THE FIRE RESISTANCE OF CONCRETE

The addition of polypropylene fibres effectively prevents flaking of concrete sections. This limits the damage caused by the effects of a fire to a few centimetres on the surface. The choice of suitable aggregates can increase fire resistance and reduce thermal conductivity. Under these marginal conditions, tests should be carried out to determine how far modified concrete with increased fire resistance can also be used to protect structures in the general building sector. However, it should be remembered that despite all the technical precautions to increase the stability and load-bearing capacity of structures in the general building and tunnel construction sectors, security against an accident and its disastrous consequences depends on the weakest link among all the factors involved in the accident. The most important factor of all is that human beings are required to show responsible behaviour when they are using tunnel structures. Different parameters are influencing the fire resistance of concrete. The spalling of concrete can be reduced by adding polypropylene fibres. In a second step aggregates should be adopted to avoid major damages of the concrete structure. These means do not achieve any heat protection or isolation of the concrete a certain depth of the concrete will be destroyed by the time. This depth has to be taken into account when designing a project. Next to the presented protection means there are also other techniques available to protect concrete which are not a topic of this paper.

• INTRODUCTION

• DEMARCATION OF THE SUBJECT

• FIRE LOAD CURVES

• DAMAGING MECHANISM

• TEST PROCEDURES

• CONCRETE SYSTEMS

• REFERENCES