Workshop on Performance-based Specifications for Concrete

Recent advances in cementitious material and chemical admixture technology, as well as the growing use of recycled materials have supported the increasing use of modern types of concrete that are not covered in existing codes and specifications and which are tailor- made for a specific application or project.

Traditional prescriptive requirements for constituent materials, limiting water/binder ratios and cement contents are often not applicable for modern construction. The prescriptive design philosophy is largely based on the (often misleading) assumption that different concretes with similar mix proportions result in similar performance. With this approach, the combined influences of constituent material selection, construction procedures and ambient environmental conditions cannot adequately be accounted for.

In contrast, performance-based specifications relate to certain performance criteria that can be defined for a particular application. As such, performance-based specifications make demands on particular fresh or hardened concrete properties rather than on the concrete’s composition. Performance-based design and specification therefore include the testing of relevant concrete properties and the evaluation of test results based on agreed conformity requirements.

With the advancement of testing methods for concrete, performance-based design and specification of concrete and concrete structures is possible and already applied in practice. The most widely accepted performance-based design approach is for compressive strength, which has been used for more than a century. For many applications, however, compressive strength alone is not a sufficient performance indicator, as the relationship between compressive strength and other important properties may vary widely between different types of concrete.

More recently, performance-based design approaches in combination with suitable test methods were developed for concrete durability and are already applied in practice in some countries, which is covered in the work of RILEM TC 230 PSC. In addition to compressive strength and durability, other properties (e.g. elastic/plastic deformations, fresh concrete properties, thermal characteristics during and after hardening, strength development, ductility, crack resistance, etc.) need to be considered.

The aims of the workshop “performance based specifications for concrete” are to obtain an overview of the state of the art knowledge, to exchange results and to simulate the discussion between researchers and industry.


Workshop Topics:

- Concrete durability
- Elastic/visco-elastic deformations
- Fresh concrete properties related to workability
- Thermal characteristics during and after hardening
- Strength development
- Ductility
- Crack resistance
- Testing methods (destructive/ non-destructive)
- Performance prediction
- Quality assurance