Concrete is a heterogeneous building material consisting of natural and man made products. The inherent heterogeneity of these material makes it hard to set a standard procedure for reactivity assessment. Common practice is to avoid reactive aggregates, where reactivity tests are either time consuming (impractical for engineers) or not reliable enough. Thus, there exists no internationally accepted ASR performance testing procedure; however studies on RILEM AAR-4 performance testing procedure is still in progress, yet not published. It is still a challenge to estimate the ASR effect on the existing structures together with potential impacts. There exist several recommendations, around the world, on ASR detection and prevention around the world. None, so far, has been internationally accepted.
In Netherlands, CUR regulations committee, CUR Technical Committee VC 62: Alkali Silica Reaction in concrete was set up in 2000. After severe criticism on CUR recommendation 38 (1994), the new committee published CUR recommendation 89 – ‘Measures to prevent damage to concrete by alkali-silica reaction (ASR)’ in 2002, which was followed by CUR recommendation 102 ‘Inspection and assessment of concrete structures in which the presence of ASR is suspected or has been established’. These recommendations are mostly provide decision trees suggest a ‘GO-NO GO’ decision.
A great number of studies, carried out worldwide, investigate the material performance considering various aspects of ASR effect. Most of these studies aim to determine the sole effect of ASR on micro-to-macro structural elements. Yet, there are missing links between chemical reaction parameters and gel product’s deleterious behaviour. Due to discontinuity of material properties in a mix, there may occur variations between laboratory test results and real structure measurements. A statistical approach to sample space data, harvesting available literature, can be used to increase the reliability of such a prediction model.
The aim of the project is to develop a material performance model for simulation of ASR effect on concrete durability. The final outcome of this project is an integrated support tool for engineers for ASR conscious design – a guideline for engineers.
