The effect of climate change and low CO2-binders on the service life of concrete structures due to carbonation
article
Carbonation of concrete is strongly affected by local climate conditions but degradation models do not take this fully into account. Hence an updated model is presented including both an extension of the (environmental) loads as well as the resistance of the concrete against these loads. Loads from the environments that are included are CO2 concentration, relative humidity and time of wetness. The data is based on historical data of the Dutch weather stations across the country, and extrapolated based on the current climate changing trends. The resistance against carbonation has been modelled in more detail by including the principal concrete composition parameters. The climate effects on carbonation have been demonstrated for three types of cement, with a variable amount of calcium content and with a different pore fineness in the hardened state. The results of the modelling indicate a significant increase in carbonation depth for hardened binders that dry out under the current relative humidity. The change in carbonation rate is however dramatic for those cements that currently remain saturated at the prevailing relative humidity but will dry out due to the lower RH as a consequence of climate change. Their carbonation rate increases so much that the service life may be compromised. This first assessment of the climate change effects on carbonation, couples to the drive towards low or no clinker-based binders warrants urgent further research towards the effect of these binders both at the current and the future climate.
TNO Identifier
1014738
Source
Heron, 69(2), pp. 125-142.
Pages
125-142