Award-winning paper in 2017

The Magazine of Concrete Research Prize, awarded for the best paper published in Magazine of Concrete Research, was awarded to Elgalhud et al. (2017).

Systematic analysis and evaluation of experimental results on carbonation and carbonation-induced corrosion resistance of concrete made with Portland limestone cement (PLC) are presented; these results have been extracted from 143 globally published studies in the literature since 1986, by 274 researchers from 131 institutions and 34 countries, and yielding a 19 000 data matrix are presented. It is shown that the carbonation of concrete increases with increasing limestone content, within the range permitted by standard BS EN 197-1:2011. This effect, however, is less marked for concrete designed on an equal strength basis to the corresponding Portland cement (PC) concrete than concrete designed on an equal water/cement (w/c) basis. Eurocode 2 standard specifications for XC3 carbonation exposure for characteristic cube strength of concrete (or its w/c ratio) may need to be reviewed for the addition of limestone. Other influencing factors: curing, limestone fineness, total cement content, were also studied. A comparison has been conducted for the carbonation performance of concrete made with PLC and cement containing fly ash and ground granulated blast-furnace slag. Procedures to reduce the carbonation of PLC concrete are proposed. Response to accelerated carbonation, at 3–5% carbon dioxide concentration, of PLC concrete is similar to natural indoor exposure. A conversion factor of 1 week accelerated carbonation equal to 0·75 year natural indoor exposure was determined.