UK contractors’ views on self-compacting concrete in construction

Abstract

Self-compacting concrete (SCC) is claimed to offer faster construction, safer sites and more consistent concrete quality, but little corroborative research data exist on performance advantages, particularly in comparison with traditional construction. Industry opinions also appear to be divided. For these reasons, an extensive interview programme was undertaken with UK contractors -from large national concrete frame contractors to small, locally based housebuilders -to assess whether benefits were being achieved and to try to understand the reasons why SCC is, or is not, being used. The 48 participants reported that decisions on the suitability of SCC were inherently complex and, if selected, there were challenges in understanding 'how' construction should be planned and managed to accommodate the use of SCC and to fully utilise its advantages. The findings identify the need for a step change in the industry's perception of SCC, such that it should be considered as a construction method, not simply as a material.

Optimising construction with self-compacting concrete

“…SCC reduces construction overheads and placement labour through the simplified construction process; however, they are not significant in the balance between options. Material price is the most significant factor for SCC; this reflects existing literature, which considers price as a major barrier to uptake (Concrete Society and BRE, 2005;Holton, 2003;Rich et al, 2012). The determining factor for conventional concrete is labour, where out-of-hours working is most influential.…”

“…Conventional methods combine compaction and levelling processes through tamping and screeding, a highly intensive and physically demanding activity; this intensity was apparent in the manipulation of the concrete -it requires more physical effort to manually level and power float the slab, whereas SCC's fluid nature requires minimum work (dappling) to achieve a similar result. The literature also claims that material cost was a prohibitive factor in SCC's further adoption (Concrete Society and BRE, 2005;Rich et al, 2012). The three cost modelling scenarios have demonstrated that financial savings can be realised through SCC, subject to several conditions.…”

“…Here, SCC was selected in response to specific challenges, for instance to create very high-quality, complex and detailed facades. SCC is rarely selected as a 'first choice' construction option in its own right, yet the literature confirms that the material has a broader range of benefits than this 'single attribute' decision making might suggest (Williams, 2008 Rich et al (2012) conclude that strategic change is a direct result of considering SCC as a construction method rather than a material, invoking engagement with SCC earlier in the construction process during design and planning with greater potential to adapt construction to realise other benefits.…”

“…It is used in many mainstream construction projects because of its flowing nature and early maturity; it is generally considered to be an innovative material that is more expensive than conventional concrete mixes. Higher initial material cost seems to be the most significant barrier to greater adoption (Concrete Society and BRE, 2005;Rich et al, 2010Rich et al, , 2012, but its placement is claimed to be faster and more reliable than conventional concrete (Khayat et al, 2001;Okamura and Ouchi, 2003). Therefore, directly comparing SCC with conventional mixes, simply on the basis of material cost, is inappropriate and inaccurate.…”

Editorial

“…Considerable research exists into the properties of SCC as a material but none has considered the views of industry on its wider benefits in the construction process. This has now been remedied and reported in the paper by Rich et al (2012). From interviews with large and small size UK contractors the authors conclude there is no general agreement on the wider role of SCC and report that it is still mainly only being considered as a material to overcome particular construction problems.…”