Superannuation funds must invest in “nation-building” projects to get competitive returns but the government should not expect them to carry any investment risk as a result, a doyen of the superannuation system, Don Russell, says.

Mr Russell, who chairs the $300 billion megafund AustralianSuper, said the “weight of money” held by the $3.5 trillion sector meant it needed to be open to “imaginative and innovative” assets such as infrastructure and housing.