CHINA has entered a new phase in its modern-day scramble for Africa by moving to rebuild 3300 kilometres of roads in the Democratic Republic of Congo.

The project is part of China's largest single investment in Africa - a $A9.2 billion services-for-minerals deal signed in January.

China has also promised to repair more than 3000 kilometres of largely defunct railways, build 32 hospitals and 145 health centres, install two electricity distribution networks, and construct two hydroelectric dams and two airports.

In return, it has won the rights to five copper and cobalt mines in the Congo's southern minerals belt.

The deal extends Beijing's dominance over parts of Africa previously allied to the West.