Sierra Leone on Wednesday scrapped a $400m scheme for a Chinese-built airport, saying the scheme was too costly.In a statement, the ministry of transport and aviation said that "after serious consideration and due diligenc", the government had determined the Mamamah International Airport initiative was "uneconomical". All contracts under the project are being terminated, it said.Sierra Leone's previous president, Ernest Bai Koroma, signed a loan agreement with China for the airport shortly before elections in March that his party lost.His successor, Julius Maada Bio, vowed to stop the scheme. He also lashed Chinese infrastructure projects generally as "a sham" that brought the impoverished west African state scant economic benefit.The scheme entailed building a new airport around 50km outside the capital of Freetown.It would be completed in 2022 and managed and maintained by the Chinese.* Sign up to News24's top Africa news in your inbox: SUBSCRIBE TO THE HELLO AFRICA NEWSLETTERFOLLOW News24 Africa on Twitter and FacebookBut critics questioned the benefit, given that Freetown's existing airport, Lungi, is operating below capacity.The government on Wednesday said it was looking into the possibility of building a bridge between Freetown and Lungi airport - a scheme that has been priced at more than $1 billion.The airport and another major Chinese project, a toll road, shouldered their way into Sierra Leone's presidential election in March.Several candidates declared the schemes were unaffordable and should be scrapped or reviewed.Bio went furthest, going on record as saying "most of the Chinese infrastructural projects in Sierra Leone are a sham with no economic and development benefits to the people."China has provided infrastructure and development aid to Africa since the Cold War.Debt trap But its interest and presence in the continent have grown exponentially in the past two decades, in parallel with its emergence as a global economic giant.China overtook the United States in 2009 as Africa's biggest trading partner.Chinese loans, meanwhile, have soared, especially in transport and energy infrastructure.Some analysts have warned of a debt trap as some of the world's poorest states struggle to repay their borrowings.Between 2000 and 2017, China's government, banks and contractors lent African countries $143 billion, according to the China-Africa Research Initiative at Johns Hopkins University in Washington.