China would have no problem in winning a disproportionate share of big infrastructural projects if everyone plays fair and a fair system should be encouraged.
Obviously Chinese businesses and the Gov dont like to deal to deal with corruption in these countries. However thats how the things work there. China doesn't like it, but it cannot just abandon these markets, so it has to hold its nose and do business. Thats the reality of doing business in poor developing countries.
In recent years, progress has been made for combating such things by strengthening Chinese law and enforcement but, quite obviously, Chinese investigators cannot reach inside another another country and do their own investigation (big no-no, gives the appearance of disregarding their sovereignty)
What it can do is, to have its ambassadors on the ground to respond quickly to host countries reports about corruption by Chinese companies working there.
A similar thing happened in Kenya where, authorities/orgs alerted the Chinese ambassador to the wrong doing of some Chinese mining companies. China responded very fast and immediately ordered a complete recall of these companies back to China, for investigation and trial on court. CEOs and other top managers are going to be in big trouble now.
As I see you are interested in this topic, I would advice you to wait for the FOCAC 2021 forum between China and African countries which will happen in a few months. I expect that lot of new developments and initiatives will be announced there. Just something to keep an eye wrt China-Africa relations