Features

How Chinese Firms Build Highways in Kenya

They rely heavily on soil stabilization technology to deliver affordable roads.

Updated on

January 23, 2016

Machinery at a road construction site in Nairobi. PHOTO | FILE

Chinese contractors are increasingly building roads in Kenya amid complaints that government agencies favour them over local and other international firms.

In 2012, for example, three Chinese firms – among them China Wu Yi – completed the construction of Thika Road; an eight-lane, 50 km highway linking Nairobi to Thika.

The massive expansion project was completed in about two years, without locking out motorists – a feat that resonated very well with Kenyans.

Meanwhile, Chinese firms – China Road and Bridge Corporation (CRBC), China Wu Yi, Shengli Engineering Construction Group and Synohydro Corporation – are working on the northern corridor road project that links Mombasa and Nairobi to Ethiopia and South Sudan.

Other road projects under the powerful hands of the Chinese include Southern Bypass, Eastern Bypass, Northern Bypass, the dualling of Lang’ata Road, and Outering Road.

Chinese contractors rely heavily on soil stabilization technology to deliver fast, durable and affordable roads. Soil stabilization, which involves the addition of chemicals to on-site materials, is a way of improving the weight-bearing capabilities of subsoils, sands, and other waste materials to strengthen road surfaces.

Soil stabilization technology mainly relies on large amounts of clay owing to its inherent binding properties. Cement, bitumen, lime, tar emulsions and asphalt can be used as binding agents for producing a road base, although some of these materials are not eco-friendly.

Soil stabilization creates hydrophobic surfaces that prevent road failure from water penetration or heavy frosts by inhibiting the ingress of water into the treated layer. This produces road surfaces that are much more durable than regular road surfaces.