The Kenya Bureau of Standards (Kebs) on Tuesday said that, beginning April 1, 2017, builders will only be allowed to use ribbed steel bars for reinforcement of concrete – in what is expected to boost construction safety.
“(Following) a meeting between Kebs management and representatives of the steel industry and the Kenya Association of Manufacturers, it was resolved that as from April 1 , 2017, only ribbed bars shall be manufactured and offered for sale in the country,” said Kebs managing director Charles Ongwae.
In recent years, twisted bars – which are commonly used locally – have been phased out in most developed countries due to their poor bonding and structural properties.
The material has been replaced with ribbed (deformed) bars that bear ribs or projections on their surface to provide better anchoring for concrete.
James Musembi a structural engineer based in Nairobi admits that ribbed steel bars are superior to their twisted counterparts and the move to outlaw the weaker material is welcome.
“Ribbed bars offer better bonding with concrete when used as reinforcement and this increases the overall bearing capacity of the individual unit where the bar has been used,” Mr Musembi said in an interview, adding that the bars can slash reinforcement costs by up to 40 per cent.
The twisted steel bars ban comes at a time when Kenya is grappling with rising cases of building collapses – most of which have been blamed on the usage of substandard construction materials and poor workmanship.
On November 10, for example, a 10-storey building collapsed in Kisii town killing eight people and injuring 43 others. Preliminary findings of an investigation by the State showed that, among other issues, the builder had used poor quality steel bars and substandard concrete mix.