Yesterday Friday 17th August 2018 at about 14.00hrs or 2pm, NBRRI was alerted about a building collapse at IT Igbani/NBRRI road, Off Obafemi Awolowo road, Jabi – Abuja. Because we have continuously used this route to the new NBRRI Head Office and Abuja Laboratories at 10 IT Igbani/NBRRI road, we have seen the structure always but since it is no one’s business to stray into someone else’s premises, it barely caught anyone’s attention.
On getting to Site at about 2.15pm, we noticed the building in a pile of rubble with rescue workers that arrived earlier struggling to remove debris to rescue lives with hand and crude tools. We sympathize with the families of those who lost loved ones and pray for speedy recovery of those injured.
The building is a framed structure of 4-storeys whic
1. Based on the length of time that the structure was left abandoned, resumption of work on Site should have been preceded by integrity tests and some remediation done on concrete elements whose concrete deteriorated under years of carbonation resulting in the leaching out of bonding mortar.
2. As the electronic media (television and social network) would have captured in their recordings, there has been total disintegration and dissociation of concrete from the steel reinforcements pointing to a notion that the concrete used was weak and did not develop sufficient bond to act in unison as a composite single element to resist relative sliding between steel and concrete.
3. Incidentally some NBRRI Staff have said they had taken note of the unusually slender column support elements and that these were being knocked recklessly with no due regard to their functions that could impair their load carrying capacity and induce a collapse at any time.
4. NBRRI in many previous reports has highlighted the unprofessional use of sandcrete blocks to beef up columns and beams in their structural roles. It has worked but is not necessary and in this building, a pure structural framing construction was commendably done but unfortunately structurally incompetent leading to failure.
5. Because of rescue operations, NBRRI has no way of inspecting the foundations to ascertain if they have a blame in the failure. In due course, attempts will be made to inspect the foundations and form an opinion.
6. There was evidence of both fresh and new concrete on site inferring that work was ongoing at the time of construction. Unfortunately, both hardened and fresh concrete spilled and disintegrated during collapse.
7. The Director of Development Control of FCT was present on Site and was advised to arrest the Owner of the Building as well as the Contractor and Professional team of Architects, Builders and Engineers, if they exist at all, because some Building Owners are their own engineers relying heavily on quackery for implementation.
8. NBRRI has a 5-story building not far from the collapsed Site and a lot of care was taken when construction was restarted after 12-years of abandonment to inject fresh cement mortar into all concrete elements including floors and beams to rejuvenate lost capacity resulting from years of carbonation and leaching of mortar.
9. Every Site abandoned for years must be reassessed, redesigned and the structural competency assured before resumption of further construction.
10. NBRRI experience has revealed that Building Service Workers for Electricity, Water and Sewage Disposal as well as ICT lines are very unsympathetic to structural integrity. They drill small and large holes through very sensitive and intensely loaded beams and columns with no idea that it could collapse on them because they are undermining stability. They undermine foundations for services and weaken footings through ground softening by directing precipitation to excavations beneath buildings with no idea what dangers their activities pose.
11. A journalist asked me whether this has not represented failure on our part for past efforts and I told him a definite NO because our interventions over the years have produced numerous results.
12. Even though we must develop zero-tolerance to Building, Bridge collapses and Road failures, nonetheless the last Building collapse recorded in Abuja is some 4-years ago somewhere in Gwarinpa Extension or thereabouts which we investigated. Building collapses have gone down from 33no in one year (2012) in Lagos and 22no in Abuja in 2012 to almost zero. This is the first collapse brought to NBRRI attention this year in Nigeria.
13. The supervision of buildings is the square responsibilities of Municipal Development Control departments in cities and states who must be on their toes in regulating development as well as actively punishing offenders to act as deterrent for the future.
13. NBRRI and R&D outfits, especially Universities, and Professional Regulators such as COREN, ARCON, TOPREC, etc, are available to control practice and to provide scientific, technical and professional benchmarking for guidance. It is up to Municipal Control Authorities to institute checks and balances for practice within their domains, be it in Abuja, Lagos, Jos, Kano, Portharcout, Onitsha or any place in this country at all.
14. It is important to advice all developers to harness and use the services of intelligent and experienced registered professionals on their structures and avoid cutting corners in reinforcements and concreting; but most importantly to ensure that the foundations are properly designed and constructed based on proper field investigations. Using good artisans and craftsmen that are well informed, which comes primarily at the construction stage, is also useful because they could raise alert at flaws in design and construction sequence, procedure and optimal use of materials to avert shoddy works.
Engr Professor Danladi S MATAWAL, fnse, faeng, fnice.
Director-General/CEO, Nigerian Building & Roads Research Institute, NBRRI-FMST, Abuja.