Are the architects, quantity surveyors and engineers so good? This lot is sometimes bad for both the investors and residents. But this is set to change as the discovery of the rebound hammer promises to offer peace of mind.
Dr. Raul Figueroa, the CEO of Questworks Limited and the Director for the Establishment of Strathmore’s School of Engineering, for his PhD dissertation at the Carnegie Mellon University in Pittsburg, USA, carried out a research on the “Structural integrity of buildings in Kenya” aimed at offering solution to unprompted collapse of buildings in Kenya, which, over the years, have led to the death of over 80 people, and another 290 injured.
The study was conducted on 51 buildings within Nairobi’s Central Business District where the concrete strength of buildings was measured. Concrete strength is measured in Megapascal (MPa). – Although Pascal (Pa) is the SI unit of measuring tensile strength, Megapascal (MPa) is equal to 1,000,000 Pa. The accepted standard for concrete strength in Kenya is 25 MPa. In cases where buildings are very weak, an increase in the load carried by a building may make the building collapse.
Findings from the research reveals that 75% of the buildings surveyed were built (or in the process of being built) using concrete that did not meet the standards that had been specified by the structural engineers in charge. The concrete used in those buildings, and certified as compliant with specification, is in fact, on average, 36% weaker than the certificates say. The approvals from the architects and engineers are based on the (inaccurate) certificates.
In other areas around Nairobi, such as Buruburu and Eastlands, a survey of 25 buildings showed that 100% of the tested concrete was weaker than required by design. In this case the concrete was close to 40% weaker. Further, 90% of the results from concrete testing laboratories that had been used to certify the quality of the concrete used to build were wrong when compared to the findings of the actual concrete testing carried out by Figueroa and his team. The data shows that the quality control mechanisms for structural concrete currently used in Kenya are not as effective as they should be. Architects and engineers routinely certify buildings as safe for occupation based, in part, on inaccurate or false laboratory reports.
Experts who were surveyed predicted almost perfectly as a group the poor quality of concrete used in buildings in Nairobi. Their prediction matched the true situation. This implies that professionals involved in the construction industry are aware that something is wrong with the current quality control practices in Kenya.
Computer simulation models show Nairobi losing between 1.5 and 2.5 million square meters, which translate to between 800 and 3,500 residential and commercial buildings, along with thousands of deaths and injuries, and over $3 billion in reconstruction. This would have catastrophic effects for Kenya’s capital. The reality is, in the event of a 6 Ritcher earthquake, Kenya would lose from 1.5 – 2.5Million square meters, which translates to about 800 – 3500 residential and commercial buildings. About 1.5M people would also be affected either through death or loss of shelter.
Moved by the recent collapses in Kiambu, Roysambu, Kisii, Makongeni, among others which have increased the loss of lives and destruction of property in the construction industry, Questworks, an integrated project delivery firm that combines architectural design, engineering, project management, finance and risk analysis, and construction expertise will lend –for free- new impact hammers to developers and buyers interested in verifying the quality of their concrete.
The good thing is Questworks is lending rebound hammers to engineers, building developers, property buyers and tenants. A person purchasing a home would now be able to know if they are buying a weak building. One can also test and ascertain adherence to the standards by contractor as the construction progresses. The firm also intends to provide free testing for strength of reinforcing steel. All this is in an attempt to empower ordinary Kenyans in taking charge of safety of buildings they live in.
To further contribute to improving the quality and safety of new structures, Questworks is sponsoring the development of a Quality Control App, designed by researchers at the Center for Analysis of Regulation and Policy at Strathmore University in collaboration with a team of programmers at Carnegie Mellon University in the US. The App will be launched later this year.