This paper reports on the assessment study conducted by the authors on the new Algiers airport building. The evaluation approach included visual inspection of the concrete, seismic parallel method for piles testing and non-destructive testing of concrete with Schmidt hammer, ultrasonic pulse velocity measurements, cores testing, carbonation tests and also ambient vibrations of the structure. The diagnostic confirmed that the concrete was of low strength and showed many shortcomings such as inappropriate mix design with respect to coarse aggregate size of concrete resulting in honeycombing, construction errors such as lack of cover and the use of low slump concrete, poor placement and inadequate vibration. The repair work involved the application of ready mixed cement based polymer modified sprayed mortar with and without fibers on more than ten thousand square meters of honeycomb concrete, the injection of about five hundred linear meters of cracks and the repair of about one hundred square meters of corrosion damaged concrete at a cost of more than three millions US dollars.