A comparison of modal flexibility method and modal curvature method in structural damage detection

Vibration based damage detection techniques examines the changes in dynamic properties of a structure such as frequency, mode shape and damping to indicate the presence of damage. This method is preferred for its ease of implementation, non-destructive nature and its ability to identify damage that is invisible to the surface. Two vibration based damage detection methods are used in this study, namely Modal Flexibility Method and Modal Curvature Method. Although there have been numerous publications on these two methods, there is lack of study on the direct comparison of the methods. Finite element modal analysis of a reinforced concrete slab and steel frame was carried out to obtain the dynamic responses that were used to calculate the Modal Flexibility and Modal Curvature. The structural models were simulated using four damage cases: damage at single location, damage at multiple locations, damage at support location and damage at different damage severities. The comparison of the sensitivity and reliability of Modal Flexibility and Modal Curvature were evaluated using the results of these four damage cases. The results show that the sensitivity and reliability of both methods are affected by the size of the damaged area, its location relative to the support location and the number of damaged segments

THE PERFORMANCE OF ASP HAL TIC CONCRETE USING VARIOUS FILLERS

Asphalt concretes are made of asphalt binders and aggregates. Although asphalt cement is predominantly considered the binder holding the aggregates together, the actual product used to com1ect larger-size aggregate particles is the asphalt mineral filler mastics. It improves the resistance to permanent deformation in asphalt concrete mixtures by improvement of rheological properties of asphalt binders through a filler effect, and by acting as a microcrack arrester as well as improving the bonding interaction between asphalt binder and aggregates. Samples having different types of filler were prepared and optimum binder content was determined by Marshall Test procedure. Optimum filler content was determined considering the filler/bitumen ratio and filler ratio. Creep test, was carried out to determine the mixture properties and performance. Utilization of waste material as filler material shall reduce cost and contributes to the conservation of the environment without compromising the performance of the asphaltic concrete

THE PERFORMANCE OF ASP HAL TIC CONCRETE USING VARIOUS FILLERS

Asphalt concretes are made of asphalt binders and aggregates. Although asphalt cement is predominantly considered the binder holding the aggregates together, the actual product used to com1ect larger-size aggregate particles is the asphalt mineral filler mastics. It improves the resistance to permanent deformation in asphalt concrete mixtures by improvement of rheological properties of asphalt binders through a filler effect, and by acting as a microcrack arrester as well as improving the bonding interaction between asphalt binder and aggregates. Samples having different types of filler were prepared and optimum binder content was determined by Marshall Test procedure. Optimum filler content was determined considering the filler/bitumen ratio and filler ratio. Creep test, was carried out to determine the mixture properties and performance. Utilization of waste material as filler material shall reduce cost and contributes to the conservation of the environment without compromising the performance of the asphaltic concrete