Search

Previous studies have shown that RC flat slab buildings are highly vulnerable to progressive collapse because no beams could help redistribute the loads previously carried by the lost columns. The necessary strengthening methods should, therefore, be adapted to reduce the occurrence of progressive collapse. In this paper, the progressive collapse behaviour of five-storey R.C flat slab building is assessed by removing columns from the first-storey and dynamic analysis is conducted in compliance with GSA guidelines (2016). The results are analyzed in terms of vertical displacement and chord rotation at the location of removed columns and compared with the allowable limits as specified in DoD guidelines (2009). Different sized perimeter beams are used as strengthening methods to increase the progressive collapse resistance of the studied flat slab building. Since building strengthening uses structural elements that consume natural resources, sustainability criteria should be explicitly included in the strengthening requirements. These performance enhancement methods are then evaluated from structural, cost and environmental aspects and the results are examined. A strengthening alternative is then proposed which not only satisfy the progressive collapse code requirements but also requires less cost and emits less CO 2 gas. [ABSTRACT FROM AUTHOR]

In recent years, construction industry has seen huge demand for non-renewable materials such as stones, fine aggregate, coarse aggregate, etc., resulting in exponential growth in mining operation. In parallel to this, the quarrying of dimensional stone generates vast amount of waste in both solid and powder forms. Sustainable disposal of these wastes has emerged as a big challenge around the globe. The present research focusses on minimizing the environmental pollution which is often due to unplanned disposal of slurry waste generated during the cutting process. To carry out this study, eleven mortar mixes were prepared with dimension limestone slurry waste as a replacement of fine aggregate. These mixes were tested for their workability, porosity, ultrasonic pulse velocity, dynamic modulus of elasticity, water absorption, compressive strength, flexural strength and adhesive strength. The behavior of internal structure of mortar matrix was evaluated on selected mixes by TGA, FTIR, SEM and MIP techniques. Tests results revealed that up to 40 percent replacement of fine aggregate with dimensional limestone slurry improved strength and sustained necessary rheological parameters of mortar mixes. Results of microstructure studies substantiate these improvements. [ABSTRACT FROM AUTHOR]