A Framework for Optimizing Lap Splice Positions within Concrete Elements to Minimize Cutting Waste of Steel Bars

One of the material waste streams in the construction of concrete structures is the waste generated during cutting of steel bars to their final required length. The amount of waste generated to produce the required length of steel bars can be affected considerably by the cutting patterns adopted. Waste can, therefore, be minimized by optimizing the cutting pattern to be selected. Cutting patterns are a combination of bar lengths and, thus any change in the required lengths directly affects cutting patterns and the final amount of waste. This paper presents a framework for selection of the location of lap splices, through generating all possible lapping patterns, which define the bar lengths in cutting patterns. The focus is placed on steel bars used in concrete columns as their arrangement is affected by multiple parameters that make the manual preparation of shop drawings a tedious job. The developed framework is applied to a case study involving the construction of columns for an actual 6 storey building. The estimated waste produced after the adoption of optimal lapping patterns is compared with the actual waste generated based on the project shop drawings. The results indicate that considerable reduction in the steel bars wasted is achievable by optimizing the lapping patterns.