Applying materials waste quantification to cement waste reduction in residential buildings of Tehran: A case study

The purpose of this research was twofold; first, it focused on developing quantitative wastage models for rebar, concrete, brick, and cement, as major traditional bulk building materials, used in Tehran residential buildings. The primary results indicated that multiple linear regression was an apt tool to model the effects of the studied variables on materials wastage. In every developed wastage model, subtractive or accumulative effect of each studied variable was recognized by its coeffcient value and sign. The developed models resulted in adjusted R2 values of 0.907, 0.875, 0.920, and 0.790, respectively, for rebar, cement, brick, and concrete waste. Cement, with average wastage of 8.57% by weight, was identified as the most wasted material verified by the case study. As the second objective of the study, the previously developed models as well as opinions of the project management experts were combined to propose a cement waste reduction guideline for traditional building construction, which is common in Tehran, Iran. With this purpose in mind, in the initial phase of the project, choosing lump-sum contract instead of cost-plus contract was considered. Moreover, a nancifial incentive reward scheme, with its economic viability and environment friendliness, was tested, which yielded positive results and hence, was proposed for the construction phase. Applicability of the proposed scheme was verified through a case study.