Evaluation of cost-effective and energy-intensive procedures for recycling construction and demolition (C&D) wastes and selecting the most appropriate solution in District 15 of Tehran municipality based on analytic hierarchy process (AHP)

Nader Lotfi¹ Shiva Abbaspour² Nemat Dindarloo³

1) Head of green space center in district 15 of Tehran municipality
2) Head of green space Research and advice Center in district 15 of Tehran municipality
3) Master student of Tehran university

Publication : International Congress On Engineering, Technology and Innovation(eticong.com/1st)
Abstract :
The high amount of Construction and Demolition (C&D) wastes is produced in the macrocosm annually, which majority of them are ended up in landfills. In Tehran, for instance, it is calculated that almost 17 million tons of C&D waste were generated per year. This research investigates three scenarios of recycling C&D waste based on cost and energy consumption in the initial phase, and selecting the best choice by using an analytic hierarchy process (AHP) on the following phase. In the first stage, the portable crusher was applied for the first scenario to recycle concrete and then use it as base material at the same site. While in the second scenario, demolished concrete were delivered to the nearest landfill and new virgin aggregate from a concrete plant is purchased. For scenario three, demolished concrete were transformed to a recycling plant and purchase recycled concrete aggregate from the same recycling plant. Afterward the cost and energy consumption in these three scenarios were analyzed. In the second stage, the factors which contributed in recycling aggregate were investigated according to literature review and then evaluated. For this aim, qualitative measures are accompanied by using questionnaires for measuring criteria and sub-criteria, This valuation is taken away by a group of decision-makers coming from different fields, including construction engineer and people with the intention of providing a more accurate and mutually acceptable resolution. The weight matrices of criteria and sub-criteria are built by using pairwise numbers. The result have shown that, the first scenario is the most cost-effective and energy-intensive way to deal with concrete waste. Furthermore, first scenario by 41% weight is the best path for dealing with C&D waste compared with other two scenarios.
Keywords : Construction and Demolition (C&D) waste Recycling concrete Analytic hierarchy process (AHP).