Construction and demolition waste – CDW which happens to be derived from building sites as well as demolitions, has in it a variety of materials such as inert substances like concrete as well as bricks, and of course some non-inert materials like wood and plastic in addition to toxic elements like heavy metals.
These materials get frequently disposed of by way of unsustainable methods such as incineration, thereby leading to prominent environmental issues like greenhouse gas emissions, land degradation as well as rapid landfill depletion.
The researchers under one of the studies have gone on to utilize certain specific environmental impact indicators like global warming potential as well as resource consumption in order to evaluate numerous CDW management scenarios.
Traditionally, most of the studies have made use of Life Cycle Assessment – LCA in order to analyze environmental impacts pertaining to processes like demolition, recycling, transportation as well as landfilling. LCA goes on to evaluate the waste effects of a product or process all across its lifecycle, thereby focusing on carbon emissions as well as resource utilization. But these studies often go on to neglect a multi-indicator analysis which includes major elements such as energy recovery.
It is well to be noted that accurate data collection as well as segregation happen to be essential when it comes to effective environmental impact evaluation of CDW. These assessments need a detailed quantification of CDW by way of type, quantity as well as location. Traditional methods like on-site direct measurement surveys which go on to capture weight and volume, happen to be labor-intensive, costly, and also time-consuming. Furthermore, while estimations which are based on material inventory as well as flow are effective when it comes to a regional scale, they sort of fall short in terms of accurately addressing waste coming from individual building demolitions.
The fact is that Building Information Modeling – BIM happens to offer a more efficient solution to such kind of data collection challenges.
Proposed BIM-based Evaluation
BIM- Building Information Modeling happens to be an information management process which gets used all across the building’s lifecycle, thereby focusing on the collaborative usage of semantically rich 3D building models. This sort of framework facilitates rapid, systematic collection of precise data. When mixed with suitable waste indicators, BIM can go on to address intricate quantification issues within the CDW management.
The researchers in one of the studies have integrated BIM-LCA approach in order to establish a conceptual framework which can go on to effectively assess different CDW management practices. BIM has been employed to estimate the exact CDW information as well as mathematical formulas happened to be used in order to quantify the effect when it comes to the indicators. BIM data, post that was fed back to the LCA method for a more absolute assessment in terms of CDW management with a perspective of global warming potential as well as resource consumption.
The life cycle model pertaining to the CDW considered all the three stages, which included generation, transportation as well as disposal so as to ensure an absolute impact assessment. CDW happened to get categorized into three groups in which Group A was metal, plastic, timber, glass, while Group B happened to be concrete, cement, brick, ceramic tile and Group C consisted of mixed fragments.
When it comes to data collection, the Revit 2016 software got employed to simulate architectural as well as the structural details of buildings such as main structural elements like columns, walls, doors, materials such as concrete, brick, glass and also utility installations like plumbing and electrical systems, predominantly plastic. The data happened to be sourced from field surveys, literature reviews as well as publicly available databases.
Drawing on the real-world examples, researchers went on to propose three distinct CDW management point of views in order to identify environmentally friendly choices.
The first scenario goes on to embrace a resource-product-waste economic model having less than 5 % recycling as well as reuse, primarily pertaining to high-value metals. The second scenario happens to follow an open 3R- reduce, reuse, recycle kind of strategy, thereby aiming to minimize the landfill flow and at the same time also manage final disposal effectively. The third scenario goes on to advocate for a circular economy, keeping in mind today’s products as well as tomorrow’s resources, hence promoting a sustainable cycle within a resource-limited world. This approach goes on to assume that materials which are sold in the market can go ahead and completely substitute for the raw materials and that the materials processed in the recycling facilities can go on to replace natural materials entirely.
Importance of the Work
A circular economy kind of a strategy, which goes on to efficiently reuses plastics, wood, glass as well as metals, happens to generate recycled aggregates from the cement and concrete, recycles ceramics as well as bricks, and at the same time also utilizes remaining waste in the energy recovery, has gone on to demonstrate a considerable efficacy when it comes to reducing the carbon emissions by up to 6.641 × 105 kg CO2 eq. Moreover, it goes on to conserves resources and also prevents 4.601 × 107 MJ energy consumption, hence significantly mitigating the impacts on the environment.
While the research happens to be specific to high-rise residential buildings, principles and framework which have been developed can as well be applied to numerous building types. But it is quite significant to note that the results go on to assume ideal conditions in CDW management, that may as well represent a best-case scenario.
Despite such kind of limitations, the study goes on to promote innovative building management and at the same time also encourages the adoption when it comes to sustainable practices within the built environment by way of BIM. Given the strong and fast pace of industrialization as well as urbanization, that itself heightens environmental and also health risks associated with the CDW, these findings can go on to provide a foundation when it comes to the governmental bodies in order to develop some really impactful CDW management policies.
