Ecological Assessment of Clay Brick Manufacturing in China Using Emergy Analysis

Junxue Zhang,Changhai Peng,Ravi S Srinivasan

doi:10.3390/buildings10110190

Junxue Zhang, Changhai Peng + Show 1 more

Open Access

https://doi.org/10.3390/buildings10110190

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Abstract

Clay brick is a commonly used building material in China. Due to the enormous land destruction and excessive consumption of resources, such as materials and energy in the manufacture of clay brick, it is important to study its overall sustainability, i.e., in terms of impact on the environment, services, and economy. In this study, emergy analysis is employed, which offers a holistic perspective, unlike typical environmental studies. A series of emergy indices such as renewability rate (R%), nonrenewability rate (N%), unit emergy values (UEVs), emergy yield ratio (EYR), environmental loading ratio (ELR), and emergy sustainability index (ESI) were used to study manufacturing of clay brick. In addition to calculating UEVs of clay brick manufacturing in China (7.18 × 1012 sej/kg), our detailed analysis shows that the nonrenewable resources and imported energy have a dominant impact on the emergy contribution (50.6%) and within the nonrenewable resources, clay is the foremost item, accounting for 33.5% of local emergy inputs. Given different electricity UEVs, the change ranges of clay brick system UEVs are 14.9% (scenario 1), 7.24% (scenario 2), 8.91% (scenario 3), and 6.94% (scenario 4). Furthermore, several policy suggestions are discussed for improving the sustainability of the evaluated system, involving the energy structure adjustment, recycling material replacement, and promotion of energy-saving systems.

Highlights

Before the advent of cement-based materials for buildings, clay bricks were one of the most commonly used materials for more than two thousand years in China, as seen in ancient buildings [1,2].Despite China’s rapid growth from the reform in the 1980s [3], clay bricks continued to be used in building construction in rural areas
While much attention has been aimed at cementitious bricks in terms of sustainability assessments, the research community has rarely focused on the overall sustainability, i.e., in a holistic perspective, of clay bricks in China
Sustainability demonstrates the concept of the triple bottom line, which is a comprehensive dimension study related to the environment, society, and economy

Summary

Introduction

Before the advent of cement-based materials for buildings, clay bricks were one of the most commonly used materials for more than two thousand years in China, as seen in ancient buildings [1,2]. Despite China’s rapid growth from the reform in the 1980s [3], clay bricks continued to be used in building construction in rural areas. Sustainability is an important concept and central issue which is widely used in various fields such as supply chain management [4], engineering analysis [5], building construction program [6], information aspect [7], tourism growth [8], agricultural directions [9], national sustainability [10], urban assessments [11], groundwater sustainability assessment [12], dryland regions [13], and campus culture [14].

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