The brittleness of cement composites makes cracks almost inevitable,producing a serious limitation on the lifespan,resilience,and safety of concrete infrastructure.To address this brittleness,self-healing concrete has...The brittleness of cement composites makes cracks almost inevitable,producing a serious limitation on the lifespan,resilience,and safety of concrete infrastructure.To address this brittleness,self-healing concrete has been developed for regaining its mechanical and durability properties after becoming cracked,thereby promising sustainable development of concrete infrastructure.This paper provides a comprehensive review of the latest developments in self-healing concrete.It begins by summarizing the methods used to evaluate the self-healing efficiency of concrete.Next,it compares strategies for achieving healing concrete.It then discusses the typical approaches for developing self-healing concrete.Finally,critical insights are proposed to guide future studies on the development of novel self-healing concrete.This review will be useful for researchers and practitioners interested in the field of self-healing concrete and its potential to improve the durability,resilience,and safety of concrete infrastructure.展开更多
Dynamic</span></span><span><span><span style="font-family:""><span style="font-family:Verdana;"> urbanization of African cities has created development traj...Dynamic</span></span><span><span><span style="font-family:""><span style="font-family:Verdana;"> urbanization of African cities has created development trajectories that face systemic challenges in the provision of sustainable and ecologically resilient urban environments. The specific challenges include extensive unregulated growth with informal settlements reflecting poor service levels and high poverty indices, inadequacy in </span><span style="font-family:Verdana;">provision</span><span style="font-family:Verdana;"> of basic services in health, water, housing, transport </span><span style="font-family:Verdana;">and</span><span style="font-family:Verdana;"> communication infrastructure, high reliance on biomass fuels, exposure to environmental stress </span><span style="font-family:Verdana;">and</span><span style="font-family:Verdana;"> implausible climate change coping and mitigation mechanisms among others. </span><span style="font-family:Verdana;">Review</span><span style="font-family:Verdana;"> of extensive literature and synthesis of existing bodies of knowledge on the ecological and management perspectives of urban environments revealed many gaps and understanding of urban transformation processes. The purpose of this review was to contextualize credible pathways for optimization of both ecosystem goods and services from green urban landscapes (Green infrastructure) and non-green infrastructure to ensure sustainable and ecologically resilient urban environments. Attempts were made to rationalize and validate through discussions the benefits of managed urban ecosystems for African cities. </span><span style="font-family:Verdana;">On the basis of</span><span style="font-family:Verdana;"> the evidence from the literature, it is concluded that urban development trajectories that do not embrace multifaceted approaches that deliberately retain and maintain green infrastructure in the urban environment may not be cost-effective. It is recommended that systematic integration of urban forestry concepts in urban p展开更多
文摘The brittleness of cement composites makes cracks almost inevitable,producing a serious limitation on the lifespan,resilience,and safety of concrete infrastructure.To address this brittleness,self-healing concrete has been developed for regaining its mechanical and durability properties after becoming cracked,thereby promising sustainable development of concrete infrastructure.This paper provides a comprehensive review of the latest developments in self-healing concrete.It begins by summarizing the methods used to evaluate the self-healing efficiency of concrete.Next,it compares strategies for achieving healing concrete.It then discusses the typical approaches for developing self-healing concrete.Finally,critical insights are proposed to guide future studies on the development of novel self-healing concrete.This review will be useful for researchers and practitioners interested in the field of self-healing concrete and its potential to improve the durability,resilience,and safety of concrete infrastructure.
文摘Dynamic</span></span><span><span><span style="font-family:""><span style="font-family:Verdana;"> urbanization of African cities has created development trajectories that face systemic challenges in the provision of sustainable and ecologically resilient urban environments. The specific challenges include extensive unregulated growth with informal settlements reflecting poor service levels and high poverty indices, inadequacy in </span><span style="font-family:Verdana;">provision</span><span style="font-family:Verdana;"> of basic services in health, water, housing, transport </span><span style="font-family:Verdana;">and</span><span style="font-family:Verdana;"> communication infrastructure, high reliance on biomass fuels, exposure to environmental stress </span><span style="font-family:Verdana;">and</span><span style="font-family:Verdana;"> implausible climate change coping and mitigation mechanisms among others. </span><span style="font-family:Verdana;">Review</span><span style="font-family:Verdana;"> of extensive literature and synthesis of existing bodies of knowledge on the ecological and management perspectives of urban environments revealed many gaps and understanding of urban transformation processes. The purpose of this review was to contextualize credible pathways for optimization of both ecosystem goods and services from green urban landscapes (Green infrastructure) and non-green infrastructure to ensure sustainable and ecologically resilient urban environments. Attempts were made to rationalize and validate through discussions the benefits of managed urban ecosystems for African cities. </span><span style="font-family:Verdana;">On the basis of</span><span style="font-family:Verdana;"> the evidence from the literature, it is concluded that urban development trajectories that do not embrace multifaceted approaches that deliberately retain and maintain green infrastructure in the urban environment may not be cost-effective. It is recommended that systematic integration of urban forestry concepts in urban p