Take a look at the growth trends for green construction and building products.
Li W.C., Yeung K.K.A. Centre for Education in Environmental Sustainability and Department of Science and Environmental Studies, The Hong Kong Institute of Education, Hong Kong Special Administrative Region. Received 27 February 2014; accepted 20 May 2014
Green roofs have been established for over 100 years and they have been become one of the key elements in urban area in the past few decades. Many scientific researches focus on its cooling performance, efficiency and survival rates of plants. This article provides an overview mainly from two aspects, the vegetation on the green roofs and its benefits toward the surrounding environments. Vegetation is the key element in installing green roofs. It also provides some factors in choosing suitable plants on rooftops, factors including species that are drought tolerant, solar radiation tolerant, and cooling ability of plants. In addition, green roofs play a critical role in improving the urban environment by enriching the biodiversity, delaying the storm peak to the drainage system, diminishing the runoff quantity, purifying the air pollutants as well as the runoff quality.
Mohamadtaqi Baqersada*, Ehsan Amir Sayyafia, Hamid Mortazavi BakbaPh.D. Student, Department of Civil and Environmental Engineering, Florida International University, Miami, FL, USA.b Ph.D. Student, Department of Civil Engineering, Isfahan University of Technology, Isfahan, Iran.
During the past decades, there has been an extensive attention in using Ultra-High Performance Concrete (UHPC) in the buildings and infrastructures construction. Due to that, defining comprehensive mechanical properties of UHPC required to design structural members is worthwhile. The main difference of UHPC with the conventional concrete is the very high strength of UHPC, resulting designing elements with less weight and smaller sizes. However, there have been no globally accepted UHPC properties to be implemented in the designing process. Therefore, in the current study, the UHPC mechanical properties such as compressive and tensile strength, modulus of elasticity and development length for designing purposes are provided based on the reviewed literature. According to that, the best-recommended properties of UHPC that can be used in designing of UHPC members are summarized. Finally, different topics for future works and researches on UHPC’s mechanical properties are suggested.
Maureen E. Puettmann Research Associate and James B. Wilson Professor Department of Wood Science and Engineering
This study compares the cradle-to-gate total energy and major emissions for the extraction of raw materials, production, and transportation of the common wood building materials from the CORRIM 2004 reports. A life-cycle inventory produced the raw materials, including fuel resources and emission to air, water, and land for glued-laminated timbers, kiln-dried and green softwood lumber, laminated veneer lumber, softwood plywood, and oriented strandboard. Major findings from these comparisons were that the production of wood products, by the nature of the industry, uses a third of their energy consumption from renewable resources and the remainder from fossil-based, non-renewable resources when the system boundaries consider forest regeneration and harvesting, wood products and resin production, and transportation life-cycle stages. When the system boundaries are reduced to a gate-to-gate (manufacturing life-cycle stage) model for the wood products, the biomass component of the manufacturing energy increases to nearly 50% for most products and as high as 78% for lumber production from the Southeast.
The manufacturing life-cycle stage consumed the most energy over all the products when resin is considered part of the production process. Extraction of log resources and transportation of raw materials for production had the least environmental impact.