A large share of urban freight in cities is related to construction works. Construction is required to create attractive, sustainable and economically viable cities. When activities at and around construction sites are not managed effectively, they can have a negative impact on the cities liveability. Construction companies implementing logistics concepts show a reduction of logistic costs, less congestion around the sites and improved productivity and safety. The client initially sets the ‘ground rules’ for construction in the tendering process. This paper explores how tendering for construction projects can support sustainable urban construction logistics. We explore the potential for tendering construction projects, by both public and private clients, for sustainable urban construction logistics and we present a conceptual framework for specifying ‘logistics quality’ as a quality criterion for EMAT (Economically Most Advantageous Tender). Our exploration results in questions for further research in tendering for sustainable urban construction logistics.
from the article: "Abstract The way in which construction logistics is organised has considerable impact on production flow, transportation efficiency, greenhouse gas emissions and congestion, particularly in urban areas such as city centres. In cities such as London and Amsterdam municipalities have issued new legislation and stricter conditions for vehicles to be able to access cities and city centres in particular. Considerate clients, public as well private, have started developing tender policies to encourage contractors to reduce the environmental impact of construction projects. This paper reports on an ongoing research project applying and assessing developments in the field of construction logistics in the Netherlands. The cases include contractors and third party logistics providers applying consolidation centres and dedicated software solutions to increase transportation efficiency. The case show various results of JIT logistics management applied to urban construction projects leading to higher transportation efficiencies, and reduced environmental impact and increased production efficiency on site. The data collections included to-site en on-site observations, measurement and interviews. The research has shown considerable reductions of vehicles to deliver goods and to transport workers to site. In addition the research has shown increased production flow and less waste such as inventory, waiting and unnecessary motion on site."
Productivity in construction is relatively low compared to other industries. This is particularly true for labour productivity. Problems that contribute to low labour productivity are often related to unorganised workspace, and inefficient organisation of work, materials and equipment. In terms of time use, site workers spend time on various activities including installing, waiting, walking etc. In lean production terms time use should be value adding and not wasteful or non-value adding. The study reported in this paper has endeavoured to measure the time use and movement applying an automated data system. The case study reflected a limited application to a specific kind of activity, namely doors installation. The study investigated time use and movements based on interviews and on automated detection of workforce. The interviews gave insights in the time build-up of work and value-added time use per day. The automated tracking indicated time intervals and uninterrupted presence of site workers on work locations giving indications of value adding time. The time measurements of the study enable comparison of time use categories of site workers. The study showed the data system calculated the same amounts of productive and value adding time one would expect based on the organisation and characteristics of the work. However, the discussion of the results underlined that the particular characteristics of individual projects and types of team work organisation may well have an impact on productivity levels of workers. More application and comparative studies of projects and further development and extension of the automated data system should be helpful.
Recent research by the renowned Royal Institution of Chartered Surveyors (RICS) shows that more than 2/3 of all CO2 is emitted during the building process and less than 1/3 during use to heat the building and the tap water. Lightweight, local and biobased materials such as biocomposites to replace concrete and fossil based cladding are in the framework of climate change, a necessity for future building. Using plant fiber in polymer composites is especially interesting for construction since natural fibers exhibit comparative good mechanical properties with small specific weight, which defines the potential for lightweight constructions. The use of renewable resources, will affect the ecosystem favorably and the production costs of construction materials could also decrease. However, one disadvantage of natural fibers in plastics is their hydrophilic properties. In construction the materials need to meet special requirements like the resistance against fluctuating weather conditions (Ticoalu et al., 2010). In contrast to synthetic fibers, the natural ones are more moisture- and UV-radiation-sensitive. That may lead to degradation of these materials and a decreasing in quality of products. (Lopez et al., 2006; Mokhothu und John, 2017) Tanatex and NPSP have approached CoE BBE/Avans to assist in a study where fibres impregnated with the (modified) Tanatex products will be used for reinforcement of thermoset biopolymers. The influence of the different Tanatex products on the moisture absorption of natural/cellulosic fibers and the adhesion on the fibers on main composite matrix will be measured. The effect of Tantex products can optimize the bonding reaction between the resin and the fibers in the (bio) composite and result to improved strength and physico-chemical properties of the biocomposite materials. (word count: 270)
Buildings are responsible for approximately 40% of energy consumption and 36% of carbon dioxide (CO2) emissions in the EU, and the largest energy consumer in Europe (https://ec.europa.eu/energy). Recent research shows that more than 2/3 of all CO2 is emitted during the building process whereas less than 1/3 is emitted during use. Cement is the source of about 8% of the world's CO2 emissions and innovation to create a distributive change in building practices is urgently needed, according to Chatham House report (Lehne et al 2018). Therefore new sustainable materials must be developed to replace concrete and fossil based building materials. Lightweight biobased biocomposites are good candidates for claddings and many other non-bearing building structures. Biocarbon, also commonly known as Biochar, is a high-carbon, fine-grained solid that is produced through pyrolysis processes and currently mainly used for energy. Recently biocarbon has also gained attention for its potential value with in industrial applications such as composites (Giorcellia et al, 2018; Piri et.al, 2018). Addition of biocarbon in the biocomposites is likely to increase the UV-resistance and fire resistance of the materials and decrease hydrophilic nature of composites. Using biocarbon in polymer composites is also interesting because of its relatively low specific weight that will result to lighter composite materials. In this Building Light project the SMEs Torrgas and NPSP will collaborate with and Avans/CoE BBE in a feasibility study on the use of biocarbon in a NPSP biocomposite. The physicochemical properties and moisture absorption of the composites with biocarbon filler will be compared to the biocomposite obtained with the currently used calcium carbonate filler. These novel biocarbon-biocomposites are anticipated to have higher stability and lighter weight, hence resulting to a new, exciting building materials that will create new business opportunities for both of the SME partners.
The climate change and depletion of the world’s raw materials are commonly acknowledged as the biggest societal challenges. Decreasing the energy use and the related use of fossil fuels and fossil based materials is imperative for the future. Currently 40% of the total European energy consumption and about 45% of the CO2 emissions are related to building construction and utilization (EC, 2015). Almost half of this energy is embodied in materials. Developing sustainable materials to find replacement for traditional building materials is therefore an increasingly important issue. Mycelium biocomposites have a high potential to replace the traditional fossil based building materials. Mycelium is the ‘root network’ of mushrooms, which acts as a natural glue to bind biomass. Mycelium grows through the biomass, which functions simultaneously as a growth substrate and a biocomposite matrix. Different organic residual streams such as straw, sawdust or other agricultural waste can be used as substrate, therefore mycelium biocomposites are totally natural, non-toxic, biological materials which can be grown locally and can be composted after usage (Jones et al., 2018). In the “Building On Mycelium” project Avans University of Applied Sciences, HZ University of Applied Sciences, University of Utrecht and the industrial partners will investigate how the locally available organic waste streams can be used to produce mycelium biocomposites with properties, which make them suitable for the building industry. In this project the focus will be on studying the use of the biocomposite as raw materials for the manufacturing of furniture or interior panels (insulation or acoustic).
