60 research outputs found
The effect of fibres and carbonation conditions on the mechanical properties and microstructure of lime/flax composites
Fibre and textile-reinforced mortars are increasingly being used for a variety of building applications, including the strengthening of masonry structures. Lime mortars reinforced with sustainable fibres (such as vegetable or cellulosic fibres) may provide an interesting solution. In this paper, a mixture of commercial lime with 20% metakaolin addition was used to produce composites reinforced with non-woven flax fabrics that were cured at different moisture contents (from 0 to 100%) for 7 or 14 days in a CO2 incubator. The composites were char- acterised to determine their flexural behaviour, carbonation level and microstructure. According to the results, no differences exist in the flexural strength of the composites made in the moisture range of 33%–66%. At 7 days of curing, they attained Modulus of Rupture (MOR) values that exceeded 5.5. MPa. Moreover, it was observed that under high moisture conditions, the permeability of the fibres allows for CO2 access, despite the saturation of the pores of the matrix – allowing a reaction in the vicinity of the fibres –, while under dry conditions, the fibre’s moisture retention does not permit the carbonation of the matrix in their vicinity, even though complete carbonation takes place after 14 daysPostprint (published version
A Combined Fuzzy Logic and Analytical Hierarchy Process Method for Optimal Selection and Locating of Pedestrian Crosswalks
One of the main challenges for transportation engineers is the consideration of pedestrian safety as the most vulnerable aspect of the transport system. In many countries around the world, a large number of accidents recorded by the police are composed of accidents involving pedestrians and vehicles, for example when pedestrians may be struck by passing vehicles when crossing the street. Careful consideration of the parameters that are involved in selecting the type and optimum location of pedestrian crosswalks results in a higher pedestrian safety coefficient and a reduced accident rate at these facilities. At the start of this study, these parameters that are important in specifying the optimum type and location of pedestrian crosswalks were determined. Then the data layers of these identified parameters were defined using the ArcGIS software. These layers can subsequently be used for determination of the optimal positioning of pedestrian crosswalks. To specify the boundary changes for each parameter, fuzzy membership functions were defined for each parameter using fuzzy logic. The Analytical Hierarchy Process method (AHP) was used in order to combine these layers of information after the fuzzy membership functions were defined. Expert Choice software was used to determine the final weight resultant of the professionals' poll that was conducted. A field study sample has been carried out to determine the optimal location of pedestrian crosswalks in the city of Tehran. The final output from the ArcGIS software shows the ideal locations and the appropriate type of pedestrian crosswalks in the field study sample. The results indicate that the use of fuzzy logic in definition of membership functions of location parameters, along with using AHP for determination of the weight of data layers built in ArcGIS, is a satisfactory combined method for specifying the location of pedestrian crosswalks
Serviceability parameters and social sustainability assessment of flax fabric reinforced lime-based drywall interior panels
In the search of more environmentally-friendly construction materials, the use of natural-based fibers has gained much attention as reinforcement in the inorganic-based matrix. In this paper, the nonwoven flax fabric reinforced lime composites are created using a dewatering technique, and the serviceability parameters –thermal conductivity, sound absorption coefficient, and residual flexural resistance after exposure to elevated temperature– are determined experimentally. The tests are carried out on two different lime composites prepared under two distinct curing regimens, i.e., accelerated carbonation in a CO2 chamber and natural carbonation in laboratory conditions, to evaluate the effect of forced carbonation. In addition, the experimental results of the serviceability parameters are included in the MIVES model (Integrated Value Model for Sustainability Assessment) to evaluate the social sustainability of the developed material as an interior drywall panel. MIVES, a type of multi-criteria decision-making method, is based on the value function concept and seminars with experts. According to the results of experimental tests, the accelerated cured sample has higher thermal conductivity (~4 times) and lower sound absorption coefficients (~20%) than the naturally cured one. Nonetheless, the flexural performance of the former is 50% (at room temperature) and 100% (at elevated temperature) better. As for the social sustainability index assessed by the MIVES-based multi-objective approach, it ranges between 0.65 and 0.75 (out of 1.0) for both lime composite panels, at least 20% higher than the control lime panel with no reinforcement. The sustainability model designed for this research can be used for assessing the social sustainability performance of other materials although the weights assigned by the experts could be adapted to reflect the perceptions and local preferences.This work was supported through the project grants PID2019-108067RB-I00/AEI/10.13039/501100011033 and PID2020-117530RB-I00/MCIN/AEI/10.13039/501100011033 by the Ministerio de Ciencia e Innovación (MCIN)/Agencia Estatal de Investigación (AEI) of the Spanish Government. The author Payam Sadrolodabaee acknowledges the Banco Santander for the Research Scholarships (Postdoc-UPC 2022 Grant).Peer ReviewedObjectius de Desenvolupament Sostenible::12 - Producció i Consum ResponsablesPostprint (published version
Introduction to advances in construction and demolition waste
Resource efficiency, as well as the importance and limitations of the Circular economy concept, are highlighted. The case of construction and demolition waste-CDW recycling is introduced. The 70% recycling rate for EU in 2020 is analyzed and a literature review on the Waste Framework Directive is carried out. Brief comments on CDW containing hazardous substances are made. A book outline is included
Exploring indicators of circular economy adoption framework through a hybrid decision support approach
Circular economy (CE) focuses on a circular approach to energy and material resources, which provides economic, environmental and social benefits for manufacturing organisations. CE adoption in emerging economies facilitates in substantial economic growth through appropriate utilisation of energy and material resources across manufacturing industries. This study identifies CE indicators in the context of an emerging economy. The study further develops a framework for the adoption of CE and tests it through a hybrid Best Worst Method and Decision-Making Trial and Evaluation Laboratory approach. The framework is validated through an Indian manufacturing case organisation. While Best Worst Method computes the CE related indicator weights, Decision-Making Trial and Evaluation Laboratory analyses the inter-relationship among indicators. Disparate CE related indicators, e.g. strategic, managerial, informational and technological, supply chain and organisational, influence the CE adoption in an emerging economy context. The findings reveal that the strategic and managerial indicators have the strongest influence on developing other indicators. The causal digraph and relationship diagram assist the practitioners in predicting the inter-relationship of indicators in CE adoption. The study outcomes will help the practitioners, policymakers and researchers to draw a framework for adoption of circular and green practices and usage of resources sustainably
Evaluating the effect of traffic assignment method on the accuracy of origin-destination matrix correction results in traffic fuzzy flow method
Q‌U‌A‌N‌T‌I‌F‌I‌C‌A‌T‌I‌O‌N O‌F C‌O‌N‌S‌T‌R‌U‌C‌T‌I‌O‌N W‌A‌S‌T‌E P‌R‌O‌D‌U‌C‌T‌I‌O‌N O‌F B‌U‌L‌K M‌A‌T‌E‌R‌I‌A‌L‌S (C‌A‌S‌E S‌T‌U‌D‌Y: R‌E‌S‌I‌D‌E‌N‌T‌I‌A‌L B‌U‌I‌L‌D‌I‌N‌G‌S I‌N T‌E‌H‌R‌A‌N)
N‌o‌w‌a‌d‌a‌y‌s, m‌a‌s‌s p‌r‌o‌d‌u‌c‌t‌i‌o‌n o‌f c‌o‌n‌s‌t‌r‌u‌c‌t‌i‌o‌n w‌a‌s‌t‌e i‌s o‌n‌e o‌f t‌h‌e m‌o‌s‌t i‌m‌p‌o‌r‌t‌a‌n‌t e‌n‌v‌i‌r‌o‌n‌m‌e‌n‌t‌a‌l i‌s‌s‌u‌e‌s. C‌o‌n‌s‌t‌r‌u‌c‌t‌i‌o‌n i‌n‌d‌u‌s‌t‌r‌y c‌o‌n‌s‌u‌m‌e‌s a l‌a‌r‌g‌e a‌m‌o‌u‌n‌t o‌f m‌a‌t‌e‌r‌i‌a‌l‌s a‌n‌d r‌e‌s‌o‌u‌r‌c‌e‌s, e‌s‌p‌e‌c‌i‌a‌l‌l‌y i‌n d‌e‌v‌e‌l‌o‌p‌i‌n‌g c‌o‌u‌n‌t‌r‌i‌e‌s. I‌n‌e‌f‌f‌i‌c‌i‌e‌n‌t u‌s‌a‌g‌e o‌f b‌u‌l‌k m‌a‌t‌e‌r‌i‌a‌l‌s r‌e‌s‌u‌l‌t‌s i‌n p‌r‌o‌d‌u‌c‌t‌i‌o‌n o‌f c‌o‌n‌s‌t‌r‌u‌c‌t‌i‌o‌n w‌a‌s‌t‌e. A‌c‌c‌o‌r‌d‌i‌n‌g t‌o s‌u‌s‌t‌a‌i‌n‌a‌b‌l‌e d‌e‌v‌e‌l‌o‌p‌m‌e‌n‌t g‌u‌i‌d‌e‌l‌i‌n‌e‌s, m‌a‌s‌s p‌r‌o‌d‌u‌c‌t‌i‌o‌n o‌f c‌o‌n‌s‌t‌r‌u‌c‌t‌i‌o‌n w‌a‌s‌t‌e i‌s o‌n‌e o‌f t‌h‌e i‌s‌s‌u‌e‌s o‌f f‌o‌c‌u‌s‌e‌d c‌o‌n‌c‌e‌r‌n. I‌n I‌r‌a‌n, t‌h‌e‌r‌e i‌s n‌o c‌l‌e‌a‌r r‌e‌c‌o‌r‌d o‌r v‌a‌l‌i‌d d‌a‌t‌a a‌b‌o‌u‌t d‌i‌f‌f‌e‌r‌e‌n‌t a‌s‌p‌e‌c‌t‌s o‌f c‌o‌n‌s‌t‌r‌u‌c‌t‌i‌o‌n w‌a‌s‌t‌e p‌r‌o‌d‌u‌c‌t‌i‌o‌n. Q‌u‌a‌n‌t‌i‌f‌i‌c‌a‌t‌i‌o‌n o‌f t‌h‌e c‌o‌n‌s‌t‌r‌u‌c‌t‌i‌o‌n w‌a‌s‌t‌e p‌r‌o‌d‌u‌c‌t‌i‌o‌n i‌s o‌n‌e o‌f t‌h‌e n‌e‌w c‌o‌n‌c‌e‌p‌t‌s i‌n w‌a‌s‌t‌e m‌a‌n‌a‌g‌e‌m‌e‌n‌t. T‌h‌e‌r‌e‌f‌o‌r‌e, t‌h‌e a‌i‌m o‌f t‌h‌i‌s r‌e‌s‌e‌a‌r‌c‌h i‌s t‌o q‌u‌a‌n‌t‌i‌f‌y c‌o‌n‌s‌t‌r‌u‌c‌t‌i‌o‌n w‌a‌s‌t‌e p‌r‌o‌d‌u‌c‌t‌i‌o‌n o‌f b‌u‌l‌k m‌a‌t‌e‌r‌i‌a‌l‌s i‌n r‌e‌s‌i‌d‌e‌n‌t‌i‌a‌l b‌u‌i‌l‌d‌i‌n‌g‌s. T‌h‌e f‌o‌c‌u‌s o‌f t‌h‌i‌s s‌t‌u‌d‌y i‌s o‌n r‌e‌b‌a‌r, c‌o‌n‌c‌r‌e‌t‌e, b‌r‌i‌c‌k, a‌n‌d c‌e‌m‌e‌n‌t w‌a‌s‌t‌e p‌r‌o‌d‌u‌c‌e‌d i‌n t‌h‌e b‌u‌i‌l‌d‌i‌n‌g‌s.T‌h‌e u‌r‌b‌a‌n d‌e‌v‌e‌l‌o‌p‌e‌r‌s m‌a‌y u‌t‌i‌l‌i‌z‌e t‌h‌e r‌e‌s‌u‌l‌t‌s t‌o r‌e‌g‌u‌l‌a‌t‌e m‌o‌r‌e d‌e‌t‌a‌i‌l‌e‌d a‌n‌d p‌r‌e‌c‌i‌s‌e r‌u‌l‌e‌s t‌o c‌o‌n‌t‌r‌o‌l t‌h‌e p‌r‌o‌d‌u‌c‌t‌i‌o‌n o‌f c‌o‌n‌s‌t‌r‌u‌c‌t‌i‌o‌n w‌a‌s‌t‌e. T‌h‌e d‌e‌p‌e‌n‌d‌e‌n‌t v‌a‌r‌i‌a‌b‌l‌e o‌f t‌h‌e s‌t‌u‌d‌y i‌s t‌h‌e a‌m‌o‌u‌n‌t o‌f w‌a‌s‌t‌e p‌r‌o‌d‌u‌c‌e‌d f‌o‌r e‌v‌e‌r‌y t‌y‌p‌e o‌f m‌a‌t‌e‌r‌i‌a‌l i‌n p‌e‌r‌c‌e‌n‌t. T‌h‌e i‌n‌d‌e‌p‌e‌n‌d‌e‌n‌t v‌a‌r‌i‌a‌b‌l‌e‌s o‌f t‌h‌e s‌t‌u‌d‌y a‌r‌e l‌o‌c‌a‌t‌i‌o‌n o‌f r‌e‌s‌i‌d‌e‌n‌t‌i‌a‌l b‌u‌i‌l‌d‌i‌n‌g‌s, t‌y‌p‌e o‌f c‌o‌n‌t‌r‌a‌c‌t, a‌r‌e‌a o‌f e‌v‌e‌r‌y s‌t‌o‌r‌y, a‌n‌d n‌u‌m‌b‌e‌r o‌f s‌t‌o‌r‌i‌e‌s i‌n e‌v‌e‌r‌y r‌e‌s‌i‌d‌e‌n‌t‌i‌a‌l b‌u‌i‌l‌d‌i‌n‌g. F‌u‌r‌t‌h‌e‌r‌m‌o‌r‌e, t‌w‌o f‌r‌e‌q‌u‌e‌n‌t t‌y‌p‌e‌s o‌f c‌o‌n‌t‌r‌a‌c‌t‌s f‌o‌r r‌e‌s‌i‌d‌e‌n‌t‌i‌a‌l b‌u‌i‌l‌d‌i‌n‌g‌s c‌o‌s‌t-p‌l‌u‌s a‌n‌d l‌u‌m‌p-s‌u‌m c‌o‌n‌t‌r‌a‌c‌t‌s a‌r‌e i‌n‌v‌e‌s‌t‌i‌g‌a‌t‌e‌d. O‌b‌t‌a‌i‌n‌e‌d d‌a‌t‌a i‌s a‌n‌a‌l‌y‌z‌e‌d b‌y S‌P‌S‌S s‌o‌f‌t‌w‌a‌r‌e u‌s‌i‌n‌g l‌i‌n‌e‌a‌r r‌e‌g‌r‌e‌s‌s‌i‌o‌n, a‌n‌d t‌h‌e‌n a‌r‌e v‌e‌r‌i‌f‌i‌e‌d a‌n‌d v‌a‌l‌i‌d‌a‌t‌e‌d t‌o e‌x‌t‌r‌a‌c‌t t‌h‌e b‌e‌s‌t a‌n‌d m‌o‌s‌t c‌o‌n‌v‌e‌n‌i‌e‌n‌t r‌e‌g‌r‌e‌s‌s‌i‌o‌n‌s. T‌h‌e c‌r‌i‌t‌e‌r‌i‌a f‌o‌r v‌a‌l‌i‌d‌a‌t‌i‌o‌n a‌n‌d v‌e‌r‌i‌f‌i‌c‌a‌t‌i‌o‌n o‌f t‌h‌e q‌u‌a‌n‌t‌i‌t‌a‌t‌i‌v‌e e‌q‌u‌a‌t‌i‌o‌n‌s a‌r‌e d‌e‌r‌i‌v‌e‌d f‌r‌o‌m s‌t‌a‌t‌i‌s‌t‌i‌c‌a‌l r‌e‌f‌e‌r‌e‌n‌c‌e‌s a‌n‌d t‌h‌e m‌o‌s‌t r‌e‌c‌e‌n‌t a‌n‌d r‌e‌l‌a‌t‌e‌d s‌t‌u‌d‌i‌e‌s. T‌h‌e r‌e‌s‌u‌l‌t i‌s f‌o‌u‌r v‌a‌l‌i‌d a‌n‌d v‌e‌r‌i‌f‌i‌e‌d q‌u‌a‌n‌t‌i‌t‌a‌t‌i‌v‌e m‌o‌d‌e‌l‌s d‌e‌s‌c‌r‌i‌b‌i‌n‌g t‌h‌e a‌m‌o‌u‌n‌t o‌f w‌a‌s‌t‌e m‌a‌t‌e‌r‌i‌a‌l‌s p‌r‌o‌d‌u‌c‌e‌d i‌n t‌e‌r‌m‌s o‌f i‌n‌d‌e‌p‌e‌n‌d‌e‌n‌t v‌a‌r‌i‌a‌b‌l‌e‌s. R‌e‌s‌u‌l‌t‌s s‌h‌o‌w t‌h‌a‌t c‌h‌o‌o‌s‌i‌n‌g c‌o‌s‌t-p‌l‌u‌s c‌o‌n‌t‌r‌a‌c‌t l‌e‌a‌d‌s t‌o m‌o‌r‌e c‌o‌n‌s‌t‌r‌u‌c‌t‌i‌o‌n w‌a‌s‌t‌e p‌r‌o‌d‌u‌c‌t‌i‌o‌n t‌h‌a‌n l‌u‌m‌p-s‌u‌m c‌o‌n‌t‌r‌a‌c‌t. T‌h‌e p‌o‌s‌i‌t‌i‌v‌e a‌n‌d n‌e‌g‌a‌t‌i‌v‌e e‌f‌f‌e‌c‌t‌s o‌f o‌t‌h‌e‌r d‌e‌p‌e‌n‌d‌e‌n‌t v‌a‌r‌i‌a‌b‌l‌e‌s, s‌u‌c‌h a‌s l‌o‌c‌a‌t‌i‌o‌n, n‌u‌m‌b‌e‌r o‌f s‌t‌o‌r‌i‌e‌s, o‌r a‌r‌e‌a o‌f e‌a‌c‌h s‌t‌o‌r‌y a‌r‌e d‌e‌t‌e‌r‌m‌i‌n‌e‌d t‌o‌o
Application of structure equation models in trip behavior analysis of Tehran Bazar trip makers
Investigating the role of latent individual components in the acceptance of demand management policies: Case study of Tehran odd-even policy
Due to the problems caused by personal car use, demand management policies have been developed, which result in reduced use of personal vehicles. It is generally accepted that demand management policies are classified into two types: hard or soft. In the case of soft politics, people tend to be receptive, while being combative to hard policies. In the case of Tehran's odd or even zone, the purpose of the paper is to examine the role of latent components in the acceptance of demand management policies. To address the issue and measure the resistance of individuals to accept the car reduction policy, we designed a stated preference questionnaire and measured the acceptance rate in terms of behavior change. Changes in behavior patterns and the choice of private car mode are methods used to determine acceptance rates. The acceptance of policies can be assessed by identifying their hidden nature via the value-belief-norm theory. In this theory, value influences the norm through belief. So, people who know that they should cut down on the use of the private car are more inclined to accept the use of private cars. Examination of the adoption of private car prohibiting policies under changing behavior in different periods of implementation of a private car is debatable. In this study, more than 500 questionnaires were distributed randomly among Tehran citizens including couples or single individuals considering the scope of the traffic plan traveled by transit vehicles. Using the multiple logit model, this study investigates the changes in people's behavior toward accepting the policies of reducing the use of private cars in two short-term and long-term periods. Results show that individual values and norms are effective factors in changing users' behavior over short- and long-term periods
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