The environmental damage arising from the construction and engineering services was responsible for the appearance of several norms and resolutions regulating and directing the sector’s performance. In this article, ...The environmental damage arising from the construction and engineering services was responsible for the appearance of several norms and resolutions regulating and directing the sector’s performance. In this article, we research how professionals with experience in public bids assess the difficulty degree of the implementation of those requirements and how they assess the environmental legislation regarding the protection and conservation of the environment, impact on costs, deadlines and the solution to environmental problems. The results show that industry professionals consider as “high” the level of difficulty to implement the addressed sustainability requirements, and that the Brazilian environmental legislation does not comply with its environmental protection role, increases the possibility of delays and costs of projects and services and hampers the emergence of solutions that could solve environmental problems.展开更多
Height limitations are not uncommon in multi-storey buildings due to economic requirements and esthetical considerations. Substantial spaces are normally required to enable the passage of large pipes and ducts beneath...Height limitations are not uncommon in multi-storey buildings due to economic requirements and esthetical considerations. Substantial spaces are normally required to enable the passage of large pipes and ducts beneath steel beams leading to uneconomic floor heights. The most adopted solution for this issue is the use of steel beam web openings to provide the required space for services. These openings could lead to a significant decrease of the beam load carrying capacity depending on the adopted openings shape, size and location. These aspects motivated the present study based on FE simulations calibrated against numerical and test results. The results accuracy enabled a comprehensive parametric analysis of beams with web openings to be made focused on the profile size, web opening location, among others. The study also investigated the efficiency of longitudinal stiffeners welded at the opening region and benefits of using an adequate edge concordance radius in beams with rectangular and square openings. The obtained results showed the need of using welded longitudinal stiffeners in order to increase the beams ultimate load carrying capacity. This adoption can double or even triple the ultimate load of beams with rectangular and square opening heights equal to 0.75 H, respectively.展开更多
This article analyzes the major stakeholders in the Brazilian construction industry from the viewpoint of the companies in this sector, as well as how these organizations relate to their stakeholders with regard to th...This article analyzes the major stakeholders in the Brazilian construction industry from the viewpoint of the companies in this sector, as well as how these organizations relate to their stakeholders with regard to the topic of sustainability in the construction. The study was based on the principle that the relationship with stakeholders is one of the foundations for the inception and continuity of activities toward sustainability. The findings of which show that the construction companies start the sustainability implementation process without the involvement of external stakeholders. This survey points out the difficulty faced by Brazilian construction companies in relating to their stakeholders. There is the perception that the customers and other actors do not value sustainability-oriented activities, but, at the same time, the relationship of the companies with these stakeholders is limited to disclosure of information. This characteristic of the industry reveals a need for sustainability projects that take into consideration, since their formulation, the stakeholders’ perceptions. The importance of this article lies in the recognition that, although the topic of sustainability is discussed at all levels, studies that examine how specific construction industries have been dealing with it are still rare.展开更多
This study investigates the influence of waste characteristics,especially zeta potential,on the properties of cement pastes and solutions.The focus is to evaluate the impact of the zeta potential of cement particles a...This study investigates the influence of waste characteristics,especially zeta potential,on the properties of cement pastes and solutions.The focus is to evaluate the impact of the zeta potential of cement particles and waste materials on the sedimentation speed,rheology,and hardening time of stabilized cement pastes.Portland Cement II F 40,retarder additive,silica,and fly ash were used in the research.The pastes were prepared,and during the stabilization period,their rheological properties and pH were evaluated.The zeta potential and sedimentation speed of the cement and waste particles were measured at the pH that the pastes presented during the entire stabilization period.After the stabilization period,the pastes were subjected to the hardening time test.The zeta potential analyses revealed diverse values for the different powder types,with the cement particles exhibiting a zeta potential of−3.0 mV,the silica particles exhibiting−10.5 mV,and the fly ash particles exhibiting−20.3 mV.The influence of the high zeta potential modulus was observed on the sedimentation speed,with the solution containing fly ash exhibiting a speed of 40.01μm/s,whereas the solution containing only cement exhibited a speed of 99.38μm/s.In the pastes,the results indicate that the presence of fly ash particles with a significantly negative zeta potential led to a 16%reduction in hardening time compared to particles with a lower modulus of zeta potential.Rheometry tests showed that the inclusion of fly ash particles prevented the formation of agglomerates.Although the zeta potential influenced agglomerate formation and hardening time,it was found to have no effect on yield stress or viscosity.展开更多
文摘The environmental damage arising from the construction and engineering services was responsible for the appearance of several norms and resolutions regulating and directing the sector’s performance. In this article, we research how professionals with experience in public bids assess the difficulty degree of the implementation of those requirements and how they assess the environmental legislation regarding the protection and conservation of the environment, impact on costs, deadlines and the solution to environmental problems. The results show that industry professionals consider as “high” the level of difficulty to implement the addressed sustainability requirements, and that the Brazilian environmental legislation does not comply with its environmental protection role, increases the possibility of delays and costs of projects and services and hampers the emergence of solutions that could solve environmental problems.
文摘Height limitations are not uncommon in multi-storey buildings due to economic requirements and esthetical considerations. Substantial spaces are normally required to enable the passage of large pipes and ducts beneath steel beams leading to uneconomic floor heights. The most adopted solution for this issue is the use of steel beam web openings to provide the required space for services. These openings could lead to a significant decrease of the beam load carrying capacity depending on the adopted openings shape, size and location. These aspects motivated the present study based on FE simulations calibrated against numerical and test results. The results accuracy enabled a comprehensive parametric analysis of beams with web openings to be made focused on the profile size, web opening location, among others. The study also investigated the efficiency of longitudinal stiffeners welded at the opening region and benefits of using an adequate edge concordance radius in beams with rectangular and square openings. The obtained results showed the need of using welded longitudinal stiffeners in order to increase the beams ultimate load carrying capacity. This adoption can double or even triple the ultimate load of beams with rectangular and square opening heights equal to 0.75 H, respectively.
文摘This article analyzes the major stakeholders in the Brazilian construction industry from the viewpoint of the companies in this sector, as well as how these organizations relate to their stakeholders with regard to the topic of sustainability in the construction. The study was based on the principle that the relationship with stakeholders is one of the foundations for the inception and continuity of activities toward sustainability. The findings of which show that the construction companies start the sustainability implementation process without the involvement of external stakeholders. This survey points out the difficulty faced by Brazilian construction companies in relating to their stakeholders. There is the perception that the customers and other actors do not value sustainability-oriented activities, but, at the same time, the relationship of the companies with these stakeholders is limited to disclosure of information. This characteristic of the industry reveals a need for sustainability projects that take into consideration, since their formulation, the stakeholders’ perceptions. The importance of this article lies in the recognition that, although the topic of sustainability is discussed at all levels, studies that examine how specific construction industries have been dealing with it are still rare.
文摘This study investigates the influence of waste characteristics,especially zeta potential,on the properties of cement pastes and solutions.The focus is to evaluate the impact of the zeta potential of cement particles and waste materials on the sedimentation speed,rheology,and hardening time of stabilized cement pastes.Portland Cement II F 40,retarder additive,silica,and fly ash were used in the research.The pastes were prepared,and during the stabilization period,their rheological properties and pH were evaluated.The zeta potential and sedimentation speed of the cement and waste particles were measured at the pH that the pastes presented during the entire stabilization period.After the stabilization period,the pastes were subjected to the hardening time test.The zeta potential analyses revealed diverse values for the different powder types,with the cement particles exhibiting a zeta potential of−3.0 mV,the silica particles exhibiting−10.5 mV,and the fly ash particles exhibiting−20.3 mV.The influence of the high zeta potential modulus was observed on the sedimentation speed,with the solution containing fly ash exhibiting a speed of 40.01μm/s,whereas the solution containing only cement exhibited a speed of 99.38μm/s.In the pastes,the results indicate that the presence of fly ash particles with a significantly negative zeta potential led to a 16%reduction in hardening time compared to particles with a lower modulus of zeta potential.Rheometry tests showed that the inclusion of fly ash particles prevented the formation of agglomerates.Although the zeta potential influenced agglomerate formation and hardening time,it was found to have no effect on yield stress or viscosity.
