This research investigated the use of wood ash to partially replace cement or sand in conventional concrete, roller compacted concrete (RCC), and flowable fill. The main focus was to determine how the wood ash additio...This research investigated the use of wood ash to partially replace cement or sand in conventional concrete, roller compacted concrete (RCC), and flowable fill. The main focus was to determine how the wood ash addition affected the main fresh and hardened properties of these materials. It was found that the wood ash could be successfully incorporated into the conventional concrete. In particular, the wood ash addition not only accelerated the setting, but also improved the early and the 28-day compressive strength of concrete that contained the blast furnace slag. It was also observed that the wood ash could be positively added into RCC to facilitate the compaction and reduce the risk of segregation. In addition, the wood ash can be beneficially introduced into the flowable fill mixtures to facilitate flow, to alleviate bleeding and subsidence, as well as to achieve controlled strength especially when combined with the class C or the class F fly ash.展开更多
The research object was high 120 m concrete gravity dam of the Angara Bratsk hydroelectric power plant. The state of the concrete dam is estimated based on the results of continuous supervision performed by site perso...The research object was high 120 m concrete gravity dam of the Angara Bratsk hydroelectric power plant. The state of the concrete dam is estimated based on the results of continuous supervision performed by site personnel as well as periodic monitoring. According to the classification of the interrelations in the system ＂concrete-environment＂, there were selected some important parts of dams and a comprehensive analysis of concrete was executed on these parts. Concerning the complex research of concrete, a combination of full-scale tests with core-sampling has been proposed. Core samples tests had an object to study the deep concrete layers and to determine the specific indicators such as strength, density, porosity, comparative diameter of capillary pores, CaO content in cement stone and others. Obtained findings and recommended criteria can be applied when selecting technologies for constructing dams that guarantee their durability in the north.展开更多
The present research aims to identify the possibilities of rehabilitation of building facades in the centre of Chisinau, through the use of high-performance materials, use of high-performance technologies in exec...The present research aims to identify the possibilities of rehabilitation of building facades in the centre of Chisinau, through the use of high-performance materials, use of high-performance technologies in execution, reduction of facade renovation costs, etc. In the process of organising the rehabilitation works of historical buildings of architectural value, we are dealing with the following: the value of the rehabilitation works of a historical building is very high, the duration of the rehabilitation is important, the attitude of the society is insufficient, the lack of strategies for the rehabilitation of buildings at the municipality level. In order to achieve this objective, we propose to research the following tasks: definition of the concept of rehabilitation of buildings in the Historic Centre of Chisinau;legislative, normative assurance of rehabilitation of historical heritage in the Republic of Moldova;analysis of the situation in Chisinau on the example of historical buildings with limestone finishes and examination by non-destructive methods of facades;solutions for rehabilitation of facades of historical buildings by comparing two types of technologies. In conclusion, emphasis will be placed on the choice of the most efficient method in terms of material, technology and cost.展开更多
The construction industry is a major contributor to environmental pollution.The effect of the construction industry on the environment may be mitigated using eco-friendly construction materials,such as biocomposites.O...The construction industry is a major contributor to environmental pollution.The effect of the construction industry on the environment may be mitigated using eco-friendly construction materials,such as biocomposites.Once developed,biocomposites may offer a viable alternative to the current materials in use.However,biocomposites are lagging in terms of adoption and eventual use in the construction industry.This article provides insights into the steps for biocomposites to become a product that is ready to use by the construction industry in a structural role.The development and the adoption of such a material is tackled with the use of two concepts,i.e.,technology readiness level and roadmapping,and explored in a case study on the“liquid wood”.Furthermore,interviews in the construction industry are carried out to identify the industry’s take on biocomposites.A customized roadmap,which underlines a mostly nontechnical perspective concerning this material,has emerged.Additionally,the adoption and diffusion issues that the“liquid wood”may encounter are outlined and complemented with further recommendations.展开更多
文摘This research investigated the use of wood ash to partially replace cement or sand in conventional concrete, roller compacted concrete (RCC), and flowable fill. The main focus was to determine how the wood ash addition affected the main fresh and hardened properties of these materials. It was found that the wood ash could be successfully incorporated into the conventional concrete. In particular, the wood ash addition not only accelerated the setting, but also improved the early and the 28-day compressive strength of concrete that contained the blast furnace slag. It was also observed that the wood ash could be positively added into RCC to facilitate the compaction and reduce the risk of segregation. In addition, the wood ash can be beneficially introduced into the flowable fill mixtures to facilitate flow, to alleviate bleeding and subsidence, as well as to achieve controlled strength especially when combined with the class C or the class F fly ash.
文摘The research object was high 120 m concrete gravity dam of the Angara Bratsk hydroelectric power plant. The state of the concrete dam is estimated based on the results of continuous supervision performed by site personnel as well as periodic monitoring. According to the classification of the interrelations in the system ＂concrete-environment＂, there were selected some important parts of dams and a comprehensive analysis of concrete was executed on these parts. Concerning the complex research of concrete, a combination of full-scale tests with core-sampling has been proposed. Core samples tests had an object to study the deep concrete layers and to determine the specific indicators such as strength, density, porosity, comparative diameter of capillary pores, CaO content in cement stone and others. Obtained findings and recommended criteria can be applied when selecting technologies for constructing dams that guarantee their durability in the north.
文摘The present research aims to identify the possibilities of rehabilitation of building facades in the centre of Chisinau, through the use of high-performance materials, use of high-performance technologies in execution, reduction of facade renovation costs, etc. In the process of organising the rehabilitation works of historical buildings of architectural value, we are dealing with the following: the value of the rehabilitation works of a historical building is very high, the duration of the rehabilitation is important, the attitude of the society is insufficient, the lack of strategies for the rehabilitation of buildings at the municipality level. In order to achieve this objective, we propose to research the following tasks: definition of the concept of rehabilitation of buildings in the Historic Centre of Chisinau;legislative, normative assurance of rehabilitation of historical heritage in the Republic of Moldova;analysis of the situation in Chisinau on the example of historical buildings with limestone finishes and examination by non-destructive methods of facades;solutions for rehabilitation of facades of historical buildings by comparing two types of technologies. In conclusion, emphasis will be placed on the choice of the most efficient method in terms of material, technology and cost.
文摘The construction industry is a major contributor to environmental pollution.The effect of the construction industry on the environment may be mitigated using eco-friendly construction materials,such as biocomposites.Once developed,biocomposites may offer a viable alternative to the current materials in use.However,biocomposites are lagging in terms of adoption and eventual use in the construction industry.This article provides insights into the steps for biocomposites to become a product that is ready to use by the construction industry in a structural role.The development and the adoption of such a material is tackled with the use of two concepts,i.e.,technology readiness level and roadmapping,and explored in a case study on the“liquid wood”.Furthermore,interviews in the construction industry are carried out to identify the industry’s take on biocomposites.A customized roadmap,which underlines a mostly nontechnical perspective concerning this material,has emerged.Additionally,the adoption and diffusion issues that the“liquid wood”may encounter are outlined and complemented with further recommendations.
