Browse

The development and testing of advanced materials for the protection and repair of concrete structures is the main objective of the presented research. Two types of synthetic resins have been developed, applied to concrete samples and their effectiveness in improving the durability of the samples investigated has been tested. Type A is an epoxy resin with non-reactive solvents, originally designed for thin-layer surface treatment to achieve a highly closed and cross-linked surface. Type 50 is a modified low-viscos...

In a view of the sustainable development principles, the development of advanced lowcarbon building materials represents one of the most important issues in the construction industry. To follow the current trends in research and development of building materials, special attention is paid to the reuse of all kinds of waste and industrial byproducts. One of the serious problems of today-s society is the huge production of sewage sludge from waste water treatment and its disposal. As one of the promising ways of sew...

Properties of building materials include many properties, the most important are mechanical, thermal, chemical, and economic. The most important thermal properties that characterize the total heat losses and thermal inertia of materials are thermal conductivity and specific heat capacity. The first one describes the stationary heat transfer through the structures, but the second describes the ability to absorb and release the heat energy with temperature change dynamically, and it is related to a unit mass of the ...

Among the newest and best performing metallic materials are high-entropy alloys, which is why more than five thousand articles related to them have been published in the last decade. However, there are few articles that refer to the brazing behavior of new types of metallic materials. In this publication, the brazed joint between two biocompatible alloy components from the MoNbTaTiZrW0.2 system were performed using an ecological Cu-Ag-Zn alloy as filler material. The optical and SEM microscopy analyzes were perfor...

Europe must avoid losing manufacturing SMEs. However, presenting distinct maturity levels, these companies have a hard time fulfilling the necessary ecological sustainability level. Controversially, despite the intense debate about digital technologies, there is still a need for knowledge in the industrial world about the impact of these technologies to make manufacturing SMEs environmentally friendly. According to data made available by Stone Portuguese Federation, in 2019, the Portuguese Ornamental Stone sector ...

Increasing demands on the thermal performance of the building envelope play a crucial role in the design of buildings in order to maintain a quality indoor climate with reduced energy consumption. In case of repair mortars development, the necessary thermal insulation improvement can be effectively achieved by using lightweight aggregates. However, the application of new materials to historical buildings might be problematic due to their incompatibility with materials originally used in the past. In this paper, tw...

The article aims to design optimized synergistic structures between additive materials from the category of industrial by-products, by applying experimental modeling, in order to achieve increase of performance parameters for the final products, in line with the needs of the building materials market and challenges to develop lower-carbon alternatives for reducing the climate impacts of the built environment. The experimental applications based on the integration of industrial by-products will results in defining ...

Vacuum insulation panels (VIP) represent a group of super-insulation materials that make it possible to significantly reduce the energy consumption of building structures even in places where it is not possible to build in a greater thickness of insulation. Considering that the consumption of these insulators worldwide is increasing every year, it is necessary to look for long-term sustainable raw material sources, such as easy renewable raw sources. The contribution is devoted to the possibilities of using easy r...

Recently, nanotechnology has attracted a considerable scientific interest due the potential new uses of non-particles, which can improve the properties of cement mortars or concretes, such as Nanosilica. Nanoparticles, like those of nanosilica, have been shown to have unique physical and chemical properties different from those of conventional cement additions. Nanosilica was used either to replace part of the cements or as an addition to improve the performance of the cement such as accelerating the hydration of ...

The use of secondary waste from municipal solid waste incineration plant in concrete has been studied for its potential to reduce the carbon footprint and abiotic depletion associated with traditional concrete production. Fly ash is a hazardous waste and it can be used as a substitute for cement in the production of concrete. Bottom ash can be used as a substitute for light natural aggregate, which was previously soaked in water for internal treatment of concrete. The composition of concrete includes: CEM I 42.5R,...

This research aims to contribute to the development of eco-friendly car seats using hanji yarn by examining the flame-retardant treatment effect of two types of hanji yarn fabrics woven with polyester warp yarn and two different types of weft yarn: hanji- polyester blended yarn (76:24) and 100-percent hanji yarn, respectively. In terms of the flame-retardant treatment, NICCA FI-NONE PD-38 was used as the flame retardant with the concentrations of 10, 20, and 30 percent, and a flame resistance test was conducted in...

In view of the growing population and urbanization, it is necessary to ensure the development of advanced building materials capable of ensuring the quality of living conditions with as low energy consumption as possible. A proven way to achieve this is to create a composite material with a lightweight aggregate. However, the use of lightweight aggregate could also affect other material properties, such as mechanical strength or water absorption. In this study, the silica sand aggregate was partially and completel...

A case study for a public library which aim to become nearly Zero Energy Building (nZEB) is presented. Due to building-s location in the city center of a medium sized municipality from Romania, important site limits have to be considered, as well as other pre-existent conditions. These conditions significantly limit the technological options that can be implemented to ensure nZEB compliance. Also, the destination itself of the building (library with free access to the shelves), imposes a specific energy profile (c...

With the rapid growth of the population and urbanization, the demand for industrial production has continued to increase, and industrial solid waste has become more and more abundant. Industrial solid waste mainly includes fly ashes, slags, tailings, red mud, bottom ashes and other wastes, which account for approximately 80% of the total waste produced on Earth. Industrial wastes generally contain various heavy metal components such as Pb, Zn, Cu, Cd, Cr, As, Ba and Mn. The low recycling rate of solid waste result...

A novel composite matrix composed of Portland cement (PC) and municipal solid waste incineration ash (MSWIA) was developed for the simultaneous immobilization of three heavy metals - Ba, Pb and Zn. The main motivation for the research was to exploit and reuse MSWIA to design alternative composite matrix with the ability to immobilize hazardous pollutants, such as heavy metals, which might be used as filler for the cement-based construction materials. In composition of prepared composite matrix, MSWIA was used as a...

This paper is structured in two directions. The first one presents issues related to technical losses within a construction project. The second one analyzes the integration of technical losses resulting from building materials in a circular economy, as they occur from 2 projects. Each project assesses costs and specific situations for each type of material based on the profile of each presented project. Benefits of technical losses management from building materials and waste are identified as they can be engaged ...

The process of selecting and prioritizing investment project proposals in construction is characterized by multiple objectives and uncertainties due to incomplete information and the multitude and dynamics of factors that can intervene. Knowing their significance and influence on the final investment decision, it is a complex problem that requires a multi-critical analysis with both quantitative and qualitative factors, necessary for a good quantification and evaluation. In recent years, the increase in the comple...

The incorporation of natural fibres as reinforcement of concrete is attractive from a sustainable perspective. In fact, natural fibres improve the deformation capacity and increase the ductility of concrete. In addition, natural fibres are lightweight, renewable, less expensive than man-made fibres and locally abundant. However, in order to determine their use in different concrete applications, it is necessary to know the impact on the mechanical properties and the benefits that can be obtained by incorporating t...

This paper focuses on the experimental testing of hydrated lime-, natural hydraulic lime-, and lime-cement-based mortars with improved salt accumulation capacity. Moreover, the effect of varying content of non-hydrophobised expanded perlite (EP) in the mortars on their durability was investigated. The substation of silica sand by expanded perlite was 25%, 50%, 75% and 100% by volume. A modified method based on the adsorption of free salt ions from solution was used to measure the chloride binding isotherms. The sa...

The paper contains the results of experimental research on the elaboration of the composition and optimization of the properties of the self-levelling screed based on cement and sand, intended for the fulfilment of the intermediate layer of floors, including industrial enterprises with the aggressive environment; sedentary parts of tanks, basins; bunkers; different containers, etc. The reinforced self-levelling screed has an absolutely horizontal surface. It allows the application of finished layers of composite p...

Environmental pollution from polymer waste is one of the severe ecological problems. As of today, each day, approximately eight million pieces of plastic waste reach the ocean, where they are transformed into microplastics (small particles). Organisms in the sea are eating microplastics. The harmful effects of garbage ultimately affect humans. Due to the magnitude of the problem, the demand for biodegradable, eco-friendly materials, which will decompose after the operational period and will not pollute the environ...

Green building materials are gaining attention for achieving carbon neutrality in civil engineering. To reduce CO2 emissions from cement, using low-cement or cement-free materials with local supplementary cementitious materials (SCMs) is promising. Blended cements with SCMs enhance long-term strength, but low-clinker blends often have low early strength. To address this, understanding the hydration of ordinary Portland cement is crucial. While C3S has been studied, the role of C3A, the most reactive component of c...

In this study, magnesium oxychloride cement (MOC) mortars reinforced with multiwalled carbon nanotubes (MWCNT) and graphene were prepared and analyzed. The lower CO2 footprint of MOC in comparison with the production of ordinary Portland cement (OPC) predestines MOC-based materials to be an environmentally sustainable alternative to OPC. However, the wider spread of MOC is hindered by its low water resistance. The combined influence of MWCNT and graphene as 1D and 2D carbon nanomaterials on properties of MOC morta...

With the development of concrete technology, the polypropylene fibers have been extensively used in concrete structures for property and durability enhancement. The polypropylene fibers have significantly low cost compared to steel, the use of macro polypropylene fiber could achieve a similar level of reinforcement in concrete at a half price of using steel. The article focuses on the influence of polypropylene fibres of concrete properities. The aim is to compare the basic material properties of concretes with th...

Perlite is a naturally occurring siliceous rock of volcanic origins. When heated to more than 1000-C it expands up to several times its original volume and thus creating the premises of light weightiness and thermal insulating properties. The indoor comfortable climate of modern lifestyle requires large amounts of energy to be created and sustained. This, in turn, leads to large amounts of CO2 being released in the atmosphere. Continuous research efforts are invested in creating materials with good insulation prop...