Brief overview on bio-based adhesives and sealants

Adhesives and sealants (AS) are materials with excellent properties, versatility, and simple curing mechanisms, being widely used in different areas ranging from the construction to the medical sectors. Due to the fast-growing demand for petroleum-based products and the consequent negative environmental impact, there is an increasing need to develop novel and more sustainable sources to obtain raw materials (monomers). This reality is particularly relevant for AS industries, which are generally dependent on non-sustainable fossil raw materials. In this respect, biopolymers, such as cellulose, starch, lignin, or proteins, emerge as important alternatives. Nevertheless, substantial improvements and developments are still required in order to simplify the synthetic routes, as well as to improve the biopolymer stability and performance of these new bio-based AS formulations. This environmentally friendly strategy will hopefully lead to the future partial or even total replacement of non-renewable petroleum-based feedstock. In this brief overview, the general features of typical AS are reviewed and critically discussed regarding their drawbacks and advantages. Moreover, the challenges faced by novel and more ecological alternatives, in particular lignocellulose-based solutions, are highlighted.Funding Agency Portuguese Foundation for Science and Technology PTDC/AGR-TEC/4814/2014; PTDC/ASP-SIL/30619/2017; IF/01005/2014.info:eu-repo/semantics/publishedVersio

Simulation of Industrialised Building System components production

The construction of IBS building should starts with the production of the IBS components and the production process is the main activity concerned in the IBS production plant. Having an optimum production line to manufacture the required IBS elements within targeted time and limited number of reusable steel mould is very important. In this study, workstation organization method has been adopted in the production of IBS component of beam and column. Witness 2001 simulation software has been used to model and simulate the most optimum production line set up. Here, two production lines set up have been proposed to complete the production of IBS beam and column between two and three months time with limited number of reusable steel mould to supply for the construction of medium size single storey IBS housing project ranging from 100 to 300 units. A contingency production line set up which able to complete the production of required IBS components within a month time with increased number of reusable steel mould has also been proposed. Number of resources such as workstation, tool, storage area and labour has been determined from the proposal. The proposed production line can be applied in the planning and cost estimating of IBS production plant set up

Escayola reforzada por acción sinérgica entre aditivos del hormigón (fluidificantes, superfluidificantes y aireantes-plastificantes) y fibras de vidrio E

Through the analysis of the different compounds (plaster + additives + E glass fibres) we pretend to demostrate that a synergic action is present between certain concrete additives (superfluidifiers, fluidiflers, and airingplasticizers) and E glass fibre, on the basis of the flection resistance of plaster matrix based compound materials.Mediante el análisis de diferentes compuestos (escayola + aditivos + fibras de vidrio E) se pretende demostrar que existe una acción sinérgica entre ciertos aditivos del hormigón (superfluidificantes, fluidificantes y aireantes-plastificantes) y los refuerzos a base de fibras de vidrio E, sobre la resistencia a flexión de los materiales compuestos de matriz principal escayola

An introductory study of Coal Fly Ash enhancement for heavy metal removal in wastewater treatment.

Coal Combustion Products are the materials that remain after pulverized coal is burned to generate electricity. The fine portion, fly ash, has many re-use capabilities across various industries. Most recent data shows that approximately 60% of fly ash produced in the United States was used with the largest re-use being concrete additives. This work aims to enhance fly ash via hydrothermal treatment in order to expand the re-use capabilities of the material. These materials were tested as adsorbents for heavy metal removal from wastewater samples. The metals tested for removal were Copper (II) Acetate, Cadmium Chloride, Boric Acid, Sodium Selenite, and Mercury (II) Chloride

Utilization of Palm Fiber and Sikacim Concrete Additive as Additional Materials in Concrete Mixtures Viewed From the Strength of Pulling

Concrete is an important material used in regional construction. The purpose of this study was to utilize palm fiber as an additive to increase the split tensile strength of concrete. In addition, the sicacim concrete additive is used as a chemical additive in concrete mixtures to produce higher-quality concrete. This study used sicacim concrete additives (0.08% cement) and palm fiber (4%, 5%, and 6% by weight) as cement substitutes. The components of the test object used in this study were vessels with a size of 15 x 30 cm, aged 28 years, and rut values of 60-180 cm—alloy configuration using SNI 03-2834-2000 technique. There are a total of 12 specimens, three for each variation. The finished test is a substantial elasticity test. Based on the research results, the split tensile strength of standard concrete is 3.52 MPa; the split tensile strength of concrete with a mixture of 4% palm fiber and 0.8% sicacim concrete additive is 3.69 MPa; the splitting tensile strength of concrete using a mixture of 5% palm fiber and 0.8% sicacim concrete additive is 4.09 MPa; then the tensile strength of the concrete uses a mixture of 6% palm fiber and 0.8%.ABSTRAKBeton merupakan bahan penting yang digunakan dalam pembangunan daerah. Tujuan penelitian ini adalah memanfaatkan ijuk sebagai bahan tambahan untuk imeningkatkan ikuat itarik ibelah ibeton. iSelain iitu, aditif betonisicacim digunakanisebagaiibahanikimia itambahan idalam campuran betonidalam upaya menghasilkan ibeton iyang ilebih iberkualitas. Dalam penelitian iini, iaditif ibeton isicacim i(0,08% isemen) idan iijuk (4%, 5%, dan 6% berat) digunakan sebagai pengganti semen. Komponen benda uji yang dimanfaatkan pada penelitian ini adalah bejana dengan ukuran yaitu 15 x 30 cm dengan umur 28 tahun, dan nilai rut 60-180 cm. Konfigurasi paduan menggunakan teknik SNI 03-2834-2000. Total ada 12 spesimen, tiga untuk setiap variasi. Uji selesai adalah uji elastisitas substansial. Berdasarkan hasil penelitian, daya tarik belah pada beton normal adalah diangka 3,52 MPa kuat tarik belah beton dengan campuran 4% ijuk dan 0,8% aditif beton sicacim adalah 3,69 MPa; daya tarik belah beton menggunakan bahan campuran 5% ijuk dan 0,8% aditif beton sicacim adalah 4,09 MPa; kemudian daya tarik belah beton menggunakan campuran sebesar 6% ijuk dan 0,8%

The Development of Penetration Charges for Increasing the Efficiency of the Interventions of Fire Rescue Service Units

During building fires is often necessary to deliver nozzles with water to the desired point of intervention and the wall or ceiling must be penetrated for energy supply and the entrance of persons. Access openings for extinguishing are created with hand tools or explosives, but it is a very time-consuming activity and fragmented material may endanger persons. Another possibility is the use of charges with a water layer, which absorbs the shock wave of the explosion at the back and at the same time significantly suppresses the fragmentation of the building element on which the charge acts. The penetration charge developed in two versions allows a sufficient penetration of the partitio

A NEW METHOD FOR THE CHARACTERISATION AND CLASSIFICATION OF THE INFRARED TRANSMISSION PROPERTIES OF MATERIALS WITH HIGH MOLECULAR WEIGHT OR COMPLICATED COMPOSITION USING THE PRIMA METHOD (PATTERN RECOGNITION BY INDEPENDENT MULTICATEGORY ANALYSIS)

In the present work multicomponent systems, in most cases natural samples were investigated with the purpose of identification, or determination of the chemical structure of the constituents. IR spectra of the samples were evaluated using the PRIMA (Pattern Recognition by Independent Multicategory Analysis) pattern recognition method. In the present report the application of the method to the identification of concrete additives, to the investigation of the degree of cross linking of dextran-based gel filters, and to studies on the chemical structure and composition of humic acids and tobacco plant parts is described. In some of the above cases the IR band positions are identical for all the samples, so new data, the relative absorbances calculated for some selected bands, have been introduced to quantitatively characterize the spectra. The method described is very simple and has proved to be very efficient in solving the problems outhived

Sustainable construction: construction and demolition waste reconsidered

Although the construction sector has suffered a great increase and development in later decades acting as the main economic leading force in many European countries, it has produced, nevertheless, a great problem regarding the increase in the generation of construction and demolition waste (C&DW). This, together with the fact that in many European countries the amount of recycled and reused C&DW is still quite low has engendered a serious environmental problem and an urge to develop strategies and management plans to solve it. As it is well known, demolition waste has quite a potential for reuse, although a correct and available development within the construction industry is, to a great extend, still missing due to the lack of sustainable and practical mechanisms provided. This article summarizes the different applications that are presently prospering in the elaboration of alternative uses for C&DW and proposes various measures and strategies to improve the processing of this waste. In order to be environmentally more effective, a conscious and thoughtful management plan needs to be implemented. More precisely, this study unfolds a holistic approach towards waste, in which ethical, and environmental as well as new applications in construction issues interact in order to improve the situation in an attempt to come closer to the future goal of achieving a sustainable growth

Photocatalytic Activity and Mechanical Properties of Cements Modified with TiO2/N

In this paper, studies of the mechanical properties and photocatalytic activity of new photoactive cement mortars are presented. The new building materials were obtained by the addition of 1, 3, and 5 wt % (based on the cement content) of nitrogen-modified titanium dioxide (TiO2/N) to the cement matrix. Photocatalytic active cement mortars were characterized by measuring the flexural and the compressive strength, the hydration heat, the zeta potential of the fresh state, and the initial and final setting time. Their photocatalytic activity was tested during NOx decomposition. The studies showed that TiO2/N gives the photoactivity of cement mortars during air purification with an additional positive effect on the mechanical properties of the hardened mortars. The addition of TiO2/N into the cement shortened the initial and final setting time, which was distinctly observed using 5 wt % of the photocatalyst in the cement matrix