Properties of concrete containing waste glass

In our study, in which waste glass (WG) is considered as coarse aggregates in the concrete, WG was used reduced to 4-16 mm in proportions of 0-60% in the production of PKÇ/B 32.5/R type cement. The effects of WG on workability and strength of the concrete with fresh and hardened concrete tests were analyzed. As a result of the study conducted, WG was determined not to have a significant effect upon the workability of the concrete and only slightly in the reduction of its strength. Waste glass cannot be used as aggregate without taking into account its ASR properties. As for cost analysis, it was determined to lower the cost of concrete productions. Our study was an environmental one in consideration to the fact that WG could be used in the concrete as coarse aggregates without the need for a high cost or rigorous energy.     

Tyre rubber waste recycling in self-compacting concrete

Rubberised self-compacting concrete was prepared containing different amounts of untreated tyre waste and their mechanical and microstructural behaviour are investigated and discussed in this paper. The fresh and hardened properties of such materials are compared with those of a typical reference formulation of self-compacting concrete. A comparison of the obtained compressive strengths with literature data confirms that self-compacting technology helps binding rubber phases.     

Flooding and floating in latex paint

Flooding and floating are problems in many paint applications. If pigment concentration is uniform on the surface but not through the thickness of the film, one refers to ‘flooding’ (horizontal separation). If, however, concentration differences are visible across the surface of the paint film, one refers to ‘floating’ (vertical separation). In this article, the influence of pigment, filler, additives, and processing conditions on the flooding and floating of colored latex paint were investigated. It was discovered that too broad a distribution of pigment and filler particle size can lead to flooding and floating. Different levels of pigment (TiO₂) or filler (kaolin) loading cause diverse degrees of flooding and floating. Waterborne coatings that do not exhibit flooding or floating may show these conditions when diluted. Using dispersants or thickeners with hydrophobic constituents, increasing viscosity, reducing surface tension, etc., all help to prevent or reduce flooding and floating. Comparison tests revealed little influence of processing conditions on flooding or floating.     

Development of waste tire modified concrete

In this study, waste tire modified concrete was investigated experimentally. Two types of waste tire configurations were evaluated. One was in the form of chips, or particles, and the other was in the form of fibers. For the waste tire chip modified concrete, surface treatment by saturated NaOH solution and physical anchorage by drilling a hole at the center of the chips were also investigated. For the waste tire fiber modified concrete, fibers with various aspect ratios were utilized. A hybrid fiber reinforcement using waste tire fiber and polypropylene (PP) fiber was also investigated. The effect of waste tire resources (car tires or truck tires) on the strength and stiffness was evaluated. A total of 10 batches of concrete, which yielded sixty φ152.4×304.8 mm cylinders, were prepared. Compressive strength, compressive modulus of elasticity, Poisson's ratio, and split tensile strength tests were conducted on the prepared samples. Ways to further recover the lost strength and stiffness of waste tire modified concrete were discussed based on the test results.     

废弃PVC电缆料的回收利用及性能研究

将聚氯乙烯(PVC)电缆料废弃物(wPVC)通过双螺杆挤出机,把不同份数的wPVC加入到未使用过的J-70型PVC电缆料(J-70PVC)中混合制备wPVC/J-70PVC,再用注射机注塑成型的方法来制得标准样条.研究不同配比wPVC/J-70PVC的拉伸、热老化、体积电阻率等性能,并对其拉伸断面形貌的微观性能进行测试...     

日本废旧复合材料再生利用现状

本文介绍了日本在处理废旧复合材料并将其再生利用方面的研究工作和进展。阐述了目前对旧的热固性复合材料制品以及在制造复合材料制品过程中产生的边角废料的处理方法，同时说明了这项事业的现状及趋势。     

DSC evaluation of binder content in latex paints

The estimate by differential scanning calorimetry of the enthalpy of thermal decomposition of the organic fraction in a complex material can be used, in proper conditions, for evaluating the concentration of the organic components. The application of this technique of thermal analysis to latex paints aimed at identification of binder content is discussed in this paper. On the one hand it gives good results on binder content estimate; on the other hand it highlights some aspects of the thermal decomposition of polymers enclosed in an inorganic matrix. The phenomena of thermal decomposition are studied for the main components of latex paints, i.e. for polymers, and for complete paint formulations. The materials considered include widely used binders for the manufacture of latex paints such as vinyl acetate/Versatate copolymers and styrene/acrylic copolymers, rheology modifiers such as cellulose ethers and other standard components of latex paints. Formulations representing typical latex paints with different binder content and simplified polymer/filler systems are considered. Although decomposition paths are very different for different polymers and for the same polymer in different concentrations, the overall heat output is consistent and proportional to the amount of polymer in the sample. Therefore identification by DSC measurements of the binder content in a latex paint appears as a feasible technique.     

Modification of the properties of concrete by a new pozzolan—a waste catalyst from the catalytic process in a fluidized bed

The zeolitic waste material studied (fluidized bed cracking catalyst, FBCC) is characterised by a content of more than 90 wt.% of SiO₂ and Al₂O₃, a mean grain size within 20-80 μm, and a specific surface above 100 m²/g. Its chemical composition makes it similar to some fly ashes and metakaolin. The present work was devoted to the study of the mechanism of interaction of FBCC with Portland cement and of the pozzolanic activity. Concretes were made with FBCC additions of 10% and 20% (relative to the mass of cement) used as a substitute for the sand aggregate fraction, and the following properties of the concretes were determined under nonaggressive conditions: compressive strength, porosity, water absorption, frost resistance, and steel passivation ability. It has been found that FBCC has pozzolanic properties, and its pozzolanic activity depends on its grain size. FBCC favourably modifies the porous structure of the concretes, increases their compressive strength, density, and frost resistance, and reduces water absorption. The effectiveness of FBCC increases under conditions of strong dispersion. FBCC does not deteriorate the steel passivation ability of concrete when used as a 10% additive, but at a content of 20 wt.%, it can make difficult the formation of a passive layer that conforms to the Polish standards.     

Use of municipal solid waste incineration fly ash in concrete

With a view of reducing the quantities to be landfilled, the Solvay Company has been working on the development of a new physicochemical treatment for municipal solid waste incineration (MSWI) fly ashes: the Revasol process. This process allows reducing the soluble fraction, fixing heavy metals and eliminating dioxins. This article reports on the characteristics of a treated ash and on its use in concrete. For the latter point, three characteristics were chosen: the compressive strength and the durability of the hardened concrete and its behavior to leaching. From mechanical and durable points of view, the ash incorporated in the concrete behaves like ordinary sand. The leaching tests carried out on the concrete confirm that the process makes it possible to obtain materials without major risks for the environment. Also, these results as a whole suggest that the use of waste in concrete constitutes a potential means of adding value.     

乳胶漆生产废水处理的研究

随建筑业的发展,建筑乳胶漆的应用日益广泛。乳胶漆生产过程中工业废水的处理也逐渐显得重要。本论文研究了一系列絮凝剂,即无机和有机、小分子和高分子的复合,对乳胶漆废水进行处理。另外,研究了对不同pH工业废水絮凝沉淀的影响。研究结果在工厂的废水处理中取得较理想的效果。     

Recycling of waste lubricant oil into chemical feedstock or fuel oil over supported iron oxide catalysts

The recycling of waste lubricant oil from automobile industry was found to be best alternative to incineration. Silica (SiO₂), alumina (Al₂O₃), silica-alumina (SiO₂-Al₂O₃) supported iron oxide (10 wt% Fe) catalysts were prepared by wet impregnation method and used for the desulphurisation of waste lubricant oil into fuel oil. The extent of sulphur removal increases in the sequence of Fe/SiO₂-Al₂O₃<Fe/Al₂O₃<Fe/SiO₂ and this might be due to the presence of smaller crystalline size (7.4 nm) of Fe₂O₃ in Fe/SiO₂ catalyst. X-ray diffraction results suggest the presence of iron sulphide in the used catalyst. Gas chromatography with thermal conductivity detector analysis confirms the presence of H₂S in gaseous products. In addition, Fe/SiO₂ catalyst facilitated the formation of lower hydrocarbons by cracking higher hydrocarbons (≈C₄₀) present in waste lubricant oil.     

Studies on mechanical properties of concrete containing waste glass aggregate

Quantities of waste glass have been on the rise in recent years due to an increase in industrialization and the rapid improvement in the standard of living. Unfortunately, the majority of waste glass is not being recycled but rather abandoned, and is therefore the cause of certain serious problems such as the waste of natural resources and environmental pollution. For these reasons, this study has been conducted through basic experimental research in order to analyze the possibilities of recycling waste glasses (crushed waste glasses from Korea such as amber, emerald green, flint, and mixed glass) as fine aggregates for concrete. Test results of fresh concrete show that both slump and compacting factors are decreased due to angular grain shape and that air content is increased due to the involvement of numerous small-sized particles that are found in waste glasses. In addition the compressive, tensile and flexural strengths of concrete have been shown to decrease when the content of waste glass is increased. In conclusion, the results of this study indicate that emerald green waste glass when used below 30% in mixing concrete is practical along with usage of 10% SBR latex. In addition, the content of waste glasses below 30% is practical along with usage of a pertinent admixture that is necessary to obtain workability and air content.     

废润滑油的再生工艺研究

针对现有的废润滑油回收利用技术都没有彻底地脱除废润滑油中金属等杂质、没有提出理想的环境友好的回收再生技术、没有很好地提高润滑油基础油的收率等问题,结合废润滑油的性质特点,探索了一种环境友好的回收再生技术,提出了不同常规的再生工艺,基础油收率高,效果显著,再生后符合润滑油基础油标准,可以用作基础油。     

The microstructure of concrete made with municipal waste incinerator bottom ash as an aggregate component

The interaction of municipal solid waste incinerator bottom ash (MSWI bottom ash), when utilized as an aggregate in concrete, with the cement matrix was investigated. The most prominent reaction observed in lab and field concrete was the formation of aluminium hydroxide and the release of hydrogen gas from aluminium grains reacting in the alkaline environment. The expansive aluminium reaction was identified as a main cause of extensive spalling on the concrete surface. Due to the higher content of bottle glass as part of the ash, in all samples, reaction products of an alkali-silica reaction (ASR) could be observed as well. However, damage due to ASR were less severe than those caused by the aluminium reaction. The expansion rates were low and only a few of the lab samples showed cracking. Microstructural analysis of the samples indicated clearly that a large quantity of the alkali-silica gel which was formed was accommodated in the pores and voids without exerting any strain on the material.     

Viscoelastic properties of latex paint films in tension: Influence of the inorganic phase and surfactants

The tensile properties of latex coatings were investigated with a set of custom formulated artist-type paints at an age of 1 year. All films in the study contained a poly(methyl methacrylate-cobutyl acrylate) binder exhibiting a glass-transition at approximately 10 °C. The viscoelastic behaviour of the latex matrix is first highlighted through a series of experiments involving different strain histories and temperatures. Influence of the inorganic particle concentration and geometry is then illustrated using TiO₂ and calcined kaolin for the secondary phase. Experimental data from a wide range of conditions are summarised through master curves of secant modulus and failure strains using time–temperature superposition. The results indicate that the latex films behave in a rheologically simple manner and it is possible to predict the response outside of the experimental time-scale. An analysis by similar methods is also given for TiO₂ pigmented films with/without surfactant removed by immersion in water. Differential scanning calorimetry and atomic force microscopy were also used in conjunction with mechanical tests. The combined findings suggest that a fraction of surfactant migrates to the TiO₂ interface during film formation, where it interferes with adhesion of the acrylic matrix.     

Experimental limitations regarding the formation and characterization of uranium-mineral phases in concrete waste forms

Predicting the fate of low-level radioactive waste (LLW) requires understanding radionuclide-waste form interactions. Concrete encasement is one method being considered for containment of LLW. The formation of uranium-mineral phases has been investigated in simulated concrete pore fluids and waste forms. X-Ray diffraction analyses of uranium precipitates from concrete pore fluids suggest uranium salts and -silicates are solubility-limiting phases. Scanning electron microscopy-energy dispersive spectroscopic analyses of uranium-spiked concrete suggest that under conditions both under-saturated and over-saturated with respect to the formation of uranium phases, uranyl-oxyhydroxide phases precipitate within the initial two weeks. Uranyl-silicate phases form after approximately one month and uranyl-phosphate phases provide a significant contribution to uranium retention in concrete waste forms after two months. This investigation demonstrates the importance of 1) studying the interaction of uranium in the complete matrix (i.e., concrete matrix versus pore fluids) and 2) formation of uranium-mineral phases on the retention of uranium within concrete waste forms.     

Experimental investigation of the effect of temperature on the first desorption isotherm of concrete

In the framework of the radioactive waste management in France, interim storage concrete structures should be submitted to temperatures up to 80 °C and subsequent desiccation. The impact of temperature on the sorption properties of concretes has been poorly studied and results are scarce. An experimental campaign was thus carried out to characterize the first desorption isotherms of a modern concrete at 30 °C and 80 °C. The results show a significant influence of the temperature increase that will have to be accounted for the durability assessment of the long-term interim storage concrete structures. Investigating the causes of these modifications, it appeared that desorption induced by temperature might be the principal mechanism rather than microstructure alteration and water properties evolution.     

Modeling of chloride ion ingress in coastal concrete

The behavior of chloride ions introduced into concrete from concrete surface by marine environment and by use of marine aggregate was analyzed for a coastal concrete structure. A mathematical model including the diffusion of chloride ion in aqueous phase of pores, the adsorption and desorption of chloride ions to and from the surface of solid phase of concrete, and the chemical reactions of chloride ions with solid phase was presented. Finite element method was employed to carry out numerical analysis. Quantitative analysis was conducted to measure the distribution of the free chloride ion concentration in aqueous phase of concrete with potentiometric titration based on ASTM D 1820. The concentration profiles of chloride ions predicted by the mathematical model agreed favorably with the measured data. The results of this study may be used to predict the onset of reinforcement corrosion and to identify the maximum limit of chloride ions contained in concrete admixtures.     

Surfactants in latex films; interactions with latex components and quantitative analysis using ATR and step-scan PAS FT-IR spectroscopy

This paper focuses on the behavior of low-molecular-weight surfactant molecules in latex films and how their distribution may influence coalescence and other film properties. Using recently developed spectroscopic non-destructive analytical tools, quantitative assessments concerning surfactant distribution and their interactions with latex components will be presented. Particular efforts will be given to recent developments in quantitative analysis using attenuated total reflectance (ATR) and step-scan photoacoustic (S²-PAS) Fourier transform infrared (FT-IR) spectroscopy.