Application Of Building Materials Research Articles

Photocatalytic cement-based materials: Comparison of nitrogen oxides and toluene removal potentials and evaluation of self-cleaning performance

Using cement-based building materials as a matrix for nano-photocatalysts is an important development for the large scale application of photocatalytic technologies. Air pollution mitigation and self-cleaning surface are two major applications of photocatalytic building materials. In this study, a comparison was made to evaluate the performance of TiO 2 modified concrete surface layers for NO x and VOC degradation. The self-cleaning performance of TiO 2 modified self-compacting mortars (SCM) developed for decorative applications was also evaluated. The results show that the photocatalytic conversion of toluene by the TiO 2 modified surface layer was not detected, although NO x could be effectively removed under the same conditions. The presence of toluene did not influence the NO x removal process. TiO 2 modified SCM were found to be effective in the discoloration of rhodamine B under UV and strong halogen light irradiation. The level of adsorption of the air contaminants onto the active sites of the cement-TiO 2 composite was identified to be the key factor determining the subsequent photocatalytic efficiency.

THE CONSTRUCTIVE DECISION AND BUILDING MATERIALS OF EXHIBITION PAVILIONSOF GREAT BRITAIN THROUGH THE EXAMPLE THE FIRST AND LAST WORLD EXHIBITION-EXPO

The results of investigating structural solution and building materials of exhibition pavilions of Great Britain taken at different epochs are presented in this article. Features of architectural formation of exhibition pavilion demonstrate the application of new building materials and constructions. There is presented the development building technology trends, which find the further application in the world architecture. Innovative architectural methods, the unusual thing of setting and forms of pavilions show the achievements of Great Britain in such areas as science, culture, technology and building materials at its best.

N2‐filled hollow glass beads as novel gas carriers for microcellular polyethylene

AbstractN2‐filled hollow glass beads (HGB) were first used as novel gas carriers to prepare microcellular polymers by compression molding. Dicumyl peroxide was acted as crosslink agent to control the produced microcellular structure of low density polyethylene (LDPE)/HGB. The effect of temperature, pressure and the content of gel on the embryo‐foaming, and final‐foaming structure are investigated. Scanning electronic microscopy shows that the average cell size of microcellular LDPE ranges from 0.1 to 10 μm, and the foam density is about 109–1011 cells/cm3. A clear correlation is established between preserving desirable micromorphologies of microcellular LDPE in different processing stage and tuning processing factors. The pertinent foaming mechanism of microcellular materials foamed with HGB is proposed. Because of the good mechanical strength, low density, weak water‐absorption, and excellent heat insulate ability, microcellular LDPE has great potential application in energy building materials. © 2009 Wiley Periodicals, Inc. J Appl Polym Sci, 2009

Photocatalytic construction and building materials: From fundamentals to applications

Heterogeneous photocatalysis has been intensively studied in recent decades because it only requires photonic energy to activate the chemical conversion contrasting with conventional catalysis which needs heat for thermo-activation. Over the years, the theories for photochemical activity of photocatalyst including photo-induced redox reaction and super-hydrophilic conversion of TiO 2 itself have been established. The progress in academic research significantly promotes its practical applications, including the field of photocatalytic construction and building materials. TiO 2 modified building materials are most popular because TiO 2 has been traditionally used as a white pigment. The major applications of TiO 2 based photocatalytic building materials include environmental pollution remediation, self-cleaning and self-disinfecting. The advantage of using solar light and rainwater as driving force has opened a new domain for environmentally friendly building materials. In this paper, the basic reaction mechanisms on photocatalyst surface under the irradiation of ultraviolet and their corresponding applications in building and construction materials are reviewed. The problems faced in practical applications and the trends for future development are also discussed.

Developing unfired stabilised building materials in the UK

This paper discusses laboratory tests on Lower Oxford Clay (LOC) stabilised using different levels of lime (L) or Portland cement (PC), with and without blending with ground granulated blast-furnace slag (GGBS). LOC is used by Hanson Brick Company Ltd in the manufacture of fired ‘London’ bricks at the Stewartby brick plant in Bedfordshire. The research investigated L-PC, L-GGBS and PC-GGBS blends to assess their potential for application in sustainable unfired clay building materials (bricks, mortar, etc.). Use of unfired materials reduces not only energy costs, but also environmental damage associated with the traditional firing process used in the manufacture of clay building components. Due to the high strength requirements of the building industry compared with, for example, stabilised highway pavement layers, a high maximum stabiliser dosage of 20% was used. For road construction, typical stabiliser dosages are 3–8% for lime and 3–5% for PC. In the current investigation, cylindrical test specimens were cured for 28 days at moisture contents of 25, 30, 35 and 40% before testing for unconfined compressive strength. Preliminary results show that the strength values for all stabilised material investigated was within the strength range of 737–2077 kN/m2 at 28 days, with L-PC blends tending to achieve lower strength values than L-GGBS blends. Overall results suggest that there is potential in using GGBS-based binders for the manufacture of unfired building components.

Manufacture of Syntactic Foams Using Starch as Binder: Post-Mold Processing

Syntactic foam manufacturing method, ‘post-mold processing,’ based on the buoyancy of hollow microspheres was studied for potential building material applications. The post-mold processing involves mixing starch particles and ceramic hollow microspheres in water. It was found starch particles tend to adhere to hollow microspheres, forming agglomerations, during mixing. It was also found that “volume fraction of starch particles on a microsphere making a relative density of 1.0” (VFSMRD) is an indicator for mixture volume transitions. Both the maximum total volume expansion of mixture and a transition in formation, after phase separation, of mixture volume in water referred to as “top phase” in a mixing container were taken place at a calculated VFSMRD. It was found that hollow microsphere size effect on attracting starch particles was relatively high but IBVMS effect was not significant. Also, no effect of water volume for a given diameter of cylindrical container was found. Starch-microsphere inter-distance was discussed and considered to be an important parameter affecting starch content in an agglomeration. A Simple Cubic cell model for the starch-microsphere inter-distance was adopted to quantitatively explain various effects on starch content in agglomeration such as hollow microsphere size, initial bulk volume of hollow microspheres (IBVMS), and water volume. Further, the following were found for manufactured syntactic foams: (a) volume fraction of starch in foam is of linear relation with starch content before mixing for a given experimental data range and (b) shrinkage is relatively high for small hollow microspheres with high starch content.

Thermal Characteristics of New Building Materials and their Effect upon the Energy Efficiency

Thermal Characteristics of New Building Materials and their Effect upon the Energy Efficiency The paper formulates the role of thermal inertia of the building materials in the energy supply of buildings and in solution of the energy efficiency problems. The evolution of construction entails the application of new building materials as well as of glazed surfaces in the envelopes of buildings. An analysis is made of the influence of the thermal resistance of building materials and their heat capacity on the thermal inertia indicators of buildings. An inertia scale of buildings has been developed for the choice of the heat supply capacities of buildings at low outdoor temperatures under extreme conditions of the Latvian climate. The ratio of the ventilation capacities has been analysed in the total heating balance at a low thermal inertia of buildings. The significance of innovative ventilation technologies for raising the energy efficiency has been considered.

Environmental and economic life cycle assessment for sewage sludge treatment processes in Japan

Life cycle assessment for sewage sludge treatment was carried out by estimating the environmental and economic impacts of the six alternative scenarios most often used in Japan: dewatering, composting, drying, incineration, incinerated ash melting and dewatered sludge melting, each with or without digestion. Three end-of-life treatments were also studied: landfilling, agricultural application and building material application. The results demonstrate that sewage sludge digestion can reduce the environmental load and cost through reduced dry matter volume. The global warming potential (GWP) generated from incineration and melting processes can be significantly reduced through the reuse of waste heat for electricity and/or heat generation. Equipment production in scenarios except dewatering has an important effect on GWP, whereas the contribution of construction is negligible. In addition, the results show that the dewatering scenario has the highest impact on land use and cost, the drying scenario has the highest impact on GWP and acidification, and the incinerated ash melting scenario has the highest impact on human toxicity due to re-emissions of heavy metals from incinerated ash in the melting unit process. On the contrary, the dewatering, composting and incineration scenarios generate the lowest impact on human toxicity, land use and acidification, respectively, and the incinerated ash melting scenario has the lowest impact on GWP and cost. Heavy metals released from atmospheric effluents generated the highest human toxicity impact, with the effect of dioxin emissions being significantly lower. This study proved that the dewatered sludge melting scenario is an environmentally optimal and economically affordable method.

Study on preparation of montmorillonite-based composite phase change materials and their applications in thermal storage building materials

Three composite phase change materials (PCMs) were prepared by blending butyl stearate, dodecanol and RT20 with an organically modified montmorillonite (MMT), respectively. After the three composite PCMs were characterized by DSC, it was indicated that the RT20/MMT composite PCM was a good candidate for building applications due to its large latent heat, suitable phase change temperature and good performance stability. Compared with RT20, the RT20/MMT composite PCM exhibited higher heat transfer efficiency and had good compatibility with gypsum due to the combination with MMT. The composite gypsum boards containing RT20/MMT composite PCM had the function of reducing building energy consumption by reducing the indoor temperature variation, and the function was enhanced with the increase in the mass ratio of the RT20/MMT composite PCM.

Novel syntactic foams made of ceramic hollow micro-spheres and starch: theory, structure and properties

Novel syntactic foams for potential building material applications were developed using starch as binder and ceramic hollow micro-spheres available as waste from coal-fire power stations. Foams of four different micro-sphere size groups were manufactured with either pre- or post-mould gelatinization process. They were of ternary system including voids with a foam density range of approximately 0.33–0.44 g/cc. Compressive failure behaviour and mechanical properties of the manufactured foams were evaluated. Not much difference in failure behaviour or in mechanical properties between the two different processes (pre- and post-mould gels) was found for a given binder content. Compressive failure of all syntactic foams was of shear on plane inclined 45° to compressive loading direction. Failure surfaces of most syntactic foams were characterized by debonded micro-spheres. Compressive strength and modulus of syntactic foams were found to be dependant mainly on binder content but mostly independent of micro-sphere size. Some conditions of relativity arising from properties of constituents leading to the rule of mixtures relationships for compressive strength and to understanding of compressive/transitional failure behaviour were developed. The developed relationships based on the rule of mixtures were partially verified. Some formation of starch webs on failure surfaces was discussed.

A novel montmorillonite-based composite phase change material and its applications in thermal storage building materials

A novel composite phase change material (PCM) was prepared by blending an organic PCM with an organic-modified montmorillonite. The thermal characteristics of the composite PCM were close to those of the pure PCM, and 1500 times heating–cooling cycles test showed that the composite PCM had good performance stability. Compared with the pure PCM, the composite PCM exhibited higher heat transfer rate owing to the combination with montmorillonite. The composite PCM had a good compatibility with gypsum powders, and the composite gypsum boards prepared had a function of cutting down energy consumption by decreasing the frequency of internal air temperature swings.

Cumulative metal leaching from utilisation of secondary building materials in river engineering

The present paper estimates the utilisation of bulky wastes (minestone, steel slag, phosphorus slag and demolition waste) in hydraulic engineering structures in Dutch parts of the rivers Rhine, Meuse and Scheldt over the period 1980-2025. Although they offer several economic, technical and environmental benefits, these secondary building materials contain various metals that may leach into river water. A leaching model was used to predict annual emissions of arsenic, cadmium, copper, chromium, lead, mercury, nickel and zinc. Under the current utilisation and model assumptions, the contribution of secondary building materials to metal pollution in Dutch surface waters is expected to be relatively low compared to other sources (less than 0.1% and 0.2% in the years 2000 and 2025, respectively). However, continued and widespread large-scale applications of secondary building materials will increase pollutant leaching and may require further cuts to be made in emissions from other sources to meet emission reduction targets and water quality standards. It is recommended to validate available leaching models under various field conditions. Complete registration of secondary building materials will be required to improve input data for leaching models.

55%Al-Zn合金めっき鋼板の皮膜特性に及ぼす化成処理皮膜成分の影響

The influence of the organic composite coating components on various properties of 55%Al-Zn alloy coated steel sheet have been investigated by salt spray test, draw bead test and the measurement of Cr fixation ratio. In addition, the relationship between these properties and the film structure was studied by SAM analysis.The coating, which was composed of newly developed Acrylic resin, phosphate and Cr compound was found to provide good corrosion resistance, formability, good appearance and film insolubility. Further, the results from the film structure analysis show that this coating was characterized by its gradient composition. The layer material in contact with the 55%Al-Zn alloy coated steel sheet is an insoluble passivation layer, rich in chromic compounds and phosphate, which provides superior corrosion resistance and film insolubility. The layer material on the outer surface consists primarily of organic resin and is sufficiently flexible to ensure good formability.This new organic composite coating on 55%Al-Zn alloy coated steel sheet is commercially produced for building materials applications.

Application of earth building materials for low-income housing in the tropics

The characteristics, properties, problems and other factors associated with earth materials for building houses, especially in the tropical regions of the world are identified. The inter-relationships among these factors which inhibit the adoption of earth materials and the recommendations for overcoming the problems in a coordinated manner are discussed. The information and solutions provided would enable economic and appropriate measur-es to be taken to make earth buildings safer and more durable. (Journal of Applied Science and Technology: 2001 6(1-2): 40-45)

Mechanization and Costs of Primary Production Chains forMiscanthus x giganteusin The Netherlands

Miscanthus, a new perennial crop for biomass production can be used as raw material for energy, building materials, geotextiles and paper pulp. Plant propagation can be performed by means of tissue-culture-propagated plants or by rhizomes. In the latter case, the farmer can produce them on his farm from 2–3yr old plants, which will reduce costs compared to micropropagation. Methods were developed for harvesting and planting of rhizomes. Harvest of the crop is influenced by the destination of the raw material and the drying and storage methods. Harvesting can be done by existing mowing, baling and chopping machines for some building material applications and energy and paper pulp use. For utilization of Miscanthus as special building materials and geotextiles whole stems are required, and machines for mowing and bundling of whole stems are a necessity. Different storage possibilities have been investigated. Selection of the most appropriate method can be performed only by comparing complete production chains from field harvest to delivery at the processing plant. Costs of different chains are compared from soil preparation to transport to the processing plant. Self-propelled baling is one of the lowest cost options but chopping and compaction after storage is also an attractive option, since drying is possible and transport costs are lower.

Springer Series in Electrophysics Vol 17: Concert Hall Acoustics

Y Ando 1985 Berlin: Springer xii + 151 pp price DM118 ISBN 3 540 13505 7 Over the ages, with a few notable exceptions, such as Wagner at Bayreuth, music appears to have evolved slowly so as to suit available space, rather than vice versa. Application of modern building techniques and materials is likely to change the character of such music and lead to criticism from the audience unless the necessary steps are taken to reproduce a 'correct' acoustic environment associated with the music.