Raw Material For Construction Research Articles

Environmental and technical assessments of the potential utilization of sewage sludge ashes (SSAs) as secondary raw materials in construction

Ashes produced by thermal treatments of sewage sludge exhibit common properties with cement. For example, major elements present in SSA are the same of major elements of cement. Hydraulic properties of SSA are quite the same of cement ones. They may therefore be used to substitute part of cement in concrete or other cementitious materials, provided that technical prescriptions are satisfied and that environmental risks are not significantly increased.The objective of the present study was to determine the appropriate substitution ratios to satisfy both technical and environmental criteria. In a first step, the elemental composition and particle size distribution of the ashes were measured. Then the ashes were used along with Portland cement and sand at different ratios of substitution to produce mortar and concrete which were cured for up to 90days into parallelepipedic or cylindrical monoliths. The mechanical properties of the monoliths were measured using standard procedures for flexural and compressive strengths, and compared to blanks containing no ashes. The environmental criteria were assessed using leaching tests conducted according to standard protocols both on the ashes and the monoliths, and compared to the blanks.Results showed that the characteristics of the ashes ranged between those of cement and sand because of their larger particle size and higher content in SiO2 as compared to cement. The monoliths made with the highest substitution ratios exhibited a significant decrease in flexural and compressive strengths. However, when the ashes were used in partial substitution of cement at appropriate ratios, the concrete monoliths exhibited similar compressive strengths as the blank samples. The most appropriate ratios were found to be 10% substitution of cement and 2% substitution of sand.The leaching tests conducted on the ashes in their powdery form revealed that amongst the potential contaminants analyzed only Mo and Se were leached at concentrations above the threshold limits considered. The leaching tests conducted on concrete monoliths showed however that none of the contaminants monitored, including Mo and Se, were leached above the limits. In addition, whether concrete recipe incorporated ashes or not, similar concentrations were measured for each potential contaminant in the leachates. This result indicated that mixing ash with cement and sand to produce mortar or concrete induced a stabilization of Mo and Se and thereby constituted in itself a good treatment of the ashes.

Elemental analysis of marble used in Saudi Arabia by different nuclear analytical techniques

Instrumental neutron activation analysis (INAA) and HPGe detector γ-spectroscopy were used to determine a total of 22 elements qualitatively and quantitatively for the first time from marble rock samples collected from local markets in Saudi Arabia. The elements determined are Mg, Ca, V, Na, Mn, As, La, Sm, U, Sc, Cr, Fe, Co, Zn, Sn, Ba, Ce, Eu, Yb, Lu, Hf, and Th. The samples were properly prepared together with their standard reference material and simultaneously irradiated by thermal neutrons at the TRIGA Mainz research reactor at a neutron flux of 7×1011n/cm2s. XRF was also used. The concentrations of natural radionuclides 226Ra, 232Th and 40K were also determined by gamma ray spectroscopy to estimate the radiological parameters such as radium equivalent activity, and the external hazard index was calculated to estimate the exposure risk from usage of marble as raw materials in construction. For the sake of comparison the results of concentration levels and radium equivalent activities are compared with similar studies carried out in other countries.

Natural radioactivity of bricks and brick material in the Salihli-Turgutlu area of Turkey

Some of the rocks and soil-originated materials used in building construction are the serious natural radiation sources. Soil-originated bricks and roof-tiles and their raw material in the Salihli-Turgutlu area were tested in situ for natural radiation levels using a gamma-ray spectrometer. The concentrations of the radioelements 40K, 238U and 232Th and air-absorbed radiation rates were measured for soil, raw material heaps, brick and roof-tile stacks and waste brick heaps. The radium-equivalent activity Raeq of the raw material varied between 187.9 and 216.4 Bq kg−1. The external radiation hazard index Hex values ranged between 0.51 and 0.58. For building material and its products, recommended Raeq and Hex levels are 370 Bq kg-1 and 1.0, respectively. On the other hand, both Raeq and Hex values for waste brick heaps, containing broken brick pieces, coal pieces and ash, were higher than the recommended levels, i.e. Raeq values varied from 473.8 to 651.0 Bq kg-1 and Hex values were within the range 1.15–1.76. The annual dose rate and radium-equivalent activity values of the brick and roof-tiles were below the level of criteria. Annual dose rate ranged between 0.42 and 0.62 mSv y−1 and radium equivalent activity was in the range 172.9–245.2 Bq kg−1. The external and internal radiation hazard indices were all below the value of 1.0 for the Salihli-Turgutlu area bricks and roof-tiles. Results of this study were compared with results of previous studies. Natural radiation levels of construction raw material of study area are generally higher than of those of previous studies.

Behaviour of Different Types of Sand Randomly Mixing with Various Natural Fibers

For rapid expansion in transportation sector in India, a huge amount of construction of roads are being made through different schemes. Such constructions require massive quantity of conventional good brickbats for sub-base construction. But due to scarcity of raw materials for construction of good bricks and dearness of energy to make bricks, use of alternate materials for making sub-base is becoming more obligatory. In such condition, use of natural sands is being advocated. To improve the properties of such sands, to suit subbase characteristics, some natural fibers like jute, coir or Sabai grass can be used in random mixing with these sands, with the aim to increase the strength and decrease in deformability of the laid subbase layer. This work highlights the usefulness of construction of sub-base with sand and natural fibers composite system, as alternate material of construction.

Chapter 9 Materials for construction in deserts

Civil engineering constructions of all kinds use large quantities of natural materials ranging from soils and clays through sand, gravel and crushed rock to large blocks of rock, which may be used as armourstone, for shaping into dimension stone, or as cladding, tiles or pavers. Excavation, cuttings and ground preparation associated with many construction projects require large volumes of soil and rock to be removed. Where possible, this bulk material is reused as foundation layers for buildings and roads, and, more commonly, as fill for embankments or bunds. Today, there is increasing pressure to reuse or recycle the demolition waste materials from redundant buildings. Timber is a scarce commodity in desert regions and is usually imported. Consequently, it is often reused or used as a fuel source. However, it is also becoming more common for solid building wastes such as concrete and brick to be recycled as ‘secondary’ aggregate or fills. Natural geological materials of all kinds may be found in desert regions and are described in Chapters 3 and 5. They are similar to materials found in other parts of the world, but the special environmental conditions of deserts (as described in Chapters 2–4) can lead to the alteration of these geological materials to form unique associations of rock, and also to create new ones that are specific to deserts. Where possible, the bulk natural raw materials for construction in deserts are sourced locally, which may imply that less than ideal material will have to be used in some circumstances. The uses of natural materials in construction can be categorized under the following general applications:

Properties of EPS RHA lightweight concrete bricks under different curing conditions

The depletion of non-renewable resources has become an alarming issue nowadays. Many environmentalists and researchers have been investigating the use of waste materials as a renewable resource for use especially as raw materials in construction. This paper reports on the potential use of waste rice husk ash (RHA) and expanded polystyrene (EPS) beads in producing lightweight concrete bricks. The RHA was used as a cementitious material since it is a lightweight reactive pozzolanic material. RHA was used as partial cement replacement, while the EPS was used as partial aggregate replacement in the mixes. Bricks of 215 mm × 102.5 mm × 65 mm in size were prepared in this study. The engineering properties of the bricks were investigated. Among the properties studied were hardened concrete density, compressive strength and water absorption of the EPS RHA concrete bricks. Scanning electron microscopy (SEM) analysis was also performed on the brick samples. Four types of curing conditions were employed in this study. These include full water curing, air dry curing, 3-day curing and 7-day curing. It was found that the properties of the bricks are mainly influenced by the content of EPS and RHA in the mix and also the curing condition used.

Recycling of the product of thermal inertization of cement–asbestos for the production of concrete

A novel field of research in materials science is the recycling of secondary raw materials for construction and building materials such as concrete. This paper describes the successful recycling of as much as 20 wt% of the product of thermal transformation of cement–asbestos for the formulation of concrete. The main mineralogical phases present in the product of transformation of cement–asbestos are C2S, ferrite, and Al-, Ca-, Mg-rich silicates such as akermanite (ideally Ca 2MgSi 2O 7) and merwinite (ideally Ca 3Mg 2Si 2O 8). The behavior of this secondary raw material, termed KRY·AS, in commercial concrete was investigated using five different mixtures in which various portions (0, 5, 10, 15 and 20 wt%) of cement were substituted by KRY·AS. The results of preliminary technological tests (slump test, compressive strength, flexural strength after 28 days, and depth of penetration of water under pressure after 28 days) were discussed and interpreted with the aid of chemical, mineralogical and SEM analyses. One of the major results is that after 28 days, although all the concrete samples are invariably classified as “ordinary concrete” according to the UNI 6132 tests, those diluted with KRY·AS display a lower resistance to compression with respect to the standard. On the other hand, they recover compressive strength and display values identical to that of the standard after 90 days. The addition of the secondary raw material has the effect to slow down the kinetics of setting/hardening because the main cement phase present in KRY·AS is C2S which has a slower rate of hydration with respect to C3S.

Factores que influyen en la decisión de licitar o no licitar en la Franja de Gaza - perspectivas de los contratistas

To bid or not to bid for a certain project is considered to be a crucial decision for contractors' survival. The objective of this paper is to identify and rank the factors that affect the bid/no bid decision according to their relative importance from the perspective of the local contractors operating in the Gaza Strip, Palestine. A total of seventy-eight factors were identified through a comprehensive literature review to evaluate the most important factors that affect the contractors' decisions to bid or not in the Gaza strip. A survey was conducted on a sample of seventy three contractors classified under the building category, and sixty five of them responded with response rate 89%. The results illustrate that, the financial capability of the contractors, the reputation of the clients, the financial capability of the clients, the financial values of the project, the availability of construction raw materials in the local markets, and the stability of the construction industry were the most critical factors affecting the contractors bid-no bid decisions. This study suggests that contractors and clients should improve their financial systems and capabilities in order to stay in business.

Rural Development in Finland: Revival of a Natural Resource Sectors Perspective

Cumulative economic forces drive societal structures toward centralization, more intensive primary production, and unbalanced regional development. Ongoing structural change has accentuated the disparity between lagging and prosperous Finnish rural areas and altered the role of natural resource sectors. Along with their primary task of providing society with food, renewable energy, and raw materials for construction, alternative forms of products and services, as well as improving attractiveness of rural areas as places of residence, work, and recreation, can be exploited in securing rural viability and in attenuating disparity among rural areas. This article reviews the development in Finland in the light of available statistical data. The potential of the natural resource sectors to contribute to endogenous rural development is discussed in the context of rural policy and natural resource strategies and by paying attention to the differences among rural areas.

Factors affecting the bid/no bid decision in the Palestinian construction industry

PurposeThe purpose of this paper is to identify and rank the factors that affect the bid/no bid decision according to their relative importance from the perspective of the contracting parties operating in the Gaza Strip, Palestine.Design/methodology/approachThe objectives of this research were investigated through a postal questionnaire, which covered a randomly selected sample of 63 contractors, 29 clients and 13 consultants operating in the construction industry in the Gaza strip. The questionnaire was structured based on related literature, the pilot study and actual factors affecting bidders' decisions to bid or not that arise from special conditions in the Gaza Strip. A total of 78 factors that affect the bid/no bid decision were identified. These factors were then ranked according to their relative importance to contracting parties operating in the Gaza Strip, Palestine.FindingsThe results illustrate that the financial capability of the contractors, the financial capability of the clients, the financial values of the project, the due date of the payments, the availability of construction raw materials in local markets, and the stability of the construction industry were the most critical factors affecting the bid/no bid decision, as agreed by all respondents.Originality/valueThe paper provides supportive practical solutions for contractors, clients and consultants to enhance and improve bidding decisions. It is recommended that clients and consultants consider the financial capabilities, technical capabilities and staff competencies of the contractors during the awarding stage, and not simply focus on the lowest bid.

Castles from the Rożnów and Czchów lakes area as geotouristic lapidarium and role of the Istebna Sandstones in their construction

On the Roznow Foothils area, at the Roznow and Czchow artificial lakes, a few usually ruined castles are located. This historical and recently monumental defensive objects emerged mainly in the Middle Ages. These Castles, are located on exposures of the Upper Cretaceous Istebna Beds. The Istebna Sandsones constitutes also natural local construction raw materials. The Istebna Beds are involved in the structure of the Silesian Nappe, one of the main Outer Carpathian tectonic units. The original walls of castles with their geological enclosing are geoturistic attractions of the Roznow Land. They could be also a kind of lapidarium. In their walls are exposed specimens of the sandstone lithotypes typical for the Istebna Beds.

Solidification/Stabilization Disposal of Medical Waste Incinerator Flyash Using Cement

Medical wastes in Malaysia are incinerated with the ash disposed into landfills. We studied alternative treatments of medical waste incineration fly ash by solidification/ stabilization (S/S) using three types of cement: OPC, MSC and GGBS. The effect of additives - activated carbon (Ac) and rice husk (Rh) on metal retention was also studied. Metal leaching was quantified using TCLP, JLT-13 and ANS 16.1 (modified). Compressibility strength was measured by ASTM (Compressive Strength of Hydraulic Cement Mortars). Ash contained high concentrations of Al, Ti, Fe, Zn, Cr, Fe, Pb and Cu and most of these elements leached heavily if not treated. TCLP and JLT-13 quantification showed all cement types prevented metal leaching. Solidification with Ac and Rh respectively further reduced leached metals by 10 and 20%, resapectively. ANS 16.1 (modified) showed leach rates between 10-4 and 70 cm/day. Leachability Index rates exceeded 6.0, indicating low leaching. Compressive strength increased as cement loading and curing days increased. OPC showed higher metal retention efficiency and compressive strength. Estimated costs for S/S treatment are higher than current disposal costs. However, S/S products could be used as raw materials for construction. 

Mechanical behavior of recycled lightweight concrete using EVA waste and CDW under moderate temperature

Many benefits can be achieved by using recycled waste as raw material for construction. Some of them are the reduction of the total cost of the construction, the reduction of the consumption of energy and the decrease in the use of natural materials. The construction sector can also incorporate the waste of the other industries, like the waste of the shoes industry, the Ethylene Vinyl Acetate (EVA). EVA aggregate is obtained by cutting off the waste of EVA expanded sheets used to produce insoles and innersoles of the shoes. In this work two types of recycled aggregate were used - construction and demolition waste (CDW) and EVA. The aim of this work was to study the influence of the use of these recycled aggregates, as replacement of the natural coarse aggregate, on mechanical behavior of recycled concrete. The experimental program was developed with two w/c ratio: 0.49 and 0.82. Four mixtures with produced with different aggregates substitution rates (0, 50%EVA, 50%CDW and 25%EVA-25%CDW), by volume. Compressive tests were carried out to evaluable the influence of recycled aggregate on strength, elastic modulus and Poisson coefficient. In addition, it was evaluated the effect of the moderate temperatures (50, 70 and 100º C) on stress-strain behavior of concretes studied. The results demonstrated that is possible to use the EVA waste and RCD to produces lightweight concrete. The influence of temperature was more significant only on elastic modulus of the recycled concrete with 50%EVA.

O Mineral Nosso de Cada Dia: Tema para Formação de Habilidades Previstas nos PCN

O Museu de Geociências/IG da Universidade de Brasília vem desenvolvendo o programa “Mineral Nosso de Cada Dia”, destinado a estudantes da educação básica, oferecendo a oportunidade de compreender a importância das substâncias minerais no cotidiano, através das três oficinas “Mineral Nosso de Cada Dia”: a “Casa”, “Transportes – veículos, combustíveis e vias” e “Artes”. Em cada oficina os estudantes são indagados sobre os materiais que constituem e/ou fazem funcionar a casa, os veículos e vias de transporte e as obras de arte, bem como pelas respectivas matérias-primas e os tipos de energia que as formam e transformam. Utilizando informações obtidas em revistas, livros, mapas e nas etiquetas das amostras do Museu, os estudantes verificam a distribuição das matérias-primas minerais no espaço e no tempo. Manuseando os conjuntos de amostras, os estudantes são envolvidos em atividades práticas de descrição e identificação das rochas e dos minerais comumente usados como matéria-prima para edificações, veículos, combustíveis, vias de transporte e de obras de arte. As atividades, utilizando a linguagem básica específica, desenvolvem a capacidade de leitura, audição e de representação gráfica, servem para motivar os estudantes a ler e escrever sobre as Ciências Naturais e a aprender com o conhecimento científico. Assim, através do aprendizado real e contextualizado, o programa “Mineral Nosso de Cada Dia” contribui para a melhor formação dos estudantes da educação básica, desenvolvendo habilidades e competências para o estudo dos materiais naturais, subsidiando a construção do Modelo Referencial do Meio Físico (matéria, energia, tempo e espaço) e valorizando o conhecimento científico como fator de desenvolvimento e bem-estar.

Construction raw materials in Timor Leste and sustainable development

Abstract Timor Leste is the newest and one of the poorer nations in the world. One of its main challenges that could lead to poverty reduction is the reconstruction and maintenance of the infrastructures that were almost completely destroyed after its independence referendum. To achieve this, there is an imperative need for construction raw materials in a country where the extractive industry is scarce and artisanal. Available geological studies deal with the island’s geology and tectonic evolution or its oil and gas potentialities. Very few broach other geological resources. A general study of the country’s territory demonstrates that Timor Leste possesses large resources in clays, limestones and sand and gravel, which can support small- to large-scale raw material extractive industries. Some selected areas have been the target of more detailed study: Venilale and Aileu, with resources for structural ceramics and whiteware respectively, and Beheda, where a crinoid-rich limestone crops out, with potential for usage as ornamental stone. These resources are suitable for non-sophisticated small-scale mining operations that should be able to accomplish environmental and social liabilities. No public policy exists for the management of these mineral resources, which is essential for the sustainable development of Timor Leste.

Local discourse and global research: The role of local knowledge

Detailed analysis of transcripts is a time-honored practice among linguistic ethnographers. In contemporary research, however, interactions among global forces distant from ethnographic sites are critical for analysis and explanation, as is the fact that multiple sites must be covered. Ethnographers' interests, pragmatic relevance, and personal deixis militate against the ability of site-specific talk to serve as raw material for construction of the representations of those distant global forces. In this article, local discourse, as manifested in ethnographic oral-history interviews, is viewed first as a test of the impact of those global forces. Second, the talk is a construction that can be explained in terms of those forces' linkage with global representations. Finally, the concept “fractal” is suggested as a possible way to show such links.NOTE: Support by NIH/NIDA grant no. DA-10736 is gratefully acknowledged.

The building stones of ancient Egypt – a gift of its geology

Building stones and clay-rich Nile mud were ancient Egypt's main raw construction materials. While the mud was easily accessible along the Nile river valley, the immense quantities of the different stone materials used for construction of the famous pyramids, precious temples and tombs needed a systematic quarrying organization, well arranged transport logistics over extreme distances and a high standard of stone masonry. The petrography, occurrence, and main applications of the 11 most popular stone types used in ancient Egypt are described in this contribution. Rough estimates of the scale of this mining activity, based on the volume of many different ancient quarry sites, all over Egypt, reveal that the monuments known today represent only a small fraction of the amount of building stones mined during the long, ancient Egyptian history.

Controls and incentives: A framework for the utilisation of bulk wastes

This paper examines the economic, legal and environmental parameters within which the utilisation of bulk wastes takes place. Using the example of construction and demolition (C&D) wastes in a number of European countries the paper demonstrates that the amounts of waste reutilised and the uses to which those wastes are put are dependent on both regulatory conditions and the level of economic incentives available. The effective regulation of waste is regarded as essential in minimising the level of C&D which are “lost” to the reutilisation stream. The taxation of raw materials for construction will also be addressed in determining the contribution that this might make to the reutilisation of bulk wastes.

The application of clay minerals in ceramics

Deriving in ancient Greece as keramikos, the term potters clay was only reconfirming the recognition of clay as man's earliest utilitarian raw material. Clay is no doubt man's first manufacturing and construction raw material and fortunately, through the miracle of fire, the first lasting chronicler of his own origin and early history. Oddly enough, millennia later, the material still occupies leading positions in the construction and manufacturing areas with each generic end-use accounting annually for about one billion dollars of salable product in the U.S. alone. Needless to say, clay ceramics are proven products. The longevity of clay in the ceramics industry stems in part from its variable and some times unique physical and chemical properties and in part to its ubiquitous occurrence and relatively inexpensive produced value. Clay properties of interest to the ceramics industry are plasticity and moldability, of course, but also chemistry, color, refractoriness, solubility and corrosion resistance, electrical properties and the many possible variations on these and other properties afforded by the essentially two-dimensional morphology of the individual clay platelets. In addition to construction (brick, tile, sewer pipe, cement, fiberglass, roof granules, paint, etc.) and manufacturing (refractories, kiln furniture, sanitary ware pottery and dinnerware) clays are used in the calcined form as fillers, carriers, extenders and grogs. Chemistry, because of its basic relationship to both the chemical and physical properties of clay, has been the subject of continuous studies over the past few decades and is responsible for most of advances in processing which have taken place. Color body removal and the elutriation of objectionable salts have led to more or less sophisticated slurrying and the beneficiation which this medium affords. In particular, the water washing, first initiated by the kaolin industry and now extended to ball clays, and high-energy magnetic filtration have noticeably improved the quality of clay and broadly expanded its market in the ceramics industry. At the present time, ceramics markets are under pressure in several areas. Refractories have followed the downturn in American steel production. Although stabilizing, this industry continues at reduced levels which threatens to become the new norm. Likewise, dinnerware and tile production in the U.S. have declined because of foreign competition.

産業連関表による建築物の評価 : その1.省エネルギービルと一般事務所ビルの比較

Basic sector classification and regional input output tables were applied to analyze investments in construction and operation of an energy conserving office building (3 776 m^2) and a conventional office building, in order to obtain influences upon various industrial sectors and final consumption of raw materials. Consumption of raw materials for construction of an energy conserving building is same as that of a conventional office building, however the final demand for secondary product sectors is larger. Investment in energy sectors due to operation of the energy conserving building is 33 % compared with the conventional office building and the final consumption of raw materials, 45 % , because of influences due to investment in service sectors for building maintenance. Regional input output tables estimate the influences upon various industrial sectors in various areas. Assuming that construction site is Kanto, Chubu or Kinki area, 60-70 % of the final demand due to the construction is supplied in the construction site, however Hokkaido, Shikoku or Okinawa, between 30 and 50 %. The energy conserving building which is provided with higher technology facilities tends to concentrate the final demand in Kanto area, especially concerning sectors of metal and electrical products.