Demand For Construction Materials Research Articles

The properties and formation mechanisms of eco-friendly brick building materials fabricated from low-silicon iron ore tailings

The volume of tailings discharged worldwide from iron ore smelting processes (i.e., iron ore tailings) has increased dramatically in recent years, and the disposal of this waste poses a substantial ecological threat to soil, and surface and sub-surface water. This threat can be alleviated to a large extent by employing iron ore tailings to fabricate brick building materials, while also effectively meeting the large demand for construction materials. The present paper discusses the preparation of eco-friendly bricks using fine-grained low-silica iron ore tailings and a non-cement curing agent system as the primary raw materials, and a triethanolamine hardening accelerator and a stearic acid emulsion waterproofing agent are also employed as minor components. We first evaluate the effect of the waterproofing agent content on the compressive strength and water resistance of the resulting products. In addition, the phase composition, chemical structure, and microstructure of the products are analyzed via X-ray diffraction, Fourier transform infrared spectroscopy, and scanning electron microscopy to explore the formation mechanism of the brick products. The analyses demonstrate that hydrated calcium silicate gel and ettringite formed in the curing process are strong binders. The water resistance and compressive strength of the product was optimal when the waterproofing agent and curing agent were 0.3 wt% with an initial curing temperature of 60 °C. The compressive strength and saturated compressive strength of the optimally formed brick products after curing for 28 d were 27.2 MPa and 24.3 MPa, respectively. The other physical properties and durability conform to the Chinese JC/T422-2007 standard for unfired bricks made of tailings.

English

In recent times, rapid changes in buildings and infrastructural development have increased demand for construction materials. Ndarugu quarries located about 35 km north of Nairobi CBD are among the main sources of building materials in Kenya. The visible evidence of stone mining are the post-quarried sites scarred along the Ndarugu ridge, which has altered the original land condition and continues to affect people who live in surrounding areas. The objectives of the current study were (i) to assess the perception of stone quarry landowners on economic and social impacts of stone quarrying and (ii) to assess status of post-quarry land and factors influencing rehabilitation efforts. Data was collected through interviews guided by questionnaire undertaken along a transect parallel to river Ndarugu ridge where quarrying is concentrated, by sampling alternate homestead and company head. The data collected were analysed using frequencies and association between variables. From the analysis, majority of the respondents (47.1%) were small-scale farmers while 78.8% earned less than KSh. 30,000 (300 USD) per month. Quarrying was in progress in many of quarry sites, while the oldest was quarried 28 years ago. Creation of employment opportunities and opening up of the interior areas for business development were perceived as the main positive impacts of quarrying while influx of new migrants and dust pollution were perceived as the main negative impacts of stone-quarrying. Backfilling with local soil was main environmental repair method identified although a large percentage of the quarried land (95.2%) had not been repaired fully. Crop farming and trees planting were the most preferred post quarry land use. Lack of financial support services and lack of a compulsive legal framework were perceived as main limitations to environmental repair. Matching the quarrying activities with effective landscape management strategies to reduce negative impacts is recommended.   Key words: Land owners, stone quarrying, quarrying impact, rehabilitation method, post quarry land use.

Bio-based construction panels for low carbon development

Over the last years there has been an increase in demand for construction materials that fulfil the high-level energy efficiency requirements while ensuring reduced impact on environment compared to the traditionally used materials. The hemp-lime concrete as a self-bearing thermal insulation material with low thermal conductivity and neutral CO2 emissions is one of such materials that can ensure it. However due to its limited strength the use of this material is problematic in projects of industrial scale. Magnesium oxychloride binders are of considerably higher strength level and better bio-compatibility compared to the lime-based binders, hence in this research the former were used in combination with a hemp filler to produce composite materials to be used in production of construction panels for industrial scale. These panels consist of an outer and inner border layer and a middle thermal insulation layer, that can be provided by magnesium-hemp concrete with varied amount of the binder added. To evaluate impact on environment of such panels, the Life cycle assessment was performed, analyzing amount of CO2 produced by them and comparing it to the traditionally used materials with similar thermal transmittance properties. Results of the research showcase that the magnesium-hemp concrete can be used in production of bio-based construction panels because strength of their outer layers can reach up to 1.2 MPa at 450 kg/m3 density and that of the inner layer – 0.06 W/m·K at 200 kg/m3 density. It was proved in the research that the magnesium-hemp panel represents reduced impact on environment because a panel, 370 mm thick, that ensures the U value of 0.18, emits 12.7 kg/CO2 eq. m2, that is 5 times less compared to the traditionally used materials.

Natural fiber textile reinforced bio-based composites: Mechanical properties, creep, and environmental impacts

Abstract With rising demand for construction materials, so too grow the environmental impacts associated with their production. This trend has raised interest in the development of bio-based composites as environmentally favorable alternatives to conventional materials. Yet, a greater understanding is needed of both the mechanical properties of bio-based composites and their long-term properties, particularly their creep deformation. This work examines the use of a bio-derived polymer matrix reinforced with three types of natural fiber textiles. The mechanical properties and the creep deformation of these composites are characterized showing a dependence on textile type and orientation. Application of time-stress superposition to capture creep behavior through accelerated testing is examined and is shown to be a promising means of capturing long-term creep deformation. The results of this work show that the textile reinforced bio-based composites studied have similar mechanical properties to several conventional construction materials. Further, because time-stress superposition is shown to capture creep behavior of most of the composites studied, this method might prove to be a means for expediting the collection and analysis of creep data for bio-based composites. Finally, combined comparisons of mechanical properties and environmental impacts of these bio-based composites suggest these materials could offer environmentally favorable alternatives to conventional materials.

Proyección de la demanda de materiales de construcción en Colombia por medio de análisis de flujos de materiales y dinámica de sistemas

This article provides an estimation of the future demand of construction materials in Colombia and necessary minerals to produce them by using systems dynamic and analysis of materials flows. Through the analysis of materials flows the amount of minerals required for the production of cement and concrete are determined. Required production of cement and concrete is estimated through a model of systems dynamic, which is adjusted with data from DANE construction census. Results indicate that, disregarding the secondary offer of materials, 176.9 million tons of ground aggregates, river sand, gray cement, dead rock, and cooked ceramic would be required. Manufacture of cement and concrete would require 15.4 million tons of lime, 14.9 million tons of gravel, 14.1 million tons of gypsum, and 13.3, 9.7, and 9.3 million tons of clay, iron minerals, and sand, respectively.

Fastening application in concrete using recycled tunnel excavation material

The demand for construction materials at tunnel construction sites is naturally very high. Thus, tunnel excavation material is increasingly used as a substitute for conventional mineral aggregates. Excavation material is not a standard product in terms of geometric, physical, and chemical properties of the rock as its quality is changes during tunnel driving depending on the geology and excavation method. By using this material as aggregate for concrete, the concrete obtains its characteristic properties. Certain concrete properties do not only influence the construction material itself but also fasten the elements that are assembled to the structural concrete. In this case, experimental validation of the usability of this special concrete for postinstalled anchorages and the effectiveness of different fastening systems are required. Therefore, investigations using various postinstalled anchor systems in different inner shell concrete types made of recycled aggregate (in this context, Bündner schist from the Brenner Base Tunnel) were performed in this study to obtain an assessment of the applicability of these systems in concrete with aggregate made of tunnel excavation material.

The Brick-making Industry in Kuala Lumpur in the Late Nineteenth Century

Kuala Lumpur was primarily a mining centre in the nineteenth century, but there were other significant economic activities as well. As the city grew, so did the demand for construction materials. Although small compared with mining, the brick-making industry helped change Kuala Lumpur from a small village to a substantial city. This article explains how brick-making developed, and examines its significance.

Experimental Study on the Behaviour of Modified Concrete

There is great demand for construction materials due to Infrastructural development across the world. Concrete is one of the widely used construction material in the world. Concrete preparation requires ingredients like cement, aggregates, water and admixture(s). The problems of concreting in cold weather arises from the action of frost on fresh concrete. When water in wet concrete freezes, it increases the overall volume of concrete. As there is now no water available for hydration of cement, setting and hardening of concrete are delayed. This damages the concrete and makes it unfit for use. An accelerator admixture is used to accelerate the rate of hydration (setting) and strength development of concrete at an early age. This paper investigates the behaviour of concrete using accelerator admixture. The study is set up to compare 3 day , 7 days and 28 day compressive strength, flexural strength and tensile strength of commixtured concrete with plain concrete. This paper also focuses on the assessment of the role of accelerator admixture in helping the rate of gain of early strength and the harmful effects of the accelerator on concrete properties. The optimum percentage of accelerator that could be used without harming the properties of concrete is also arrived at.

Case Study: LCA Methodology Applied to Materials Management in a Brazilian Residential Construction Site

The construction industry is increasingly concerned with improving the social, economic, and environmental indicators of sustainability. More than ever, the growing demand for construction materials reflects increased consumption of raw materials and energy, particularly during the phases of extraction, processing, and transportation of materials. This work aims to help decision-makers and to promote life cycle thinking in the construction industry. For this purpose, the life cycle assessment (LCA) methodology was chosen to analyze the environmental impacts of building materials used in the construction of a residence project in São Gonçalo, Rio de Janeiro, Brazil. The LCA methodology, based on ISO 14040 and ISO 14044 guidelines, is applied with available databases and the SimaPro program. As a result, this work shows that there is a substantial waste of nonrenewable energy, increasing global warming and harm to human health in this type of construction. This study also points out that, for this type of Brazilian construction, ceramic materials account for a high percentage of the mass of a total building and are thus responsible for the majority of environmental impacts.

Sawnwood Substitution in Dar es Salaam, Tanzania and its Linkage to Environmental Conservation

There is an increased trend of global awareness and discussions on the contribution of building designs and materials in global warming and greenhouses gases emissions. The use of wood materials in the construction sector is also increasing hence linked to forest industries and conservation, building sector, global warming and global climate change. The construction sector contributes directly and indirectly to environmental degradation and greenhouses gases emissions. With the current global awareness on climate change and adaptation, the substitution of wood products in the construction sector in Tanzania is inevitable. Despite its significant growth, the substitution of sawnwood by different alternatives in Tanzania is not well examined. Therefore, this study forecasted the substitution of sawnwood for year 2016, 2021 and 2026 for Dar es Salaam using income elasticity of demand to explain the effects of these substitutions to the environment. The consumption of sawnwood in none storey buildings, medium category and high category buildings were 2.69 m3, 3.1 m3 and 5.3 m3 respectively. In 2012, Dar es Salaam consumed a total of 8,706.9 m3 of sawnwood for doors and window frames in about 2878 new buildings. Kinondoni district consumed 42.2%, Ilala district 34.8% and Temeke district 23% of the total sawnwood. The per capita sawnwood consumption for building in Dar es Salaam in 2012 was 2.7 m3 while for aluminium was 46.2 m2. Windows showed high substitution of sawnwood compared to doors with aluminium being the main substitute material. The forecasted per capita consumption of sawnwood and aluminium materials for buildings in 2026 was 3.4 m3 and 86.8 m2 respectively. Sawnwood consumption in none storey buildings is increasing as a results of high rate of urbanization and economic growth hence increased number of middle-income population which causes an increased demand and construction of houses for residential purposes. The increased demand for construction materials have negative impacts to the environment where these materials are harvested. We recommend further research on the effects of substitution of sawnwood and the promotion of lesser-known and underutilized sawnwood species to strengthen wood industry in Tanzania due to the current high demand of sawnwood and high substitution rates.

Why highly polluting methods are used to manufacture bricks in Bangladesh

Brick kilns in Bangladesh use inefficient coal burning technology that generates substantial air pollution. We investigated the incentives of stakeholders in brick manufacturing in Bangladesh to help inform strategies to reduce this pollution. A team of Bangladeshi anthropologists conducted in-depth interviews with brick buyers, kiln owners, and Department of Environment employees. Brick buyers reported that bricks manufactured in traditional kilns worked well for most construction purposes and cost 40% less than bricks manufactured in more modern, less polluting, kilns. Brick kiln owners favored approaches with rapid high return on a modest investment. They preferred kilns that operate only during the dry season, allowing them to use cheaper low-lying flood plain land and inexpensive seasonal labor. The Department of Environment employees reported that many kilns violate environmental regulations but shortages of equipment and manpower combined with political connections of kiln owners undermine enforcement. The system of brick manufacturing in Bangladesh is an economic equilibrium with the manufacture of inexpensive bricks supplying the demand for construction materials but at high cost to the environment and health of the population. Low-cost changes to improve kiln efficiency and reduce emissions could help move toward a more socially desirable equilibrium.

Use of bio-briquette ash for the development of bricks

The issue of the ever increasing demand for construction materials and waste management has created a need for the development of sustainable materials with the appropriate utilization of wastes. This paper presents the study of the use of bio-briquette ash (BBA) for the development of bricks. Physico-chemical property investigations for a BBA sample were conducted, and the sample was found to be suitable as an alternative raw material for the partial substitution of sand. For the development of the bricks, BBA was added according to the partial replacement method (5–55%) for sand, keeping the cement percentage constant. Six compositions were prepared with 10 wt% variations. The developed product was tested according to the Indian Standards (IS) for density, compressive strength, water absorption and efflorescence along with the durability and thermal properties. The effect of the addition of the BBA on the brick properties was investigated. Thirty-five weight percent BBA, 55 wt% sand and 10 wt% cement were the optimal mix composition for the developed BBA bricks that fulfilled the desired properties of IS. The developed BBA bricks were found to have better mechanical and thermal properties and were more economical than commercially available fly ash and clay bricks. The developed bricks are recommended for non-load bearing walls.

PARTIAL REPLACEMENT OF COARSE AGGREGATES BY EXPANDED POLYSTYRENE BEADS IN CONCRETE

With the increase in demand for construction materi als, there is a strong need to utilize alternative materials for sustainable development. The main objective of this investigati on is to study the properties, such as compressive strength and tensile strengths of lightweight concrete containing Expanded Polystyren e (EPS) beads. Its properties are compared with th ose of the normal concrete i.e., without EPS beads. EPS beads are used as par tial replacement to coarse aggregates. The results showed that the amount of polystyrene beads incorporated in concrete influenc es the properties of hardened concrete. At 28 days , it was found that compressive strength of 5%, 10%, 15%, 20%, 25% and 30% EPS inco rporated concrete strengths were 91%, 77 %, 71%, 6 3%, 57%, and 45%, respectively when compared to concrete with no EPS case.

Sustainably managing natural resources and the need for construction materials in Pacific island countries: The example of South Tarawa, Kiribati

AbstractThe growing demand for construction materials in South Tarawa, a remote atoll in the South Pacific, provides an example of the environmental and social challenges associated with the use of non‐renewable resources in the context of small island countries threatened by coastal erosion and climate change. In many small Pacific island countries, the availability of construction materials is limited, with the majority mined from beaches and coastal reefs in an unsustainable manner. Growing demand for construction aggregates is resulting in more widespread sand mining by communities along vulnerable sections of exposed beach and reefs. This has serious consequences for coastal erosion and impacts on reef ecosystem processes, consequences that cannot be easily managed. Construction materials are also in high demand for infrastructure projects which are financed in part with support from international development agencies and donors. This paper reviews the various challenges and risks that aggregate mining poses to reefs, fish, and the coastal health of South Tarawa and argues that the long term consequences from ad hoc beach/reef mining over large areas are likely to be far greater than the impacts associated with environmentally sustainable, organized extraction. The paper concludes with policy recommendations that are also relevant for neighbouring island countries facing similar challenges.

The ShakeOut Scenario: Meeting the Needs for Construction Aggregates, Asphalt, and Concrete

An Mw 7.8 earthquake as described in the ShakeOut Scenario would cause significant damage to buildings and infrastructure. Over 6 million tons of newly mined aggregate would be used for emergency repairs and for reconstruction in the five years following the event. This aggregate would be applied mostly in the form of concrete for buildings and bridges, asphalt or concrete for pavement, and unbound gravel for applications such as base course that goes under highway pavement and backfilling for foundations and pipelines. There are over 450 aggregate, concrete, and asphalt plants in the affected area, some of which would be heavily damaged. Meeting the increased demand for construction materials would require readily available permitted reserves, functioning production facilities, a supply of cement and asphalt, a source of water, gas, and electricity, and a trained workforce. Prudent advance preparations would facilitate a timely emergency response and reconstruction following such an earthquake.

It is all about livelihoods: A study of women working in stone chip production in Cape Coast Municipality, Ghana

Outcrops of granite in several localities in the urban and peri-urban fringes of Cape Coast Municipality in Ghana have led to stone chip production becoming a major livelihood strategy for vulnerable and poor women. Previously, this work was primarily carried out by men, but today female workers dominate the workforce, and increasingly it is seen as a way for women to seek a viable living in conditions which are otherwise marginalized and poor in economic terms. The demand for stone chips has increased with the high demand for construction materials for housing in the town of Cape Coast. However, the women's choice of livelihoods strategy (stone cutting) prevents them from gaining other experiences from more lucrative processes. Hence, as stone cutters, they are disadvantaged within the increasingly commercialized economy. Against this background it can be argued that a feminization of poverty is taking place. The data for the study were derived through structured and unstructured interviews, focus group discussions and direct observation, and analysed according to a livelihoods framework.

O uso de sistema de informações geográficas na priorização de áreas para aproveitamento mineral de saibro em áreas degradadas, Ubatuba, SP

No município de Ubatuba existem 116 áreas degradadas pela mineração, que foram avaliadas e classificadas por meio de um Índice de Aproveitamento Mineral desenvolvido no Sistema de Informações Geográficas SPRING. O referido índice leva em consideração variáveis topográficas e variáveis relativas a restrições de uso e ocupação do solo e legais. Os resultados mostram a classificação de seis áreas como sendo de muito alto potencial para aproveitamento e 35 com potenciais de alto a médio. Na primeira etapa de avaliação, o cálculo de volume de material disponível foi efetuado de forma semi-automática por meio de rotina computacional existente no programa SPRING. Em seguida foram aplicados critérios para correção do volume total calculado, que incluíram: a) correção da geometria das curvas de nível desatualizadas; b) índices numéricos atribuídos a restrições sociais e legais e obtidas por meio de operações topológicas. Os resultados foram divididos em cinco intervalos numéricos do Índice de Aproveitamento Mineral que indicam áreas prioritárias para a implantação de lavras de saibro, promovendo de um lado a elaboração e custeio de planos de recuperação de áreas já degradadas, e de outro, o atendimento da demanda local de saibro sem a necessidade de abertura de novas frentes de lavra em áreas melhor preservadas.

Mineral resources and their economic significance in national development: Bangladesh perspective

Abstract Modern urbanization, industrialization, transportation and communication systems are the achievements of worldwide sustainable mineral resource development and their proper utilization in various sectors. Sustainable mineral resources have played, and are still playing, a vital role in shaping the modern civilized industrial world. This means that the sustainable socio-economic infrastructure of any country is an indication of its richness in natural resources, its technological know how, its ability to explore and exploit mineral resources, and, finally, its wisdom in utilizing those resources properly in the development activities of the nation. In development activities, countries of the developing world are generally far behind compared with countries in the developed world. This is mainly due to a lack of adequate natural resources, properly educated human resources and good socio-economic conditions. Although Bangladesh is a small country, it has a number of mineral resources such as natural gas, oil, coal, hard rock, limestone, white clay, glass sand and mineral sand. At present, natural gas is the only mineral commodity significantly contributing to the national economy. More than 90% of the country’s energy needs are met by gas, total reserves of which are 21.35 trillion cubic feet (TCF) and 12.43 TCF, respectively. Huge reserves of hard rock (granodiorite, quartzdiorite, gneiss) and coal in northwest Bangladesh will help, in the near future, to meet the growing demand for construction materials and energy for the ever-growing population. Total coal reserves are 1753 million tons (MT), the market value of which is more than US$110 billion. Hard rock reserves are 115 million tons, valued at over US$3 billion. Fully fledged extraction of these resources would help to alleviate the country’s poverty through industrialization. It is expected that coal will soon be extracted on a commercial basis, of which 70 to 80% will be used in power generation. The mineral resources so far found in Bangladesh are meagre in comparison to its high population. To meet the growing demand of the population, more mineral resources need to be discovered and developed, otherwise sustainable development cannot be achieved. However, it is difficult for developing countries like Bangladesh to carry out the necessary activities for exploration and exploitation of hidden mineral resources without foreign assistance. This is a major drawback for Bangladesh. To progress towards an endurable sustainable society, a nation such as Bangladesh must give priority to the development of its existing mineral resources, which can play a major role in helping to reshape the country’s socio-economic infrastructure.

Austria proposes system for leasing chemicals

The world’s environmental summit’s main goal is to reduce GHGs (Greenhouse gases) by promoting sustainable developments and to save the mother earth from Ozone depletion which is mainly responsible for Global Warming. Due to increasing population which leads to more urbanization & industrialization, there has been a rapid increase in construction activities. Hence there is lot of demand for construction materials mainly cement which releases one Ton of CO2 per Ton cement manufactured. To overcome this issue construction industry is obligated to explore an efficient sustainable building material to substitute for conventional Portland cement concrete. Geo-polymer concrete is an emerging material replaces cement completely and manufactured using secondary cementitious materials like Fly ash, GGBS, Metakaoline, Bagasse Ash, Silica Fume etc., This paper is concerned with manufacturing of geopolymer concrete with a lower concentration of alkaline activated solution such as NaOH & Na2SiO3 as activators and Fly ash & GGBS as base materials. Investigations are made to find both fresh & hardened properties with different combinations of these materials along with Natural sand and M-sand as a comparative study to produce M30 to M40 grade of concrete which is extensively used in all types of structural applications. This paper explores the behaviour of Geopolymer concrete in its fresh state for various combinations of Fly ash & GGBS. Early strength gain is noted even at ambient curing along with experimented results of different basic hardened mechanical properties. The carried work mainly attempts to promote Geo-polymer concrete with M-Sand in the place of normal concrete is an efficient way of keeping sustainability aspect contributing towards global warming.

Impact on the Coastal Environment of Marine Aggregates Mining

The higher demand for construction materials and the depletion of land sources, coupled with sterner environmental restrictions, led suppliers to turn to the sea, particularly to the near-shore areas. Several of these mining operations are illegal, many are damaging for the coastal and off-shore environment, some are threatening coast lines including in such sensitive areas as the coral reefs. A case study is examined for Australia.