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The colonisation of building materials by microorganisms is the first step in terms of a subsequent biodeterioration and an occurrence of potential building-associated health hazards. Contrary to many studies to date, focusing mainly on old buildings with symptoms of biocorrosion, this research focuses on the bioreceptivity of selected unused building materials and the factors determining the intensity of their colonisation. The experiments were carried out in parallel in India and Poland, with the use of indigenous microflora from a given region. They revealed the similar dynamics of the microbial multiplication in concrete and plasterboard and the extreme intensity of the process: after only 10 weeks under favorable conditions, the number of bacteria and fungi reached 107 CFU/g of dry weight of the material. The stimulation of microbial growth by individual environmental factors was slightly different in Indian and Polish studies: in India, the strongest stimulating factor was the periodic increase in humidity, while in Poland, the highest intensification of growth was observed in samples enriched with organic matter. Mould biodiversity turned out to be higher in India, although some types of fungi common to both regions were isolated. [ABSTRACT FROM AUTHOR]

The total primary embodied energy (EE) and carbon dioxide (CO2) emissions (ECO2e) of geopolymer concrete (GPC) in high-rise (60 m height) residential buildings located at Chennai city, India, were carefully examined in this study. The buildings were analysed and designed with the same aspect ratio and loading with two structural systems; Reinforced concrete (RC) framed and Shear wall type. The computation was performed for floor area, building volume, and concrete quantity. The results show that for the same grade of concrete, compared with conventional concrete (CC), GPC's EE is reduced by 46%, ECO2e is reduced by 42%, and the cost is reduced by 7%. The primary energy consumption (EET) and CO2 emissions (ECO2eT) towards material transportation in GPC shear wall and framed structures are 8% lower and associated cost is 22% cheaper than CC buildings. Compared to CC, the total primary EE and ECO2e of GPC RC shear wall and framed buildings are 46 and 55% lower, respectively. From the study, it has been observed that GPC is more environmentally beneficial than that of using CC in high-rise structures. [ABSTRACT FROM AUTHOR]

• Novel analysis of attenuation the growth of Aspergillus tamarii on concrete using radiation in the field of conservation of heritage building. • UVC and gamma irradiation decreased the leaching of calcium ions from concrete when infected with A. tamarii. • Increase in compressive strength of concrete cube was observed to be the most in irradiated cubes. • Effect of A. tamarii and low dose radiation led to less deterioration of concrete (except higher dose) than only exposure to A. tamarii. The conservation of concrete-based deteriorated heritage buildings is a big challenging issue worldwide including in India. This study focused on to prevent fungal biodeterioration in concrete using UVC and gamma radiation. M20 graded concrete cubes (5 cm × 5 cm × 5 cm) were infected with Aspergillus tamarii , which was isolated from a 200 years old historic heritage building. M20 signifies a mixture of cement, sand and aggregate (1:1.5:3), made in such a way that the concrete cube has a compressive strength of 20 N/mm2 when examined after 28 days of curing. The fungal growth appeared clearly as calcium oxalate crystals in the Scanning Electron Microscope (SEM) photographs. Several doses of UVC and gamma radiation were applied on concrete cube. The changes in concrete properties were examined after 30 days in terms of weight, compressive strength, Fourier Transform Infrared Spectroscopy (FTIR) and micro Energy Dispersive X-ray Fluorescence (EDXRF). The results exhibited that compressive strength of control (non-infected and non-irradiated), biodeteriorated (infected), UVC (625 µw/cm² × 300 s) and gamma (0.5 KGy) irradiated infected (inhibition) concrete cubes were 19.74 ± 0.46, 18.88 ± 0.43, 20.20 ± 0.34 and 19.93 ± 0.20 N/mm2 respectively whereas negligible weight losses were observed for inhibition cubes compared to biodeteriorated ones. Calcite (1400, 874 and 705 cm−1), one of the major functional band present in concrete became weak after getting infected by Aspergillus tamarii and strong for inhibition samples irradiated with the above doses. The EDXRF analysis exhibited that mass percentage of calcium ions of the biodeteriorated concrete cubes (49.88 ± 0.65%) was lower than that of UV (75.75 ± 0.16%) and gamma (70.95 ± 0.30%) irradiated infected or inhibition concrete cubes. Altogether, the efficacy of the recommended inhibitory dose of ultraviolet and gamma radiation against concrete deterioration in the field of conservation of heritage building was observed to be positive. [Display omitted] [ABSTRACT FROM AUTHOR]

This study explores the feasibility of utilizing Waste Brick Powder (WBP) and fly ash as substitutes for cement in concrete, addressing growing environmental concerns and waste accumulation from demolition activities in India. The partial replacements of cement with 10%, 15%, and 12.5% fly ash, alongside 10%, 15%, and 12.5% WBP in M25-grade concrete, are investigated over a 7-day curing period. The compressive strength is evaluated as the primary parameter, while specific gravity tests are conducted to analyze material properties. The study aims to assess the sustainability and cost-effectiveness of incorporating fly ash and WBP in concrete production. The results reveal the influence of varying fly ash and WBP proportions on concrete strength, with the optimized mix of 12.5% fly ash and 12.5% waste brick powder demonstrating superior strength properties compared to conventional concrete. This blend demonstrates practical feasibility and potential for widespread adoption in construction applications. This study underscores the sustainable utilization of industrial by-products, aligning with eco-conscious construction practices and contributing to reduced carbon emissions. This paper provides insights for the construction industry in India, offering a solution to waste management challenges while enhancing the sustainability and cost-effectiveness of concrete production. [ABSTRACT FROM AUTHOR]

The mitigation of sewage sludge is quite challenging, as the general method of disposal of sludge after being treated at the waste water treatment plant is landfilling, which makes land unfit for either agricultural or commercial growth. The disposal of sewage sludge in India presents significant environmental challenges due to increasing urbanization and limited land availability. Understanding the potential use of sewage sludge as a construction material has been verified to be the best method of recycling and environmental protection. The possible use of sewage sludge in civil engineering firms is discussed in this paper, along with the various testing methods. Carefully treated sewage sludge is proven to be an effective material, either as a replacement for cement or aggregates in construction. This paper indicates that sewage sludge can be effectively utilized as a raw material in concrete, contributing to resource conservation and environmental sustainability. It supports the feasibility of using sewage sludge in various construction applications, such as eco-cement, bricks, and lightweight aggregates, offering an eco-friendly solution to sewage sludge disposal. [ABSTRACT FROM AUTHOR]

Landfilling is the most common and cheapest method of waste management practice in India. Municipal Solid Waste Landfills (MSWL) became a nuisance affecting the health, hygiene, sanitation and aesthetics of the surrounding area. Aggregates occupy almost 70% of concrete, so replacing waste materials with them could be a rewarding choice. In the current work, an experimental investigation is being carried out to test the addition of MSWL as a substitution with fine aggregate for concrete production. Out of the different aged samples available at the dumpsite, the most aged sample is chosen for experimental investigations according to the basic physical properties. Concrete mixes, with 0%, 4%, 5%, 7% and 10% partial replacement of fine aggregate with MSWL are tested for mechanical properties such as compressive strength, split tensile strength, flexural strength, and nondestructive test and have proved to be a partial substitute for fine aggregate. Durability studies such as water absorption, acid attack and sulphate attack also gave better experimental proof for the sustainable reuse of this waste material. The research reveals 5% replacement is the optimum considering all the test result values. The paper leads to advanced research for the suitability of the material in the construction industry. [ABSTRACT FROM AUTHOR]

Assessing the probability of failure of typically adopted cover depths to resist the onset of carbonation-induced corrosion under the influence of seasonal rains is important for the durability design of reinforced concrete elements. The exposure scenario commonly manifests in the tropics, wherein the majority of monsoonal rainfall remains confined to location-specific annual wet-spells. The study aimed to develop an improved methodology for the identification of annual wet-spell and proposed an index based on the judicious combination of wet-spell characteristics to enable the mapping of its severity over a region of interest and facilitate the selection of Moisture Reference Years (MRYs). The developed paradigm was implemented using gridded meteorological data sets to map the severity of annual wet-spell at 1° resolution for India. The map provides an improved severity classification compared to rainfall amount over regions of scanty rain but considerable wet-spell duration. The estimates of time conducive for carbonation over a period of 100 successive MRYs, as deduced from the simulated moisture distribution data for the five climatic zones of India, were also found to correlate well with the corresponding index values. Finally, the √t modeling of the carbonation depth using the derived estimates of conducive duration and assessment of failure probabilities of typical cover depths suggested that a nominal depth of 45 mm is able to resist carbonation at a safety level of 90% for all the five climatic zones. [ABSTRACT FROM AUTHOR]

Sustainable development goal 6: clean water and sanitation—could be a big challenge for water-stressed India. Use of non-potable water for concrete production can contribute largely towards this goal. Scattered experimental studies on concrete mixed with non-potable water having different pH, were collated to prepare a pan-Indian database. Using this data, probability of code compliance of Indian concrete for varying ranges of pH value of mixing water, within the limits permitted by the Indian code (6–8.5), were estimated for the first time in India. A bootstrap-based re-sampling approach was employed for this purpose. The results indicated that fulfilling the 28-day strength requirements would possibly concurrently fulfill similar stipulations for 7-day strength for Indian concrete mixed with non-potable water of varying pH. However, the probabilities of meeting the Indian code requirements were between 54%-66% for pH ranges starting from 6; and between 66%-85% for others (95% confidence). Considering the entire range of pH (6–8.5), this probability was 66% for 28-day and 72% for 7-day (95% confidence). Probabilistic approach for examining the strength/setting time compliance, along with inclusion of 7-day strength as well as durability aspects in future experiments would help to promote use of non-potable sources of water and reduce use of freshwater for mixing concrete in India. [ABSTRACT FROM AUTHOR]

The significant growth of steel production in India has led to a considerable increase in the production of granulated blast furnace slag (GBS). To resolve the environmental concerns associated with GBS production, it can be used as a substitute for natural fine aggregate in concrete within concrete-filled steel tube (CFST). However, literatures regarding the behaviour of GBS aggregate added concrete-filled steel tubular columns (GBSCFST) after exposure to fire is very limited. Hence the present research work aims to investigate fill the aforementioned research gap. A total 30 number of GBSCFST specimens having square, circular and rectangular shapes, including both intermediate and stub columns, are tested. GBS is used as fine aggregate for preparing infill concrete. All the specimens are heated to varying target temperatures of 200°C, 400°C, 600°C and 800°C with a temperature holding time of 2 h in a furnace. Afterwards, the specimens were left inside the furnace for cooling purposes. Axial compression load was applied to all the specimens by using a compression testing machine with a strain-controlled procedure. The reduction in the load carrying capacity ranged from 1.07% to 12.68% for stub specimens and 1.05% to 19.35% for intermediate specimens heated upto 600°C. However, the load carrying capacity experienced a significant reduction reaching a maximum percentage decrease of 24% and 34% when heated at 800°C. The primary failure shapes observed were local buckling and bulging in stub specimens and mid-height buckling in intermediate specimens. [ABSTRACT FROM AUTHOR]

In general, all countries in the world use ordinary Portland cement concrete for the construction purpose; this ordinary Portland cement (OPC) gives good mechanical properties and durability to the buildings. The binder cement and the filler aggregate are the ingredients widely used in the process of concrete. Natural resources are used to extract both filler and binder elements. In India, the fast-growing sectors like infrastructure, smart cities development, and real estate consume concrete in large quantity. Also, India is the second largest cement manufacturer in the world. The need of cement is increasing day to day, even though the country is manufacturing the cement more than the required demand. In an average, the cement manufacturing industries produce 6% of CO2; for example, if industries produce 1 tonne of cement, they also emit 1 tonne of CO2. This brings us environment changes and produces more pollution to the country. To handle this situation, after many research, geopolymer concrete has been developed. Geopolymer concrete (GC) is all about mixing of source materials to the alkaline solution. Fly ash (FA) that is collected from the power plant is used in GC. The FA-based GC gives more strength when compared to the normal OPC concrete. Under ambient and steam curing, the compression, flexural strength, and tensile strength of FAGC and steel-reinforced geopolymer (SFGC) were tested and results were compared with normal concrete. FAGC mix proportions were studied under different ratios for sodium hydroxide and sodium silicate with 10 M. When compared with normal cement, the strength given by FAGC achieved good strength under ambient temperature. FAGC was further tested for the acid, sulfate, water absorption, and sorptivity test and compared with OPC concrete. [ABSTRACT FROM AUTHOR]

The objective of this bibliometric review is to deliver an in-depth examination of the dynamic field of geopolymer concrete, revealing its evolution, current trends, and possible future trajectories. The method involves a rigorous bibliometric analysis of research output since the field's inception in 2003, underlining key milestones and mapping research patterns. Findings show a consistent surge in geopolymer concrete research, exemplified by over 1360 annual publications, with notable contributions predominantly from Australia and India. The paper also uncovers the increasing practical applications of geopolymer concrete, especially in construction processes, underpinned by a wealth of research on fly ash, a crucial manufacturing component. Additionally, prevalent research themes include compressive strength, fly ash, and geopolymer itself. The review's novelty lies in its comprehensive overview of geopolymer concrete research, elucidating past and present trends and identifying potential future research areas. It thereby serves as a firm foundation for further studies, fostering continued growth in this promising field. [ABSTRACT FROM AUTHOR]

Day by day plastic use is increasing thereby produces waste. Scholars are working to calculate cement characteristics for mixtures comprising several different unwanted plastic material as combined, grout or fibrous material for concrete makings. Almost all desirable properties for paver block making are discussed in this paper for the noble cause. Critical review is done to reduce use of concrete material with plastic waste in paver block so as to produce it economically and utilize plastic waste in paver blocks. Currently in India 56 lakhs ton of waste plastic is created annually. Since deprivation rate of waste plastic is a sluggish process. Lot of work is done by scholars in this direction for use of unwanted plastic in convenient manner. Plastic waste could be treated in diverse quantities of excavation dirt, grainy amassed and unwanted ironstone. It is observed that paver block could be effectively used, prepared with waste plastic materials has vast application in low load of floor space regions. [ABSTRACT FROM AUTHOR]

An enormous amount of industrial waste is generated annually by India's manufacturing sector, and unless resources are efficiently conserved and managed, this problem will continue to worsen. This waste contains nearly a million tons of ceramic debris. India accounts for over 6% of global manufacturing, and currently ranks third in terms of consumption. Similarly, a significant amount of waste is generated after tile utilization, and its disposal poses a challenge. With extensive construction and infrastructure development, natural sand is rapidly being depleted from water sources. This research proposes a suitable replacement for fine aggregates by effectively utilizing ceramic waste powder in concrete, which can address the issues of fine aggregate replenishment and the disposal of broken ceramic tiles. [ABSTRACT FROM AUTHOR]

Evaluation and optimization of multi-criteria with multiple alternatives have been essential activities for decision-making process. TOPSIS (Technique for order of preference by similarity to ideal solution), a multi-criteria decision-making (MCDM) technique, has been adopted in the past for research & decision-making and ranking of alternatives by optimizing input parameters to get the maximum overall output from the system. This study aims to explore the context, reasons, and particular advantages of using TOPSIS in the materials science and engineering field for realizing goals of competitive supply chains (SCs). This study has reviewed and analyzed research papers from the approach of systematic review of the literature. This study has presented a conceptual framework to emphasize the antecedents and consequences of using the TOPSIS methodology for output optimization in the materials science and engineering industry that can improve the competitiveness of SCs. This study found that TOPSIS based methodologies have been used in eleven types of industries in India, indicating the prowess of TOPSIS methodology. The results of TOPSIS have compared very well with other MCDM methods that are relatively more difficult and cumbersome. This study will help the engineers, practitioners, academicians, researchers, and SC managers with the application approach of TOPSIS for output optimization in various fields. [ABSTRACT FROM AUTHOR]

Fe-600 grade steels are recommended for high rises and other structures in India that require high-load carrying capacity (particularly in seismic zones) due to its excellent mechanical properties. But structures in food processing, agricultural waste handling, etc., industries and high rises are subjected to attack of sulphates as well as acid rain. The present work investigates the efficacy of electroless nickel coatings in corrosion prevention of Fe-600 grade rebars exposed to aggressive sulphate environment. Ni-P, Ni-P-W and Ni-P-Cu coatings were deposited on the rebars. Electrochemical tests such as potentiodynamic polarization and electrochemical impedance spectroscopy were employed to investigate the corrosion behaviour in 0.5 M sulphuric acid. It was seen that corrosion potential of rebars was nobler when they were coated with electroless nickel ternary variant coatings. Electrochemical impedance spectra also validated the same. Scanning electron microscope images of the surface of the bare rebars post electrochemical tests revealed a completely cracked morphology due to severe attack of sulphates. Whereas the surface of Ni-P-W coated rebar revealed the least damage and highest corrosion resistance. [ABSTRACT FROM AUTHOR]

Self-compacting concrete can encompass even the most crowded support using nothing more than its own weight and without vibrating. It is a highly flowable, non-isolating solid. It can also fill formwork. While keeping or enhancing all of concretes traditional mechanical and strength capabilities, it offers these alluring advantages. Thanks to adjustments in compliance with traditional blend designs and the usage of superplasticizers, this strong may also fulfill move execution requirements. Self-compacting concrete has a floor this is especially higher than regular concrete, making it suitable for utilization in formwork this is problematic and can be hard to solid in sure ways, in significantly bolstered areas, or in conditions in which vibrators aren't to be had for compaction. Self-compacting concrete, on occasion called self-solidifying concrete, may also waft via the formwork and integrate below its personal weight whilst being definitely deaerated. It can persist lengthy sufficient to fill areas of virtually any length or form with out setting apart or going extinct. As a result, SCC is in particular useful in situations in which placement is hard, together with in strong folks who are well-armed or in complicated paintings environments. This research focuses on the feasibility of employing self-compacting concrete in M30 grade self-compacting concrete (SCC) with superplasticizer and viscosity modifying agent additions. In laboratory studies, the fresh and hardened characteristics, as well as the durability of SCC (M30), are investigated. The prospect of using robo sand, which is one of the most common agro-wastes in South India, as a partial substitute for fine aggregate in specific concretes like SCC in structural components is investigated and explored. [ABSTRACT FROM AUTHOR]

Mining and extraction of stones and minerals play a significant role in many countries economic growth in the world. The production of dolomite minerals in various industries in India and other countries produces vast amounts of waste in different fractions. Disposal of these types of industrial wastes in an immense quantity causes environmental pollution. The performance of dolomite mining residues on concrete properties as a fine aggregate substitute was examined. The microstructural analysis was conducted on the concrete samples to find the effect of dolomite mining residues in concrete. The stress–strain behaviour of the dolomite mining residues concrete was studied. The effect of exposure to elevated temperature and freeze–thaw on concrete properties containing dolomite mining residues was found up to 100% at 10% incremental order. The thermogravimetric analysis (TGA) and differential thermogravimetry (DTG) tests were conducted on the dolomite mining residues and concrete samples. As a test result, concrete properties influence with the incorporation of the dolomite mining residues as a substitution of river sand, but no significant effect is observed in the concrete properties containing 10% dolomite mining residues. Up to 10% of dolomite production waste can be used as a sand substitute in concrete and other applications for sustainable development. [ABSTRACT FROM AUTHOR]

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Concrete production is energy-intensive and has an adverse impact on the environment due to the raw materials involved. Currently, India has abundant reserves of fly ash and ground granulated blast furnace slag (GGBS). Despite various applications, fly ash often ends up in landfills. Given its abundance, there is a growing interest in utilising substantial quantities of fly ash in concrete production. In the current study, M30-grade concrete is designed with very high levels of fly ash and GGBS. Additionally, quick lime (QL) is incorporated as a supplementary agent to augment lime content. A total of twenty concrete mixes have been developed with different combinations of fly ash, GGBS, and QL. Results illustrate that the addition of QL does not show overall strength improvement to the GGBS-based mixes, but it impacts on fly ash-based mixes. The targeted design strength is achieved with 70% cement replacement with fly ash and QL. The strength development depends on the pozzolanic reaction initiated and the formation of hydration products in the system. The environmental impact of concrete is assessed by analysing its life cycle assessment using a cradle-to-gate approach. The energy requirement and kg-CO 2 eq. emissions depend on the level of cement replacement. The fly ash-based concrete emits less kg-CO 2 eq. and requires less energy than the GGBS-based mixes. Overall, the designed strength is achieved with 65% fly ash, requiring 59% less energy, reducing 54% CO 2 footprint, 56% GWP 100 , 80% HTP inf , 46% ODP inf, and cost by 34% compared to OPC-based concrete. [Display omitted] • Large quantities of fly ash and GGBS are used in concrete production. • A life cycle assessment and cost analysis performed on concrete samples. • High-volume fly ash concrete is cost-effective, eco-friendly and maintains adequate strength compared to high-volume GGBS concrete. • The proposed approach reduces virgin material extraction and preserves natural resources. [ABSTRACT FROM AUTHOR]

Constructions and demolition activities was increased normally for the past two decades. With these type of construction activities going up, we are having short for these construction materials, mainly aggregates, therefore finding an other type resource is the need of time. Laboratory trials have conducted to investigate the possibility of using recycled aggregates as the replacement of natural coarse aggregates in the concrete. Large quantities of construction and demolition wastes were happened every year in developing countries like India. The disposal of this waste is a very big problem, because it needs large space for its disposal and that too very little demolished waste is recycled. This study is a part of comprehensive program where in the experimental investigations have been carried out to assess the effect of partial replacement of the coarse aggregates by the demolished waste on workability and the compressive strength of the recycled concrete for study at 7,14& 28 days. In this study replacement of recycled aggregate was done in four proportions i.e. 0%,10%,20%&30%. Each sample was tested for compressive strength for 7, 14 & 28 days and compared with standard concrete. [ABSTRACT FROM AUTHOR]

The carbon dioxide produced by cement industries causes environmental pollution and global warming. In 1000 Kg of cement manufacturing processes, approximately 900 Kg of CO2 is emitted. In order to reduce the impact of cement production on atmosphere, waste bi-products are used as admixture. In India, every year 75 million tons of fly ash, which are rich in silica, are disposed to landfill as waste. Also, Egg Shell Powders (ESP), which are rich in calcium, are thrown away as waste. In the paper, these two wastes are used as a partial replacement of cement, and various properties like workability, compressive strength, split tensile strength and flexural strength are studied. ESP was varied up to 15.0% (0%, 2.5%, 5%, 7.5%, 10%, 12.5% and 15%) and fly ash was added to cement from 0% to 30% (0%, 5%, 10%, 15%, 20%, 25% and 30%). The results further showed that addition of fly ash along with ESP is beneficial for improved performance of concretes. [ABSTRACT FROM AUTHOR]

Production of ordinary Portland cement is consuming enormous energy and releases high carbon dioxide. Additionally, the use of river sand as fine aggregate has a direct effect on the erosion of river banks due to excess sand mining and hence, the use of river sand in concrete is banned in many developing countries. Hence, the assessment of concrete with blended cement and locally available alternative fine aggregates is the need for current construction practices. India becomes the ‐largest sugar producing country, a massive volume of bagasse ash (44,200 t/day) is discarded as waste. Similarly, marble processing plants dispose of marble slurry dust. An exploration of the use of agricultural and mining wastes in crusher sand‐based concrete is not yet reported. The current investigation focuses on the potential use of bagasse ash and marble slurry dust as pozzolan and alternative to crusher sand respectively in concrete and interlocking paver blocks. Compressive strength and capability against abrasion were investigated for bagasse ash and marble slurry dust blended concrete and paver block. Besides, water‐based tests were adopted to examine durability performance. Results from the study indicate an enhancement in abrasion resistance and a substantial reduction in permeability for blended concrete than control concrete. Optimum replacement levels were found to be 20% for bagasse ash and 25% for marble mining powder. [ABSTRACT FROM AUTHOR]

The quality of the construction material is required to be improved to enhance the strength and performance of the structure. From the earlier days, admixture assumes a crucial job in cement to improve the basic properties. Before knowing about the admixtures, good knowledge regarding concrete is required. In this work, an endeavor was made to contemplate the conceivable outcomes of utilizing tamarind kernel powder, a naturally available biowaste material which is a hydrocolloid in nature, as an admixture in concrete. The addition of tamarind kernel powder was varied from 0.25 to 1.25% in proportion to the weight of cement used. A huge amount of tamarind seed wastes are produced every year especially in India it is nearly 97,000 metric tons per year. In the absence of waste disposal, the utilization of tamarind seed for concrete improvement will be a great development. In this research article, tamarind kernel powder was added to fresh concrete and relevant tests were conducted on fresh and hardened concrete before and after the addition of tamarind kernel powder. Further, nondestructive tests were also carried out on concrete added with tamarind kernel powder. The concrete shows good enhancement in strength until the addition of 1% of tamarind kernel powder to the weight of cement. Moreover, the workability, mobility and compaction factor results obtained in this experiment show that the optimal addition of tamarind kernel powder does not affect the properties of fresh concrete. The tests on hardened concrete and results obtained from nondestructive testing methods confirm the same. Hence, this experimental work shows that the natural hydrocolloid, that is, tamarind kernel powder can be added to an amount of 1% to the weight of cement which shall not affect the other parameters of concrete but increases the strength considerably. [ABSTRACT FROM AUTHOR]

This study was undertaken to evaluate the potential of demolished building waste (DBW) as aggregates in alkali-activated concrete (AAC). A recent road-widening activity led to the demolition of commercial buildings along National Highway 275, Bangalore-Bantwal, India. DBW was collected from these sites and processed manually at the laboratory facility of CHRIST (Deemed to be University). Processing of DBW was done to obtain both waste coarse and fine aggregates from demolished concrete and brick waste units, respectively. AAC was synthesized by fly ash, ground granulated blast furnace slag, sodium hydroxide, sodium silicate, along with waste aggregate replacement rates of 0, 25, 50, and 75% by weight of natural aggregates. Fresh and hardened properties of developed concrete mixtures were experimentally determined. Results of the study indicate that 28-day compressive strength of 30.4 and 21 MPa was obtained for AAC with 25 and 50% DBW aggregates, which was 8.6 and 36.9% lower than control mix, respectively. Further, there was an increase in the water absorption and a reduction to acid resistance for all the AAC mixes with DBW aggregates. Based on the results obtained, it was observed that AAC with 25 and 50% DBW aggregates find great potential in civil engineering applications. [ABSTRACT FROM AUTHOR]

The extraction of marble and its processing as marble blocks is most common in several states of India. But the extensive growth of this industry has put adverse impact on the environment because of the production of huge amount of marble waste during extraction and processing. This experimental study highlights the impact of use of marble waste on the properties of lean concrete mix designed for the production of bricks. The basic objective of this experimental programme is to replace river sand in concrete by an optimum combination of quarry dust and marble waste in order to extract best performance in terms of strength and durability parameters. By varying the percentage replacement of fine aggregate with marble waste (0–100%), six concrete mix proportions were prepared for experimental purpose. The result shows that all these properties improved for complete substitution of fine aggregate with marble waste. It was found that compressive strength and flexural strength increased by 84% and 18.6%, respectively. The mixes were less reactive to the aggressive agents also. These advantages were derived due to the ability of marble fines impart necessary cohesiveness even at lesser water content which resulted in an impermeable microstructure. [ABSTRACT FROM AUTHOR]

The study on the characteristics of geopolymer concrete (GPC) is of ultimate significance to instill assurance in builders and engineers. Abundant available literatures point towards the utilization of fly ash and ground granulated blast furnace slag (GGBFS) as source material in the production of GPC with little on other materials. India produces nearly 350 MMT of sugarcane for the production of sugar, which lies second only to Brazil in the annual production, the disposal of the bagasse creates an environmental issue needs to be effectively utilized. Hence, this work was intended to investigate the effect of utilizing sugarcane bagasse ash (SCBA) as a source material in the production of geopolymer mixes. The fresh (consistency, setting time, soundness and flow), hardened (density, compressive strength, expansion and pH) and microstructural properties (X-ray diffraction) of the tested mixes were asessed. The results infer that 20 % replacement level of GGBFS with SCBA produces superior compressive strength and all other results were within the permissible limits even at 40 % replacement level. [ABSTRACT FROM AUTHOR]

Policy makers in India have realized the importance of facility for pedestrians and non- motorized vehicles in an urban infrastructure setup. This has resulted in increased utilization of construction materials like Portland cement and crushed stone, which are not environmentally friendly and sustainable. The current study presents the development of paver blocks for pedestrian facility using different wastes. Geopolymer concrete was synthesized by fly ash and recycled asphalt pavement aggregates for making of paver blocks. Paver blocks were produced in laboratory with recycled asphalt pavement aggregate replacement levels of 0%, 20%, 40%, 60% and 80% by weight of virgin coarse and fine aggregates. The developed paver blocks were tested for dimensions and tolerances, water absorption, compressive strength and abrasion resistance as per IS15658:2006 standard. The results of the laboratory study show that recycled asphalt pavement aggregates can be introduced into geopolymer matrix to produce paver blocks of desirable quality. Furthermore, its use in pedestrian facilities provides a new avenue for managing the excessive waste, which otherwise goes in landfills, incurring loss to the paving industry. Therefore, the proposed method can help decision makers to effectively utilize recycled asphalt pavement in paving industry with environment-friendly approach. [ABSTRACT FROM AUTHOR]

The article focuses on design in the context of the unsustainability of certain philosophical and economic concepts on which modern industrialized civilization is built. It addresses both problems of the excessive fragmentation of design as a discipline and its problematic "servitude" to the dominant economic structures of the globalized world. It follows the notion of "invisibility" in design to point to the insufficient reflection of its infrastructural connections, implications that often lead to unsustainable practices. The article argues that in order to better understand the significance and consequences of design, it needs to be understood in a broader context of material production or infrastructural planning. Therefore, it explores the issue of concrete as the ubiquitous material shaping the modern urban environment and water infrastructures that rely on vast amount of concrete to build the supporting construction. As a counterpart to the massive structures, such as sophisticated dams and irrigation systems, it proposes an example of the retrofitting of the existing traditional water infrastructure in Eastern India. The article calls for a complex approach to design that takes into account social, ecological and political circumstances, that is adaptable and resilient, and puts forward several theoretical concepts of design for sustainability reaching beyond the current political and economic status quo. [ABSTRACT FROM AUTHOR]

• Sheltered natural carbonation can be similar between different climates. • Huge impact of curing on natural carbonation for very early age (i.e. 1 day) • Impact of curing is negligible for advanced curing age, regardless of cement type. • Strong impact of precipitation on natural carbonation. • The higher the number of rainy days, the lower the carbonation speed. This paper describes a unique international inter-laboratory study on the carbonation resistance of concrete prepared with different supplementary cementing materials. Concrete specimens – from 45 different concrete mixtures – prepared centrally in Lafarge Centre de Recherche (France) were shipped in a sealed condition to 4 other academia research laboratories (located in USA, Canada, India and China). The specimens were exposed to the ambient environments and atmospheric CO2 concentrations in the five locations, including Lafarge Centre de Recherche in France, in both sheltered and unsheltered condition for a period of 5 years. Measurements of carbonation depth were performed at periodic intervals, and the data was analyzed to assess the influence of climatic conditions on the resistance to carbonation. The results indicate that the general trend of carbonation is not much different irrespective of the macroclimate. Further, the number of rainy days seems to have a more significant influence on the progress of carbonation than the total rainfall in the region. [ABSTRACT FROM AUTHOR]

The knowledge about the utility of fly ash is well known worldwide. Moreover, even though fly ash is widely and abundantly available in India, its optimal utilization is not yet achieved. This paper attempts to give clarity on the viable limit of fly ash in structural concrete. The study confirms the applicability of efficiency factor method in the mix design and strength prediction of concrete. Maximum usable fly ash percentage depends upon the strength of concrete and type of chemical admixture. Although the results presented herein may vary with change of constituent materials, type of concrete, type and power of concrete mixer, ... etc., the trend in results would remain similar and will be useful for both researchers and practicing engineers in concrete technology domain striving for sustainable construction. [ABSTRACT FROM AUTHOR]

Safe disposal of fly ash generated by coal-based thermal power plants continues to pose significant challenges around the world and in India in particular. Green structural concrete with 80% cement replaced by local Chinese fly ash has been recently developed to achieve a target characteristic compressive strength of 45 MPa. Such green concrete mixes are not only cheaper in cost, but also embody lower energy and carbon footprint, compared with conventional mixes. This study aims to adopt such materials using no less than 80% fly ash as binder in routine concrete works in countries like India with the commonly used lower target characteristic compressive strength of 30 MPa. It is achieved by the simple and practical method of adjusting the water/binder ratio and/or superplasticiser dosage. The proposed green concrete shows encouraging mechanical properties at 7 days and 28 days, as well as much lower material cost and environmental impact compared with commercial Grade 30 concrete. This technology can play an important role in meeting the huge infrastructure demands in India in a sustainable manner. [ABSTRACT FROM AUTHOR]

• Indian finely grounded waste glass powders (GP) recycling in M30 and M40 grade concretes. • GP as cement replacement from 0 to 40%, steps of 10% • Workability, compressive strength and durability indicators improved with the increased of GP content. • Increased drying shrinkage with GP content, still within standard limits. • 30% GP as cement replacement provides optimal engineering properties for conventional concretes and paver concrete blocks. Waste glass is a significant concern in India, and management solutions seek. Finely ground waste glass (GP) presents pozzolanic properties, which make it potential for concrete applications as cement replacement. The main feature of the present work lies in the simultaneous incorporation of two GPs with different fineness, generated from consumer scrap in India, as cement replacement in equal proportions, from 0 to 40 %, in two concrete grades, M30 and M40. An experimental programme was carried out, including fresh, shrinkage, mechanical and durability properties. GP concrete specimens showed compressive strength and a slight improvement for both concrete grades compared to reference concrete specimens (0 % GP incorporation). The durability indicators, namely, water absorption, sorption, chloride-ion penetration and moisture movement in GP concrete, improved with the increase of GP content. The drying shrinkage increased with the rise in GP content; however, the results still fit the permissible standard limits. Optimal concrete mixtures were selected to further study GP incorporation in concrete paver blocks. Four concrete paver block types were produced, including M30 and M40 with no GP (0 %GP) and M30 and M40 with 30 % GP as cement replacement (15 % GP1 + 15 % GP2). The compressive strength of the concrete paver blocks with GP significantly improved. Thus, the concrete with 30 % partial cement replacement by GP is a potential option for the construction industry while providing a management waste solution and contributing to a circular economy. [ABSTRACT FROM AUTHOR]

A large number of wastes and naturally occurring resources have been recognized as Supplementary cementitious materials (SCM) for their role in clinker substitution and the resulting low carbon cement. While helpful for optimum utilization, existing literature fails to help stakeholders in selecting a suitable SCM. To address this challenge, the manuscript reviews over 20 different SCMs investigated in India for their availability, characteristics (physical, chemical, mineral and morphological), effect on the properties of concrete (workability, strength and durability) and environmental impact. The study shows that over 380 Mtpa of SCMs are generated in India, more than the estimated need of 105 Mtpa. The asymmetrical distribution of SCM availability call for alternative SCMs in some regions (12.22 Mtpa shortage) and high-volume utilization in other regions (131.88 Mtpa excess). The review uses a characteristics-based classification to identify SCMs with similar traits and understand their effects on concrete. Results show that SCMs having particle sizes similar to cement and spherical morphology improve the workability of concrete. Similarly, SCMs with very-fine particle size (specific surface area greater than 1200 m2/kg) and high Ca content (more than 10% Ca in chemical composition) improve concrete's compressive, flexural, and split tensile strength. The addition of SCM also improves durability against chloride ion penetration and wetting and drying cycles. Recommendations have also been made to guide stakeholders towards the suitable application of different SCMs. Multi-blended cement and long-term environmental impact have also been discussed to help stakeholders select a sustainable SCM. [Display omitted] • Review of over 20 SCMs, their availability, characteristics and effect on concrete. • SCMs grouped by physical, chemical, mineral and morphological characteristics. • Characteristic groups have similar effect on concrete, than similar origin source. • Characterization based approach for identifying suitable application of SCM. • Local waste utilization and multi blend cement for improved sustainability. [ABSTRACT FROM AUTHOR]

Steel slag, a by-product of steel making, is produced during the separation of the molten steel from impurities in steel-making furnaces. The slag occurs as a molten liquid melt and is a complex solution of silicates and oxides that solidifies upon cooling. It is estimated that 115-180Mt of steel slag is poured out annually worldwide and in addition to this previous accumulation of the material has created mountains of steel slag. In India, steel slag output is approximately 20% by mass, of the crude steel output. The slag in India is used mainly in the cement manufacture and in other unorganized work, such as landfills and railway ballast. In order to reduce the pollution load on landfill for the disposal of steel slag at steel industries, it can be effectively utilized in construction as aggregates in concrete. Use of waste materials can solve problems of lack of aggregate in various construction sites and reduce environmental problems related to aggregate mining and waste disposal. The use of waste aggregates can also reduce the cost of the concrete production. In this research work an attempt is made to utilize the steel slag as partial replacement material for natural aggregates in concrete. 10% to 100% replacement was done in 10% increment and fresh and hardened concrete properties were studied. [ABSTRACT FROM AUTHOR]

Coal fired thermal plants in India produce about 131 million tons of coal ash, which comprises about 25 million tons of coal bottom ash. Utilization of coal bottom ash has environmental advantages also which are of great importance in the present context of sustainability of natural resources. The replacement of river sand with industrial by-products such as coal bottom ash in concrete can prove both technically and economically beneficial to the construction industry. In this study, laboratory tests were conducted to assess the possibility of the use of coal bottom ash as a substitute material of river sand in concrete. River sand was substituted with coal bottom ash by mass in concrete at 0, 30, 50, 75 and 100% replacement level. The test results show that 28 d compressive strength and pulse velocity through concrete were not affected on the use of coal bottom ash in concrete. Water absorption and initial rate of absorption of water by capillary action increased on incorporation of coal bottom ash in concrete manufacturing. However, the secondary rate of absorption of water was constant for all concrete mixtures. Water absorption varied between 4.68 and 5.56% for all concrete mixtures at curing period of 28 d. With increasing age, bottom ash concrete mixtures showed significant reduction in permeable pore space and water absorption. Abrasion resistance was measured in terms of average depth of wear. Bottom ash concrete mixtures displayed marginally lesser resistance to abrasion than control concrete. All the concrete mixtures showed decrease in the average depth of wear with increasing age, in other words increase in resistance to abrasion. [ABSTRACT FROM AUTHOR]