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Cement clay interlocking (CCI) hollow bricks have been used as a construction material in many developed and developing countries. Many emerging and underdeveloped nations have utilised cement clay interlocking (CCI) hollow bricks as building materials. In India, Andhra Pradesh local makers prepare these cement clay interlocking (CCI) hollow bricks by simply mixing clay, cement, and sand in a traditional method, without following strict design criteria or rules. Previous research has demonstrated that the mechanical characteristics of CCI hollow bricks gathered from various locations in detailed manner respect to hand books on Civil Engineering as per Indian Standards. Bricks from one region had compressive strengths that were significantly lower than the other region Indian Community Standards. Various methods were employed in this investigation to enhance the mechanical characteristics of CCI bricks. New mix patterns were created with the use of sand, cement, and fly ash in this research paper. [ABSTRACT FROM AUTHOR]

Because of urbanization, demand for housing is increasing day by day in India. Traditional clay brick leads to resource scarcity and environmental pollution. To overwhelmed this problem, manufacturing of bricks was done using the waste of thermal power plants like Fly Ash along with Sand and Cement (FAS-C Brick) as key ingredients. Fly ash is an Industrial by-product of thermal power plant. An experimental study of mix-design was carried out to increase the quality of the FAS-C brick. This paper attempt to formulate the mix design of fly ash based brick by process planning. Laboratory tests were conducted to determine the compressive strength and water absorption of the bricks. The main objective of the research study was to design the Fly Ash, Sand, Cement (FAS-C) brick and find the compressive strength using different mix design methods as a part of quality improvement process. [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]

AAC was introduced in India in 1970s. However, there were only three factories producing a total of less than 1 million m3/year till 2008. Post 2009, AAC blocks gained popularity due to their numerous advantages, including high strength, excellent insulation properties, fire resistance, sound absorption, and cost advantages over alternate walling materials. The use of AAC blocks has also been promoted by the Indian government's emphasis on sustainable and eco‐friendly building materials. The number of factories increased rapidly to over 150 factories with a cumulative capacity of over 25 million m3/year in 2022 (a growth of 25 times in nearly 15 years). Despite the rapid growth, the share of AAC in walling industry in India is still in the range of 5%–6%. There is still a lot of room for the industry to grow. AAC reinforced products have also been recently re‐introduced in India, though it is still at a very nascent stage and the share of AAC reinforced products in total AAC sales is less than 1%. More than 95% of AAC industry in India uses fly ash as the primary raw material and faced challenges initially to stabilize the design mix, due to variations in raw material characteristics. The rapid growth also resulted in improper implementation of standards and processes, during both production and application. The primary issue on the production side has been lower compressive strength and higher corner chipping. The main challenge on the application side has been improper techniques such as non‐usage of reinforcement beams and fiber meshes, which led to cracks in masonry subsequently. Now, the AAC industry is working together with applicators and researchers to overcome these challenges, in order to consolidate the gains and continue the rapid growth trajectory to become the preferred walling material. [ABSTRACT FROM AUTHOR]

Thermal power plants in India produce a large quantity of fly ash, which is harmful to the environment. Underutilization of fly ash and the scarcity of natural minerals have created the need for an unusual construction strategy to prevent huge waste dumps on valuable land and to preserve fast-depleting resources. A study was conducted to determine the efficacy of lime-stabilized fly ash blended with quarry fines as flexible pavement subbase materials. The laboratory investigations were conducted to determine compaction characteristics, unconfined compressive strength, California bearing ratio (CBR), and durability to obtain the optimal quarry fines, fly ash, and lime (QFL) mix. The durability of QFL mixes was studied using 12 wetting–drying cycles. Using the strength and durability criteria specified by the Indian Road Congress, the optimum mix proportion of 40Q:60F+3L was determined. Pavement analyses were performed using the IITPAVE program. The QFL mix was observed to be superior to conventional granular subbase (GSB) layer material in terms of service life and cost-effectiveness. A field investigation was carried out on trial test sections constructed using the optimum QFL mix and GSB in the subbase layer of pavement. Field dry density and dynamic cone penetrometer (DCP) tests were performed on the compacted subgrade and subbase layers to assess the desired quality assurance in the construction of test sections. The early structural performance assessment of pavement sections using a falling weight deflectometer (FWD) test indicated that QFL could effectively replace conventional GSB. [ABSTRACT FROM AUTHOR]

Construction is a process of developing new ventures and is a never-ending activity. The aggregates are the raw materials, which constitute 70-80% in the concrete mixture. Every year, it is estimated that the construction industry in India generates about 10-12 million tonnes of waste annually. Concrete is the most versatile material which is used extensively in the construction field. There is a need to think of alternate materials because of the scarcity of natural aggregates. The use of this recycled coarse aggregate is mainly for two reasons: To decrease CO2 emission which is harmful to environment and to reduce the cost of construction material / cost cutting/reduce the budget of the construction. C&D waste can be reduced, re-used and recovered, dramatically reducing the dumping of demolished waste. The main purpose of recycling is to minimize the amount of waste to be deposited and to preserve natural resources. The present investigation is carried out for evaluation of properties of natural and recycled aggregate concrete. Pozzolanic materials like Fly Ash and Silica Fume are used as mineral admixtures for good workability and for better strength. Cement is replaced with 10% SF and 20% FA in design mix. RAC20 made with different grades of recycled aggregates of GA20, GA25, GA30, GA35 and GA40 with different replacements 50%, 75% and 100%. During mix proportion presoaking of aggregates is done before the mixing of concrete. Three stage mixing approach is adopted for the production of concrete. The density of concrete, compressive strength and water absorption of PC & RAC were determined at ages of 7 and 28 days. The results of compressive strength are found to be lower than target strength. With GA20 at 50% replacement, 95% of the target strength is achieved (27.55MPa). Strength could have achieved with increase in curing period. It is also concluded that the water absorption and density of RAC is lower than NAC. [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]

The study emphasizes on physico-chemical, mineralogical, morphological, and mechanical characteristics of Coal Combustion Residues (CCRs) collected from two different thermal power plants. To determine utilization potential and valorization, specifically in the Indian cement sector more than governing guidelines of Indian Standards (IS), collected CCRs (Fly and Bottom Ash) samples were analyzed for physical, chemical, and mechanical characteristics. The characterization included pH, moisture content, acid insoluble residue, chlorides, reactive silica, LOI, carbon, Blaine fineness, XRF, SEM, XRD, FTIR, initial and final setting time, consistency and soundness, lime reactivity, and compressive strength at 7, 28, and 90 days. The characteristics were analyzed and selected with a view to determine their suitability as mineral additives in the cement sector. The study showed that; collected CCR samples fulfill the requirements of the Indian standard (IS:3812) as well as ASTM C-618 for physico-chemical and mechanical characteristics and show potential for increased use in the cement industry as mineral additives. The study also highlights that; up to 30% CCRs can be used as a mineral additives during cement manufacturing, and if long-term strength is considered up to 50% replacement can be possible. [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 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]

Mine overburden removed during surface mining is considered as “waste” or “spoil” that is consuming a vast tract of land for storage. Due to high ash content (30–50%) of Indian coals, 130 million tons of fly ash per year is generated with less than 50% of it is being used. Many a time thermal power plants are close to coal mines. Hence, in the present study it is proposed that a mixture can be prepared using fly ash and coal mine overburden with or without cement, which can be used as a stabilized pavement material. The present study deals with characterization of cement stabilized mine overburden fly ash mixture as a pavement material. Mixtures with varying cement percentage of 4–7% were prepared. Based on the unconfined compressive strength and California Bearing ratio values of the stabilized mixture, it was observed that it can be used as a stabilized pavement material. [ABSTRACT FROM AUTHOR]

Utilization of reclaimed asphalt pavement (RAP) in the construction industry is gaining an advantage over conventional materials in terms of sustainable credits. However, the amount of production of RAP and its utilization has no comparison. The general practice is to replace a small fraction of virgin aggregates with RAP, usually restricted to a maximum of 30%, in base layers to promote RAP usage in the pavement industry. The present study focuses on the utilization of a high proportion of RAP (>50%) substitution in virgin aggregates (VA) as a base material in low volume roads (LVR). Mixes containing 100:0, 80:20, and 60:40 proportions of RAP:VA stabilized with different dosages of fly ash were evaluated for maximum dry density (MDD), optimum moisture content (OMC), unconfined compressive strength (UCS), resilient modulus (Mr) and California bearing ratio (CBR). It was observed that the 80:20 RAP:VA design mix with 40% fly ash meets the design requirements (UCS > 1.7 MPa and CBR > 80%) specified by the Ministry of Rural Development (MoRD), Government of India, and was considered to be an optimum mix. An example is discussed to design an LVR with an optimum mix according to the Indian Roads Congress (IRC) and AASHTO methods. The results revealed that the fatigue and rutting strains are well within the permissible limits for the new mix. The new mix design proved economical, as there was a 50% reduction in base layer thickness compared with the conventional design mix. [ABSTRACT FROM AUTHOR]

The production and utilization of coal is based on well-proven and widely used technologies. Fly ash, a coal combustion byproduct, has potential to produce a composite material with controlled and superior properties. The major challenges with the production of fly ash are in its huge land coverage, adverse impact on environment etc. It puts pressure on the available land particularly in a densely populated country like India. In India the ash utilization percentage has not been very encouraging in spite of many attempts. Stabilization of fly ash is one of the methods to transfer the waste material into a safe construction material. This investigation is a step in that direction. This paper presents the results of an investigation on compressive strength and bearing ratio characteristics of surface coal mine overburden material and fly ash mixes stabilized with lime for coal mine haul road construction. Tests were performed with different percentages of lime (2, 3, 6 and 9%). The effects of lime content and curing period on the bearing ratio and tensile strength characteristics of the stabilized overburden and fly ash mixes are highlighted. Unconfined compressive strength test results cured for 7, 28 and 56 days are presented to develop correlation between different tensile strengths and unconfined compressive strength. Empirical models are developed to estimate bearing ratio and tensile strength of mine overburden-fly ash-quick lime mixtures from unconfined compressive strength test results. [ABSTRACT FROM AUTHOR]

Sewage sludge (SS) management has been regarded as a serious environmental and health issue around the globe, especially in developing countries like India, mainly due to the lack of proper regulatory criteria, and appropriate engineering infrastructures. The present research work demonstrates the utilization of Fly Ash (FA) in varying percentages (with an interval of 10%) with SS as brick for sustainable building material with special emphasis on dimensional Effect. The impact of dimensional effect is measured using compressive strength behaviour for a stress rate of 14 MPa/min of two different sizes of brick i.e. D1 and D2 of sizes 7 × 7x7 cm3 and 2 × 2x2 cm3, respectively. Owing to the sintering effect, the maximum strengths of 4.02 MPa and 7.6 MPa are noticed for a composition of 60% SS+40% FA for D1 and 40% SS + 60% FA for D2, respectively. According to the Indian Standards (IS) 13757: 1993, an exhibited strength of more than 3.5 MPa by any brick composition enables it to be used as a common building brick. In general, due to the formation of triangular wedges, the D2 bricks exhibited better strength for any mixing ratio of FA and SS. The added benefit in our study was lower thermal conductivity (0.48 Wm−1K−1) of the prepared fired brick implying its better insulation property. Our study uniquely highlights the possible utilization of FA for stabilizing SS for sustainable substitution of natural clay fired brick. Future study may further investigate the compositional effect of FA on the thermal and thermodynamic attributes of the bricks. Image 1 • Pioneer study on bricks that visualizes dimensional effect along with mechanical properties. • 40–60% fly ash with sewage sludge satisfies Indian codal provisions as construction material. • Thermal conductivity of synthesized brick is lower than conventional fired clay bricks. • Dimensional effect significantly influences the compressive strength behaviour. [ABSTRACT FROM AUTHOR]