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• The usability of a paper mill sludge compost (PMSC) in the brick making is established. • Up to 10 wt% of PMSC was suitable for bricks production as per relevant standards. • It is proved that the products can be used in non load-bearing and infill walls. • TCLP procedure demonstrated the non-hazardous nature of the obtained bricks. This study's focus was to develop a potential pathway for recycling of the paper mill sludge compost (PMSC) in brick making. Composting reduces the paper mill sludge (PMS) moisture content considerably and shredding becomes easier. The addition of PMSC leads to an increase of porosities in bricks and makes them lighter, besides delivering energy to the firing process from burning organics. Lighter construction materials help minimize construction outlay by reducing labour and transportation costs and lesser expense on foundation construction. The variability in the experimental data and the brick properties were investigated for two types of soils, typical in the brick industry of India (alluvial and laterite soil), blended with PMSC in five mix ratios (0%, 5%, 10%, 15% and 20%). The samples of oven-dried bricks were fired at two different temperatures (850 and 900 °C) in an electrically operated muffle furnace representing typical conditions of a brick kiln. Various properties of bricks were analyzed which included linear shrinkage, bulk density, water absorption and compressive strength. Conclusions were drawn based on these properties. It was found that the addition of PMSC to the alluvial and laterite soil by up to 10% weight yield mechanical properties of fired bricks compliant with the relevant Indian and ASTM codes. Toxicity characteristic leaching procedure (TCLP) tests showed that PMSC incorporated fired bricks are safe to use in regular applications as non-load-bearing and infill walls. This study is timely in light of the European Green Deal putting focus on circular economy. Besides, it fulfills the objective of UN sustainable development goals (SDG). [ABSTRACT FROM AUTHOR]

• Permeability and pore structure of the porous concrete mix was checked with over burnt brick aggregate. • A nonlinear relationship was obtained between permeability and porosity of porous mix. • Minimum permeability for single sized and dense graded aggregate was found to be 0.5 cm/s and 1.4 cm/s, respectively. • An increase in aggregate size leads to the increase in permeability. • Kozney-Carman model for permeability is modified for over burnt brick aggregate. The scarcity of regular construction material has always been a challenging concern in some of the North-Eastern states of India like Tripura. To meet this inordinate shortage, brick aggregate has earned an immense attention due to its availability and low cost. The main purpose of this paper is to correlate the pore structure and hydraulic conductivity of the porous concrete matrix using brick aggregate to meet the insufficiency of conventional aggregates. Pervious concrete pavement, due to its eminence as an eco-friendly pavement system, has become an emerging technology in the developed and developing countries. In this paper, a series of pervious concrete mixes are made with over burnt brick aggregate and the porosity and permeability are evaluated. Water-cement ratio, aggregate size and the presence of fine aggregate in the porous mix are chosen as the mix variables and their contributions in controlling the permeability is quantified. A relationship is then drawn between permeability and the pore features considering the relative mean pore size and pore tortuosity. A modified Kozney-Carman model for pervious concrete is also developed using the investigational test results and the predicted equations. The predicted values and the developed relationships provide a very good agreement with experimental test results. [ABSTRACT FROM AUTHOR]

• Characteristics of incised plaster from monuments in Delhi are explored. • Marked differences exist between the incised plaster mortar and typical bedding mortars of the region. • The use of organic fibres and recycled components from an older mortar is seen. This paper reports the characteristics of decorative incised plaster works of New Delhi, from historic monuments belonging to 13th to 16th century C.E. Visual examination of the historic plasterwork depicts that these are made of two layers; a base coat which is coarser in appearance and a finer finishing coat, which is the incised plaster layer. For making the intricate patterns in the incised layer, a thick coat of plaster is applied first and patterns are carved out before the initial set of the mortar, which later hardens to form a very dense microstructure. In order to consolidate and restore the deteriorated portions of the existing plasterwork, the characterisation of the original plasterwork was essential. This was performed by a comprehensive methodology including physico-chemical and microanalytical tests, which revealed information on basic physical properties, mineralogical composition, characteristics of different phases, and porosity and pore size distribution of the mortar. The results indicate that the incised plaster is made of air lime binder and siliceous aggregates. The mortar is characterised by a very narrow range of pore sizes of about 600 nm. The use of organic fibres and inclusions from an older mortar are also evident in the analysis. [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]

• Feasibility of industrial wastes in brick production is reviewed. • Design and development of alkali-activated bricks are studied. • Physico-mechanical and durability properties are reviewed extensively. • The factors responsible for the brick performance are examined. • Alkali activation provides sustainable solutions for brick production. Brick is one of the majorly used building materials for masonry construction. Unlocking the potential to deliver significant impact against India's current housing and agro-industrial waste challenges is crucial. This can be met by developing sustainable products using industrial wastes. Alkali-activated products are claimed to be sustainable and cost effective, giving rise to Portland cement free products. The paper presents a state-of-the-art review on the development of sustainable bricks by alkali-activation of industrial wastes. Physical and chemical characterisation of industrial wastes are discussed in order to check its feasibility for the development of alkali-activated bricks. The influence of parameters on physico-mechanical and durability related properties are evaluated. Previous studies show that bricks with the appropriate values of molarity, alkali modulus, liquid-binder ratio and water glass-NaOH ratio (5–15 M, 0.15–0.9, 0.2–0.48 and 0.5–2.5 respectively) achieves a compressive strength of 5–60 N/mm2. Though considerable research has been carried out, application of industrial wastes in the alkali-activated bricks manufacturing are still limited and some recommendations are suggested. Geopolymeric bricks seems to be the most advantageous as they can incorporate high content of wastes. It signifies the potential use of waste materials to form alkali-activated brick as an alternate sustainable masonry option. [ABSTRACT FROM AUTHOR]

• Pore features of pervious concrete mixes are found through image analysis. • Pervious concrete mixes are prepared with non-conventional over-burnt brick aggregates. • Stereological analysis and mathematical morphology such as two-point correlation and granulometric distribution analysis are employed here. • Weibull distribution is the best way to fit the pore diameters of the pervious concrete mixes. The present study deals with the pore feature analysis of porous concrete mixes based on image analysis technique. The porous concrete mixes are prepared with over-burnt brick aggregate having different sizes and different aggregate gradations. The scarcity of natural aggregates in Tripura, India has forced the researchers to use locally available waste bricks as a coarse aggregate in construction purposes. However, the application of bricks in porous concrete is very rare and the porous distribution of porous mixes made of brick aggregates are not well-known. Hence, in this paper, initiatives are made to characterize the porous features of pervious concrete mixes using bricks as coarse aggregates. Stereological analysis and mathematical morphology such as two-point correlation and granulometric distribution analysis are employed in this paper. Statistical analysis is also conducted to identify the distribution of the pores and is observed that the 3-parameter Weibull distribution is the best way to fit the pore diameters of the pervious concrete mixes. Finally, the relative mean pore size is identified and the permeability of the pervious mix is obtained based on this image analysis. From the overall analysis, it is found that the image analysis can be an efficient way to identify the pore features of the porous concrete mixes. [ABSTRACT FROM AUTHOR]

This paper study the occurrence of aragonite–vaterite–calcite: Polymorphs of CaCO 3 in the ancient lime plaster works of south India’s Alampur group of temples that was under submerged condition due to past construction of Srisailam hydroelectric dam on Tungabhadra river just nearby the temples. For the proper examination of the Alampur plaster, we used analytical methods such as onsite observation, petrological thin section, XRF, XRD, FTIR, SEM – EDX and Raman Spectroscopy. The presence of polymorphs of CaCO 3 was confirmed through XRD, FTIR, SEM – EDX and Raman Spectra of the plaster. The occurrence of CaCO 3 polymorphs may be due to the action of invertebrates on initial submergence, self healing of the lime due to wet and dry cycle in the presence of Mg that promoted the formation of polymorphs. Microscopic mineralogical analysis showed mixing of sub-angular to sub-rounded, medium to low maturity sand and coarse silt character aggregates of silica rich lithology. The identification of phthalocyanine blue dye in the plaster by Raman spectroscopy may be part of present day rituals. This work is a holistic approach to find out the composition of ancient lime towards protecting the sand stone masonry of the temple by applying compatible lime plasters to arrest the deterioration. [ABSTRACT FROM AUTHOR]

• Igneous aggregates, mainly granites, showed high PSV and good polishing resistance. • Granite aggregates with altered minerals witnessed poor polishing resistance. • RHD, DH, and DA influence micro-texture deterioration rate (BPN3-BPN6). • PSV showed a good correlation with RHD and DH. • Fundamental mineralogical parameters can better predict BPN3-BPN6 than PSV. The objective of the study presented in the paper is to identify the mineralogical parameters that influence both micro-texture deterioration and Polished Stone Value (PSV), which are the two most important properties of the aggregates that control the pavement skid resistance. The study was carried out on fourteen sources of aggregates which belong to either igneous or metamorphic rock category, the two most commonly used aggregate categories for surface course mixtures in India. PSV of aggregates was determined as per BS EN 1097-8: 2009. To investigate the progressive extent of polishing, the British Pendulum Number (BPN) of the aggregate was determined after every hour of polishing. Simultaneously, the mineralogical parameters were also obtained based on the microscopic observations of the thin sections of the aggregates. From accelerated polishing tests, it was observed that igneous aggregates, especially granites, were found to have relatively high PSV and good polishing resistance. Nevertheless, granite aggregates with altered minerals witnessed poor polishing resistance. Correlation analysis on the combined data for igneous and metamorphic aggregates suggested that the mineralogical parameters such as Relative Hardness (RHD) of aggregates, Differential Hardness (DH) between major minerals within the aggregate, and degree of alteration (DA) influence micro-texture deterioration rate (BPN3-BPN6). PSV showed a good correlation with RHD and DH. It was also noted that altered granite aggregates of igneous type significantly influenced the correlation. In general, it was observed that fundamental mineralogical parameters can better predict BPN3-BPN6 than PSV. [ABSTRACT FROM AUTHOR]

Abstract: Rice husk is a waste product that causes pollution and disposal problem. India is the second largest producer of rice in the world and effective use of rice husk ash in concrete is promising. Silica fume and fly ash are also waste products in some other processes and are excellent mineral admixtures of concrete. The effect of these admixtures on rheological behavior of high performance concrete have been investigated and presented in this paper. It has been observed that yield stress decreases as the replacement level of rice husk ash and fly ash increases. On the other hand, silica fume seems to be a better material for moderate plastic viscosity needed for the design of high performance concrete. For low yield stress and moderate plastic viscosity, blending of equal masses of silica fume and rice husk ash seems to be a suitable admixture at different replacement levels. [Copyright &y& Elsevier]

• SHM experimental campaign conducted on a multi-arch masonry bridge located in India. • Large longitudinal crack on one of the arches detected with considerable crack width. • SHM monitored with crack growth monitoring and tilting of the spandrels. • Application of two different heavy loads (water tank and hydra crane) located in different positions. • Numerical modelling with advanced full 3D approach with adaptive NURBS FEM in limit analysis. The paper presents some SHM results belonging to a wide experimental campaign conducted on a multi-arch masonry bridge located near Mumbai (India), exhibiting a large longitudinal crack on one of the arches and the corresponding advanced numerical evaluations carried out with a NURBS kinematic limit analysis approach, used to assess the stability of the arch subjected to the passage of heavy traffic loads. The masonry bridge is a three-arch structure built during the mid-19th century by British engineers to connect Bombay with the inland of the Indian subcontinent. At present, it is characterized by a heavy state of degradation especially in one of the arches that requires an immediate evaluation of the safety under the passage of traffic loads and possible ideas of interventions to strengthen the structure, in order to avoid the propagation of deep cracks along the longitudinal direction. The adopted SHM includes the crack growth monitoring and tilting of the spandrels under the application of two different heavy loads (a water tank truck and a hydra crane) located in different positions of the arch. Numerical modelling is carried out with a full 3D approach with NURBS finite elements in limit analysis that takes into account the pre-existing crack opening and predicts with great accuracy the ultimate loads in different scenarios and the corresponding active failure mechanisms. From experimental monitoring and numerical simulations results, it is concluded that the bridge is still safe under the passage of traffic loads, but approaches the ultimate limit state for some specific configurations of the loads applied. A refurbishment is therefore needed to avoid any further propagation of the cracks up to collapse. [ABSTRACT FROM AUTHOR]

• Mechanical strength and pore properties are checked with over burnt brick aggregate. • Nonlinear relation is obtained among permeability, porosity and compressive strength. • For single sized aggregates, permeability lie in the range of 1.2–2.1 cm/s. • Prediction equations are made for porosity, permeability and compressive strength. In the search of alternate construction materials, over burnt brick aggregate has enrolled its appellation as a low cost sustainable alternate material. In the north-eastern part of India, especially in Tripura, the shortage of natural stone aggregate has opened up the field for over burnt brick aggregate to be used as an alternate pavement material. This study mainly focuses on the characterization of pervious concrete mixes produced with over burnt brick as coarse aggregate. Pervious concrete, in the recent era, has been considered as the emergent technology due to its prominence as an environmentally and hydrologically sustainable pavement system. In this paper, a series of test samples are produced using various design variables and then the mechanical strength and the pore properties of porous mixes are evaluated. Aggregate gradation, water-cement ratio and the percentage of fine aggregate are chosen as the design variables and their effect in the compressive strength, tensile strength, flexural strength, porosity, permeability, etc. are estimated. The statistical analysis is also carried out using the experimental test data and prediction equations are developed to estimate the porosity, permeability and the compressive strength of the pervious concrete mixes. The predicted equations fitted well and showed a very good agreement with the calculated results. These equations can be directly used for the selection of the mix proportion and the designing of pervious concrete mixes made with over burnt brick aggregate. [ABSTRACT FROM AUTHOR]

• Clear methodology for effective use of C&D waste in concrete is warranted. • Treatment methods for mitigation of weaknesses within RCA and RAC has discussed. • Performance enhancement methods on RCA considering sustainability has analysed. • Present review recommends for the strengthening of attached mortar not the removal. With global increase in construction and demolition, recycling of construction debris as an aggregate can be a vital step towards achieving sustainability in concrete construction. However, a clear methodology for reuse of construction and demolition (C&D) waste in concrete is warranted for its use in practice. This paper reviews the challenges revealed hitherto such as weak interfacial transition zone, high water absorption and presence of micro cracks in the use of C&D wastes as the recycled aggregate (RA). Methods of mitigation of these weaknesses through various treatments have been reported. This review has a special focus on India, a country that generates one of the world's highest quantity of C&D waste. After analysing all the treatment methods, the authors summarize that the strengthening of attached mortar (AM) technique is better than removing of AM, which is also cost-effective, eco-friendly and sustainable. Use of nano-materials and pozzolana along with different mixing methods and application of bio-cement is found to be superior and environmental friendly approach for improving the properties of recycled aggregates. [ABSTRACT FROM AUTHOR]