Explore the vast range of titles available.

Many efforts have focused on the deterioration of historic buildings, and natural hydraulic lime mortar without admixture is less resistant to environmental agencies than a lime mortar with admixtures. A research study has been carried out to study the effect of carboxymethyl cellulose (CMC) and alccofine (AF) with the natural hydraulic lime mortars in improving the hydraulic properties, durability properties, and freeze–thaw resistance. The performance of lime mortars was evaluated with various additives. The experimental results indicated the combined effect of CMCs and AF in lime mortars’ compression testing in different stages. In blended mortars, the early compressive strength was increased. Also, mixed mortar exhibits stronger freeze–thaw resistance with a long healing period. These findings indicate that AF and CMC combination played an essential role in lime mortar (LM) properties, which is generally advantageous for restoration and conservation purposes, especially in historic structures in cold regions.

Heritage structures are valuable monuments that describe the culture and tradition of the country. In today’s world, natural or artificial tragedies alter these historic structures. As a result, restoration was implemented to restore the ancient buildings using modern binding agents to conserve these cultural structures. Rehabilitation can take place only by analyzing the properties of existing structures. The alternative binding additive agent selected can regain the same strength and shape as the heritage structures based on the existing structure properties. Based on these, the restoration of the Alamparai Fort was performed by analyzing the fort materials using mortar strength analysis by core-drilling, double punch test, and small-scale masonry test. The arch properties are also analyzed by performing seismic analysis based on the mortar strength properties. The stability analysis of the organic and existing materials shows that Gur and Haritaki are the best additive agents for restoring the fort. Hence, the fort’s diagonal shear test and seismic modeling were used to analyze the performance of the mortar strength and seismic analysis of these materials. The proposed material strength test results indicate that the Gur and Haritaki are the best additive agents to restore the fort. The fort was restored with these materials; it survived the Nivar cyclone on 26 November 2020.

Additives that change the rheology of lime mortars include starches and starch derivatives that act as viscosity-modifying agents. Amylopectin extracted from potatoes, a long-chain hydrophilic polymer with a high molecular weight that tended to agglomerate, was used as an additive in natural hydraulic lime mortars. The study focuses on how the addition of starch affects the rheology and characteristics of a hardened lime matrix. The study demonstrates that the addition of amylopectin results in a shear-thinning behavior of the lime mortar, improving its workability under shear conditions. The findings demonstrate that the hydraulic lime mortar's amylopectin content increases its elastic properties, directly bearing on its consistency. Calcium starch complexes are formed, which increases the workability of lime mortar and cohesiveness and reduces shrinkage cracks, which makes the material less prone to weathering agent infiltration. Amylopectin increases the hydrophobic properties of modified NHL mortar by creating a barrier impervious to water. The amylopectin develops a thin coating that covers the binder grains uniformly over the mortar's structure, which reduces pore connectivity and restricts water flow. The pores in the modified specimen were blocked by the molecules in the amylopectin, which offered resistance to permeability. The authors of this paper believe that due to the changes it had on the porous structure of lime mortars, a viscosity-modifying admixture based on potato starch could diminish mechanical strength in the short term while increasing durability.

This article presents an innovative study that experimentally investigates the role of amylopectin, extracted from kernels, on the mechanical, physical, and durability properties of natural hydraulic lime (NHL) mortars. Polysaccharides of amylopectin play a major role in increasing the workability of the additive-modified mortar. The amylopectin-modified mortar enhances its compressive strength by 1.68 times compared to the reference mortar. The amylopectin-modified mortar improves its mechanical properties without compromising water absorption and porosity, thus preserving the breathability of the restoration mortar. Amylopectin enhances the hydrophobic property of NHL mortar, forming an outer layer that is resistant to water and salt deposition. The modified mortar’s moisture-holding capacity improves carbonation and reduces drying shrinkage. The polysaccharides of amylopectin enhance the carbonation, regulate the growth of calcite crystals, and result in a denser microstructure, leading to enhanced strength gain. We have also studied the microstructure and morphology characteristics of the modified mortar using XRD, FT-IR, and SEM. We can further extend the investigation to examine the crack capacity of this amylopectin-modified NHL mortar.

In the present study, lime-based mortars were analysed to restore an ancient temple situated near the town of Tiruvannamalai in Tamil Nadu, India. Samples were taken from four different locations at the temple. Various techniques such as acid loss analysis, particle size distribution, XRD, XRF, SEM, FTIR, and TGA were employed to characterise ancient mortars and plasters. The binder-to-aggregate ratio was found to be in the range of 1:2.9 to 1:3.2 by acid loss analysis. The presence of organic additives (carbohydrates, proteins, and fats) identified in the analysis of organics was confirmed by FTIR analysis and TGA. Organic additives were added to strengthen the mortar against environmental degradation. The objectives of this study are to investigate the characteristics of traditional materials and techniques employed in the construction of the ancient temple for effective simulation of the conservation process and protection of the temple. The composition of mortars employed in the construction of the temple and the chemical and mineral composition of the binding ingredients used as organic additives were analysed in this study. The optimum binder-to-aggregate ratio for construction was determined to be 1:3. Restoration lime mortar samples matching the ancient mortars were prepared and the chemical and mineralogical properties of fresh and hardened samples, and their durability properties were also studied. It can be concluded that restoration of the temple can be accomplished by preparing suitable lime mortars but with different organic additives.

The modification of lime mortar to conserve architectural heritage buildings is being widely practiced today. The effect of the mix ratio (B/Ag) on the fresh and hardened state properties of air lime–alccofine mortar using analytical techniques was investigated in this research. Air lime was mixed with alccofine in the ratios of 100:0, 75:25, 50:50, and alkali activation solutions in proportions of 2.5%, 2.75%, and 3% were added to the mix. The XRD, FTIR, and SEM analyses were used to investigate the mineralogical properties of the modified mortar. Thermogravimetric analysis confirms the XRD and FTIR results, which point to strength gain of the mix. TGA confirms the outcome of the XRD analysis and indicated weight loss at around 800 °C, showing decomposition of calcite and release of CO 2 . SEM images validated the presence of calcite and hematite. It was observed that the compressive strength values for the mortar modified with 25% alccofine with alkali activation (2.75%) were 1.76 MPa at 7 days and 2.17 MPa at 28 days and flexural strength values were 0.64 MPa at 7 days and 0.74 MPa at 28 days. When 25% alccofine and 2.75% of activated alkali solution are introduced, the compressive and flexural strengths of the resulting mortar steadily improved and reached the maximum of 1.81 MPa and 0.56 MPa, respectively. The analysis in our study shows that the conventional lime mortar mix made up of air lime and alccofine prepared by alkali activation is a sustainable material in the fresh and hardened states. Therefore, our findings assist in preparing a viable mortar for the restoration of historic masonry structures.

The use of lime mortar to bind historic masonries exists over centuries. Traditionally natural additives are used in the manufacture of lime mortar to enhance mechanical and durability properties. In this research, the performance of natural hydraulic lime 3.5 (NHL 3.5) mortar was enhanced using neem gum as an additive added in different dosages of 0.1%, 0.2%, and 0.3% by weight of water. The modified NHL 3.5 mortar samples were subjected to fresh-state, mechanical, physical, and durability properties. The impact of organic inclusion in the hydraulic lime matrix on their mechanical and physical characteristics has been investigated. The results showed that organics in the lime matrix significantly increased the hydraulic lime's mechanical characteristics due to the organic’s adhesive nature that solidifies on drying, which also bonded sand and lime particles together. Even though the organic inclusion increased the open total porosity, the strength and durability of lime mortar were enhanced because more micropores were in the range of 0.1–1.0 μm, filling the gap between two consecutive lime particles in the mortar. Organic loading reduced the water absorption since the surfaces of the pores are coated with a layer of hydrophobic non-polar molecules of the admixture. The capillary rise is very much reduced with the addition of a hydrophobic admixture. The reduced capillary rise is due to the smaller pores in the modified NHL3.5 mortars due to the active conversion of 15% of macropores into micropores. That inhibited the capillary intake of water /salt solution. Analytical studies such as X-ray diffraction, TGA, and FTIR analysis have confirmed the new element formation in the organically modified NHL3.5 mortar due to the interaction of carbohydrates and fats with lime particles.

The present study characterizes mortars from Thanjavur Palace (Thanjavur, India) to illustrate ancient production methods and the raw materials used. The mineralogical-petrographic composition of mortars was determined using optical microscopy, supported by scanning electron microscopy with energy-dispersive spectroscopy and X-ray powder diffraction. The chemical composition and organic content of the binder were also determined. The aggregate-binder ratio and particle size distribution of the mortars were investigated. Results showed that the composition of both the aggregate and binder varied between mortars. The aggregate consisted mainly of quartz, with small quantities of feldspar and individual grains of limestone and other lithic grains present. The majority of the mortars contained a lime binder, but kaolinite was also identified, indicating a clay binder. Kaolinite primarily occurred in bedding mortars rather than plaster mortars. All samples were in a deteriorated state due to the presence of gypsum and halite. Analysis of particle size distribution confirmed the size of the aggregates to range between 1.18 and 0.3 mm, showing that the aggregates must have been ground in order to allow for the dispersion of binders. Furthermore, biomolecules in the form of carbohydrates, proteins and fats, which could serve as natural admixtures to improve properties in both the fresh and hardened state, were identified in all mortar samples.

India is a rapidly growing country and this created pressure on its natural resources. During its growth and development, different types of wastes are produced through agricultural, industrial, and anthropogenic activities besides increase in energy demand to keep its pace of growth to become a developed nation. Various strategies like landfill, incineration, gasification, and anaerobic digestion (AD) are available to treat as well as to produce energy from the wastes. Production of biogas through AD is one of the best available options due to low energy requirement and eco-friendly nature as compared with other methods. In India, waste to the energy sector may project to a market size of 14 billion ~USD by 2025 with an annual increase of around 7%. In order to capture this untapped source of energy scientific management of waste along with Government policies, schemes and incentives for waste management, renewable energy, agriculture, etc. and their implementations are crucial cornerstones for the promotion of biogas technology and to get renewable energy on sustainable basis. But still a number of challenges are being faced by its stakeholders in India to transform wastes into energy and to secure a clean and green future. Production process of gaseous fuels, management of wastes, its logistics, and recent advancements in Govt. policies and schemes are being discussed in this review article that may help its stakeholders to make India self-reliance in renewable energy along with sustainable growth and development.