Ratio Of Lime Research Articles

Synthesis of calcium ferrite using microwave susceptor heating

ABSTRACT There is a growing interest in calcium ferrite due to its diverse applications, including catalysis, magnetic storage, and environmental remediation. Conventional synthesis methods often involve prolonged heating processes. Microwave heating offers an intriguing alternative, leveraging its ability to induce rapid material synthesis. However, the response of lime and hematite to microwave heating is highly contrastive. This research delves into the synthesis of calcium ferrite under microwave heating, aiming for rapid and efficient formation. Experiments were conducted with or without a susceptor using an equimolar ratio of pure lime and hematite in the form of a pellet. Susceptor heating is necessary for the substances that do not easily absorb microwaves. The experimental results indicated that the calcium ferrite does not form even if the pellet is heated for 50 min without a susceptor. However, with the use of a susceptor, the calcium ferrite forms in 8 min of heating. The X-ray microtomography analysis reveals that the porosity ratios of 6- and 8 min-treated pellets are 2.34% and 2.65%, respectively. Also, most of the pores for all cases lie within 0–250 μm. FE-SEM micrographs also support the formation of a highly porous structure of calcium ferrite for 8 min treated pellet.

Experimental Study on Optimization of Consolidation Parameters of Silty Clay Based on Response Surface Methodology: A Case Study on the Protection and Restoration of the Ming and Qing Dynasty Hangzhou Seawall Site

The preservation of the ancient seawall site is a focal point and challenge in the protection of historical relics along Hangzhou’s Grand Canal in China. This endeavor holds significant historical and contemporary value in uncovering and perpetuating Hangzhou’s cultural heritage. Researchers investigating the Linping section of the seawall site aimed to address soil site deterioration by selecting environmentally friendly alkali-activated slag cementitious materials and applying the response surface method (RSM) to conduct solidification experiments on the seawall soil. Researchers used the results of unconfined compressive strength tests and microscopic electron microscopy analysis, considering the comprehensive performance of soil solidification mechanisms and mechanical properties, to establish a least-squares regression fitting model to optimize the solidification material process parameters. The experimental results indicate that the optimal mass ratio of lime, gypsum, and slag for achieving the best solidification process parameters for the seawall soil, with a 28-day curing period, is 1:1.9:6.2. This ratio was subsequently applied to the restoration and reconstruction of the seawall site, with parts of the restored seawall exhibited in a museum to promote the sustainable conservation of urban cultural heritage. This study provides theoretical support and practical guidance for the protection and restoration of soil sites.

Diurnal, and seasonal dynamics in essential oil content and composition of cultivated Helichrysum italicum (Roth) G. Don

Helichrysum italicum from the Asteraceae family is a small odorous shrub that is distributed in the Mediterranean region different altitudes. However, the species was not naturally found in the flora of Türkiye. Cultivation interest in H. italicum has grownsince its cosmetic and pharmaceutical usage. In the present study, H. italicum plants (seedlings were obtained from the same source) were cultivated in Hatay (Mediterranean, 149 m altitude) and Uşak (Continental, 906 m altitude) cities of Türkiye. Harvestings were done in the spring and autumn, at three different hours of the day (09.00, 13.00, and 18.00) in both locations. Soil samples were analyzed to determine some soil properties in both locations. Harvested aerial plant samples were evaluated for essential oil content and composition with three replicates. The experimental field soils' pH values were similar, however there were differences in the ratio of soil lime and macro-microelements. The essential oil content varied between 0.29 and 0.59% in all examined variables. Generally, neryl acetate and α-pinene were found as a main component in all essential oils. Neryl acetate contents ranged between 8.07 and 36.66%, while α-pinene content was found between 13.93 and 31.18%. In the spring harvest, harvesting in the evening produced higher neryl acetate in the continental environment, whereas harvesting at any time of day did not affect the amount of neryl acetate in the Mediterranean climate. In the autumn harvest in the Mediterranean environment, the neryl acetate content was higher in the morning harvest, while neryl acetate content in autumn was comparatively low in the continental climate. Examining the seasons has shown that, in a Mediterranean environment, harvest time is not very significant, but in a continental climate, spring harvest could be favored.

Study on the strength characteristics and micro-mechanism of modified solidified red mud

The residue generated during the production process of alumina, known as red mud, is a type of solid waste. The engineering properties of red mud can be significantly enhanced through the modification and solidification using inorganic materials. This study primarily utilized red mud as the raw material, supplemented with fly ash, lime, and clay, to conduct a solidification experiment of red mud. Orthogonal tests with three factors of two ash ratio (ratio of lime to fly ash), two ash content (total lime and fly ash), and red mud types were designed to study the changes of different ratios and maintenance conditions, etc., on the engineering properties of red mud. In addition, the micro-mechanisms of modified red mud were investigated by means of XRF, XRD, SEM and EDX. The results show that for optimum moisture content, red mud types are the most important influencing factor and for maximum dry density, two ash content is the most important influencing factor. For strength characteristics, the optimum two ash ratio was 1.5:1, the optimum two ash content was 50%, and the optimum red mud types were 70% CRM (red mud made of Chalco Shandong Co., Ltd) mixed with 30% clay. The addition of lime, fly ash, and clay improves the temperature shrinkage coefficient of the red mud. Through the analysis of microscopic composition and structure, it can be seen that goethite (α-FeO(OH)) and magnetite (γ-Fe2O3) in the red mud reacted with the modified materials to generate crystalline aluminosilicate and amorphous hydrated silicate gel, and these products together with the original calcium carbonate (CaCO3), tricalcium aluminate (Ca3Al2O6) and garnet (Ca3TiFeSi3O12) in the red mud which have certain strengths enhance the structural strength of the modified red mud. The optimum ratio obtained from the combined test results was lime: fly ash: CRM = 30:20:50. Therefore, using lime, fly ash and clay as modified materials can greatly enhance the engineering properties of red mud and realise the resourceful use of red mud.

Eco-friendly low-carbon manganese ferroalloy production for cleaner steel technologies

Global steel production, a major contributor to anthropogenic carbon dioxide, heavily relies on manganese, a key ingredient that significantly impacts the carbon footprint during the production of high-carbon ferromanganese. A single-step generation of low-carbon ferromanganese (LC-FeMn) from manganese ore in an electric arc furnace (EAF) was investigated. The theoretical and experimental investigations helped to balance the required and supplied energy. The process sustainability was predicted based on the enthalpy of the reaction. Pre-reduction of manganese ore decreased energy consumption in the smelting process and saved raw materials costs. The simulation studies revealed a significant effect of lime and silica on the slag-metal equilibrium. It further confirmed the best-reducing condition with the basicity 1.5–1.77 by smelting tests in EAF. Experimental results showed an optimal charge mixture comprising appropriate ratios of ore:SiMn:lime ratio, producing a standard-grade product. Simultaneous melting and smelting sensibly used the exothermic heat, consuming 410–880 kWh/ton, much lower than the international benchmark, i.e. approximately 2000 kWh/ton. The characterization of resulting slags corroborated the advantages of the manganese ore pre-reduction on the energy and reductant consumption, alloy grade, and slag characteristics. The present study's findings can potentially contribute to the ongoing low-carbon initiatives of steel.

Analysis of physical characteristics and mechanism of retarder to stratified cemented backfill

The stratified structural plane caused by stratified backfill will reduce the strength of backfill, and the introduction of retarder will make up for the defect. Three retarders, sodium tripoly-phosphate, citric acid and sucrose, were introduced. After determining the optimal dosage of retarder, they were added into the filling slurry with a ratio of lime to sand of 1:6 and a mass concentration of 75%. Based on the hydration reaction mechanism and damage mechanics theory of cement, the setting time test and uniaxial compressive strength test were carried out. With the help of scanning electron microscopy and X-ray diffraction, the influence mechanism of retarder on the physical characteristics of stratified cemented filling was investigated.The main research contents and achievements are as follows:. The results showed that the three retarding agents can delay the setting time of the cement filling slurry, and the retarding effect is sucrose > citric acid > sodium tripolyphosphate. The addition of retarder can improve the uniaxial compressive strength and integrity of stratified consolidated backfill, and the best filling interval time (FIT) is 12 h. Appropriate addition of retarder will increase the amount of cement hydration products, make the structure of hydration products more dense, reduce the formation of stratified structural plane, and help to improve the strength of stratified cemented backfill.

Energy-saving technology of silicate pressed material with use of micro-porous silica-earth raw materials

Purpose. Research on the possibility of producing a silicate material that hardens under reduced parameters of autoclave processing, due to the introduction of natural zeolite into the raw material mixture. The methods. To solve the problems set in the work, following methods were used:generalization and analysis of theoretical and experimental data of domestic and foreign authors; analytical studies of raw materials (chemical, mechanical and physical-mechanical methods); laboratory experiment using physical and mechanical tests. The study of the properties of raw materials was carried out according to standardized methods. Findings. It has been proven that natural zeolite is an effective component of silicate pressed materials for reducing heat energy consumption during their autoclaving. It was established that with a low zeolite content, the compressive strength of lime-zeolite stone practically does not differ from the strength of limestone-sandstone. A study of the influence of the autoclave treatment regime on the strength of silicate pressed concrete, which was made using a lime-zeolite binder, was carried out. It has been experimentally confirmed that the strength-to-strength ratio of pressed silicate material on a lime-zeolite binder (compared to a similar pressed silicate material on a lime-sand binder) depends to a lesser extent on the water vapor pressure during autoclaving. The originality. The dependences of the compressive strength limit of samples-beams made of lime-zeolite binder at different mass ratios of lime:siliceous component, as well as the dependence of the compressive strength limit of silicate pressed materials on a lime-zeolite binder on water vapor pressure during autoclave processing. Practical implementation. The results of the research can be used at enterprises of the building materials industry in the production of silicate bricks. Replacing natural quartz sand with natural zeolite reduces the production cost of lime-zeolite binder, and the reduction of water vapor pressure during autoclaving of silicate pressed material on lime-zeolite binder reduces the consumption of high-value natural gas.

Effect of Active Lime on the Availability of Metal Micronutrients

The low solubility of minerals containing metal micronutrients such as Fe, Zn, Cu, and Mn in alkaline or lime-rich soils adversely affects plant development in these soils, leading to significant yield losses. This study was conducted to determine the effects of active lime on metal microelement availability in calcareous soils. The analysis of 55 soil samples taken from Narlı Plain in Kahramanmaraş Province revealed a significant positive correlation (r=0.95**) between active and total lime values. The study also indicated that an average of 58% of total lime was present in the active form. Furthermore, it demonstrated that as total lime increased, the proportional amount of active lime decreased. The points where the ratio of active lime to total lime is highest are observed to have low total lime contents. As the total lime content increases, the ratio of active lime to total lime decreases. This is thought to be related to the measurement of relatively higher active lime contents as the calcium on exchangeable surfaces passes into solution when the total lime is low. Therefore, this situation calls into question the reliability of active lime analysis at low total lime contents. With the increase in total lime content, this relative effect disappears and more reliable results are obtained. While active and total lime values showed similar correlations with Mn and Cu, Fe showed a higher correlation with active lime than with total lime. Active lime did not exhibit superior predictability compared to total lime when explaining the utility of metal microelements, excluding iron.

Biological feasibility of discharge a local WTTP sludge to sewer network and centralized WWTP; a case study: Tehran, Iran

Over the recent years, ever-increasing population growth and higher wastewater production has been a challenge for decentralized wastewater treatment plants (WWTPs). In addition, sludge treatment due to high cost for equipment and place make authorities to find a sustainable approach in both of economical and technical perspectives. One of the proposed solutions is transferring the sludge produced from decentralized WWTP to centralized WWTP. However, the appropriate proportional ratio of raw sludge to raw sewage is a challenge, otherwise, it make anaerobic conditions and sewage rotting along the sewer network based on permissible limit of dihydrogen sulfide (H2S) gas (5 ppm). In the present study, seven reactors with different ratios of sludge to raw sewage (0, 15, 20, 25, 50, 75, 100) were used to stimulate the feasibility of transferring Shahrake Gharb WWTP sludge along the wastewater transfer pipe to the centralized sewage treatment south Tehran WWTP plant in Tehran, Iran. The septic situation and H2S emission of different reactors within 7 h (Time to reach the compound in the south treatment plant) was analyzed by gas meter. The results indicated that the optimum ratio of sludge to raw sewage was 15% without H2S production during 7 h. In addition, due to the high volume of sludge produced by the Shahrake Gharb WWTP, the optimal ratio of lime to total solids (TS) in sludge (gr/gr) (0.6) increased the sludge loading rate from 15 to 30% without any H2S emission during the stimulation study period. Therefore, the lime stabilization and transfer of sludge from a decentralized WWTP to a centralized WWTP is a feasible way to manage the sludge and enhance the treatment capacity in local WWTP.

Investigation of cementitious composites reinforced with metallic nanomaterials, boric acid, and lime for infrastructure enhancement

<abstract> <p>Nanomaterials integration within construction materials could promote the generation of more sophisticated structural materials, as it imbues reinforcement at the nanoscale. This research adopted experimental approaches to assess the influence of metallic nanomaterials on the performance of cementitious composites with various ratios of boric acid (1%, 3%, and 5% by sand's weight) and lime (0.5%, 1.5%, and 2.5% by sand's weight), respectively, for use in construction infrastructure facilities. This research provides valuable insight into the potential of using boric acid and lime as well as metallic nanomaterials to strengthen cement-based composites. Initial curing stages revealed a notable decrease in compressive strength attributed to the inhibitory effects of boric acid and lime on cement hydration. However, the introduction of TiO<sub>2</sub> nanoparticles demonstrated significant enhancements in compressive strength and durability. Statistical analysis emphasized the significance of nanomaterials in augmenting compressive strength, with implications for long-term performance. This study has shown that the addition of nano-titanium dioxide TiO<sub>2</sub> can significantly enhance the compressive strength of Portland cement mortars, particularly when used in conjunction with appropriate ratios of boric acid and lime. The results of the 7 days test indicated that the inclusion of boric acid and lime in the cement mortars significantly decreased the compressive strength. However, the addition of nano-TiO<sub>2</sub> to cement mortars containing 1% boric acid and 0.5% lime resulted in a 31-fold increase in compressive strength compared to cementitious composites without nano-TiO<sub>2</sub>. In contrast, the compressive strength significantly increased by 1.2 times, 85.3 times, and 65.1 times, respectively, after 56 days for the addition of boric acid (1%, 3%, and 5%) with lime (0.5%, 1.5%, and 2.5%), respectively, in the presence of nano-TiO<sub>2</sub>, compared to the 7 days strength. The results also illustrated that, in general, the incorporation of various types of nano-TiO<sub>2</sub> into cementitious composites containing boric acid and lime increases their compressive strength as the ratios of boric acid and lime increase, as long as sufficient curing time is allowed.</p> </abstract>

Development of mathematically motivated artificial intelligence models for the prediction of carbonate rock lime saturation factor for cement production

Predicting the cement lime saturation factor (LSF) is vital in cement production as it determines the optimal ratio of lime to other components. This factor affects the quality and strength of concrete, enabling efficient resource utilization, cost control, and environmentally sustainable practices in construction and infrastructure projects. The laboratory tests to determine the elemental composition of cement material is time-consuming and costly. However, limited research has suggested that there is a correlation between parameters obtained from elemental and proximate analyses of these materials. In this study, some predictive models of the elemental composition of carbonate rock using soft computing and regression analyses have been developed from chemical database from 7 formations in Nigeria. These formation includes carbonate deposit in Ikpeshi (Edo State), Ubo River area (Edo State), Itobearea (Kogi State), Igarra (Edo State), Nsofang (Ikom) Igue (Edo State), and Ewekoro (Ogun State). One hundred and forty-four (144) samples including parameters of elemental and proximate analyses were used during the analyses to develop multiple prediction models. Dependent variables for multiple prediction models were selected as carbon, hydrogen, and oxygen. Using Calcium oxide, magnesium oxide, loss of ignition, and the ratio of calcium oxide to magnesium oxide as independent variables, three different prediction models were developed for LSF as the dependent parameter using multilayer perceptron (MLP), least square support vector machines (LS-SVM), Multivariant regression (MVR) and hunter point Backpropagation-artificial neural network (HPBR-ANN) techniques. In addition, a routine for selecting the best predictive model was suggested in the study. The reliability of the established models was tested by using various prediction performance indices and the models were found to be satisfactory. Therefore, the developed models can be used to determine the cement production lime saturation factor of carbonate rock for practical purposes.

Deep insertion of lime into acid organic soils

Organic (peat) soils are inherently acid in their natural state with soil pH levels that decline from 4.5 – 5.0 in the surface layer of 0 – 75 mm to 4.0 - 4.5 at a depth of 400 mm. Traditionally lime has been surfaceapplied and incorporated into the lower soil layers bycultivation. An alternative method of inserting 3 - 4 t/ha of lime down to 400 mm soil depth was tested on a developing Waikato deep Moanatuatua Organic soil. When two-thirds of the lime was placed within the 300 - 400 mm layer and one-third within the 200 - 300 mm layer in summer 2021, soil pH in the 200 - 300 mm layer decreased from 5.6 in 2021 to 5.3 in 2023 and significantly increased from 4.2 to 4.9 in the 300 – 400 mm layer over the same time period. Reversing the ratio of the lime rate into the two layers resulted in asignificant increase in soil pH from 4.5 to 5.3 in the 200 – 300 mm layer and a non-significant increase from 4.2 to 4.6 in the 300 – 400 mm layer. Generally, there were corresponding decreases in soil exchangeable aluminium (Al) concentration in those layers. The ratioof lime insertion rate had no significant effect on rooting depth between years. There was a moderate correlation between soil pH and exchangeable Al when measured at depths of 0 – 400 mm. These interim results indicate that the deep insertion of lime into an acid Organic soil was effective in increasing soil pH and reducing soil Al concentration in the lower soil layers in the two years after the lime was inserted.

Physical-Mechanical Properties of Light Bark Boards Bound with Casein Adhesives

Based on the background of the limited availability of raw materials in the forestry and timber industry, increased attention applies to sawmill by-products and their potential for future applications. Within the present research, the suitability of a natural binder based on different casein sources, superficially lean curd with different lime ratios, for the production of bark insulation panels from larch bark (Larix decidua) in fraction 12.5–4.0 mm with densities below 500 kg/m³ were discussed and physical and mechanical properties evaluated. In order to obtain a benchmark, control boards bound with powdery casein and urea-formaldehyde resin were fabricated. The evaluation of physical-mechanical characteristics indicated the lean curd panels to be competitive with the references and commercially available insulation materials, whereby higher values could be achieved consistently with a lower lime content of 20% compared to 31%. The best moisture resistance and water absorption were observed with a lime ratio of 31%, whilst thickness swelling and mechanical characteristics were best with a lime content of 20%. Particularly with regard to mechanical properties, panels containing a low proportion of lime in the lean curd blends delivered convincing results, e.g., with an average IB of 0.19 N/mm2, MOR of 1.43 N/mm2 and C of 1.70 N/mm2. In terms of thickness swelling, lean curd adhesives generated unsurpassed values of approximately 11% compared to the casein and urea-formaldehyde references. Additionally, as described in the relevant literature, a considerable influence of density on the mechanical behavior of composite materials was observed. Partly, the lime content significantly influenced the panel properties. The study proved that natural binders based on lean curd and lime are suitable for the production of bark insulation boards and represent a serious alternative to synthetic, oil-based adhesive systems. The results are promising with regard to the market situation due to the availability and pricing of raw materials and technical requirements and demonstrated great potential for further research efforts.

Mechanical and Thermal Conductivity Study of Inorganic Modified Raw Soil Materials Based on Gradient Concept

Based on the inorganic modification of raw soil materials by using cement, fly ash, lime and other admixtures, the influence of modified jute fiber content on the strength of raw-soil-based wall materials was studied. The effects of the gradient distribution of inorganic admixtures on the mechanical properties and thermal conductivity of raw-soil-based wall materials were studied and compared by designing the gradient distribution and homogenous distribution of admixtures in raw soil materials. The results show that when the mass ratio of raw soil, sand, cement, fly ash and lime is 30:10:5:3:2, the compressive strength and flexural strength of the modified raw soil specimen at 28 d are 6.4 MPa and 2.9 MPa, respectively; on the basis of the further addition of 0.8 v% jute fibers, the strength can still be enhanced by 20% and its thermal insulation properties will also be improved. Gradient design can further improve the mechanical properties of modified raw-soil-based wall materials and can weaken the loss of its inherent thermal insulation function.

Variables that contribute to tabia's high mechanical strength — A study using traditional residential flooring tabia from Zhejiang, China

Tabia has a long history of application in China, particularly as traditional residential flooring. In this work, we analyzed traditional residential flooring tabia samples from six residential flats in Zhejiang Province, China, to determine its composition and physical properties. We performed surface Leeb hardness test, compressive strength test, specific density and total porosity test, component composition test, sand and clay grain size distribution test, organic additives test, SEM, and XRD tests, capillary water absorption rate test, freeze-thaw damage test for the tabia samples. Results showed that these residential flooring tabia samples exhibit high compressive strength that can reach as high as 10 MPa. Furthermore, additional analysis determined that the high compressive strength is a function of the following criteria: 1) high density; 2) suitable mass ratio of sand, lime, and clay; 3) the appropriate sand particle size ratio; and 4) formation of hydrated calcium silicate (C-S-H). Moreover, sticky rice and egg white were also detected in the residential flooring tabia samples. The tabia's water absorption coefficient rate decreases with their density. The freeze-thaw resistance of tabia is related to many factors such as calcite content, density and porosity, microstructure. The data obtained from this study will provide guidance for conservators in the protection and restoration of tabia relics.

A Comparison Study of Nickel Laterite Reduction using Coal and Coconut Shell Charcoal: A FactSage Simulation

Replacing metallurgical coke with greener material is a long-term challenge in pyrometallurgy. With the fact of biomass abundance in Indonesia, the usage of bio-char as a replacement for coke resulted from coal has been an intensive study. This study compared the performance between anthracite coal and coconut shell charcoal for nickel laterite reduction using the Equilibrium module on FactSage software simulation. The simulation was done by inputting a 4:4:1:20 weight ratio of nickel laterite ore, reductant (coal or coconut shell charcoal), lime and air, respectively. The temperature studied was 1300

Preparation of Cementitious Material with Wet Fly Ash by Hydrothermal Reaction and Calcination

A large amount of wet-discharged fly ash has caused serious harm to the ecological environment, so the utilization of fly ash has received attention. This paper analyzes the formation of products of fly ash–lime system under the autoclave process by X-ray diffraction (XRD) analysis and thermogravimetric–differential thermal (TG-DSC) analysis. The hydrothermal reaction product generation was quantitatively analyzed using the hydrochloric acid selective dissolution method to quantify the degree of reaction of fly ash in the pressure evaporation specimens in combination with the reaction degree of lime in the autoclave specimens. The hydrothermal reaction products were calcined and hydrated, and the mineral composition of the calcined products and the mechanical and microstructure of the hydrated products were analyzed. The results show that hydrothermal reactions occur in the fly ash–lime pressure evaporation system to produce C2SH, C3AH6, C3ASH4, and other products. The optimum ratio of lime is 22%, and the appropriate autoclave parameter is 140 °C for 8 h. Under this condition, the reaction degree of fly ash is 15.39%, the reaction degree of CaO is 78.63%, and its f-CaO value is 4.93%. The formation of C2SH in the hydrothermal reaction ranged from 14.33% to 18.53%, and the formation of C3ASH4 ranged from 14.06% to 15.26%. The hydrothermal reaction products were calcined at 850 °C for 1.5 h to produce new gelling materials with gelling phases, such as C12A7, α’L-C2S, β-C2S, and C2AS. The compressive and flexural strengths of the new gelling materials reached 34.4 MPa and 6.4 MPa, respectively, at the age of 180 days.

Improvement of Gypsiferous Soils Properties by Hydrated Lime in the Najaf City, Middle of Iraq

This study includes the effect of lime addition on the engineering properties of gypseous soil taken from a part of the Najaf- Karbla plateau (52, 48, 72% gypsum). Also this study shows increase in the proportion of gypsum in the soil in the northwest direction of the study area. Maximum dry density and optimum moisture content (2.065, 2.025 and 2.003) at 15%, 14% and 15% respectively for the three samples. The maximum dry density decrease while optimum moisture content increases with increasing ratio of hydrate lime. The results show that the gypscous soil becomes non - plastic when treated by > 3 % of hydrated lime. Cohesion Force, with the increase in the percentage of lime from 3% to 6%, after which it decreases as the percentage addition of lime to reach zero when the addition became 9%. The reason for this is that the lime increases the cohesion strength between molecules to the limit of adding 6%, then the cohesion decreases to zero when 9% is added lime. The results of a liquid limits are changed and the soil becomes more liquidity limit when it's treated due to the hydrated lime increases liquid limits significantly, and it becomes clear that the limit of liquidity. After which the lime molecules work to separate the molecules from each other, and the cohesion force decreases. It is also noted that the internal friction angle decreases with the increase in the percentage of lime.

Effects of Chemical Stabilisation of Eggshells-Lime and Fly-Ash-Cement on the Structural Strength of Subgrade Soil in Rural Roads

This study examines the chemical compositions of eggshell powder (ESP) and lime as the soil stabilisers and compared with the compositions of cement and fly-ash to understand the optimal distribution of chemical stabilisers maximizing the bearing capacity and structural integrity of subgrade soil. Two chemical compositions of ESP-lime and fly-ash-cement with 2%, 4%, 6% and 8% of total mass of soil sample were mixed with 6% and 4% constant ratio of lime and cement, respectively.

Behaviour of masonry lateral loaded walls made with sediment-based bricks from the Usumacinta river (Mexico)

A feasibility study on Usumacinta River sediment-based bricks for resilient housing adapted to both climate change and seismic risks is performed on laterally loaded reduced-scale walls. Mortar formulations with different volume ratios of lime and sand (2/1, 1/2, 1/4, 1/6) are prepared while different types of sediment-based bricks are thoroughly investigated, manufactured and strength characterized. Commercial fired bricks as reference bricks completed the set of bricks tested (FRS: Fired River Sediment-based brick (at 850 °C); LRS: Lime treated River Sediment-based unfired brick (1.5% of lime addition); NRS: Natural fiber Reinforced river Sediment-based unfired brick and FR: commercial Fired Reference brick made without sediment). Walls of different sizes were built with these types of bricks and mortars. Tests under lateral in-plane loads of walls i.e. pushover tests , were conducted. The most significant results are as follows:(1) the addition of lime increases the strength of the mortar; (2) the wall size effect is observed for wall built with reference bricks (FR) and mortar ratio (1/2), where, large walls (LW), intermediate walls (IW) and small walls (SW) exhibiting maximum load of about 1200 N, 440 N and 260 N respectively. Rocking failure mode is the most observed unlike shear and sliding mode which are rarer. (3) maximum load measured during a pushover test performed on walls with sediment-based bricks provides a satisfactory average of 130 N, which exceeds the strength recommended for light buildings; The failure mode is sliding for fired bricks and rocking for unfired bricks. (4) the sediment-based bricks walls give an interesting ductility to pushover test while (2.6–40). These results show promising perspectives on the possibility of using the Usumacinta River sediment-based bricks in walls for light constructions under seismic loading. • The use of Usumacinta River sediment-based bricks is suitable in light buildings (80). • Fired, unfired: lime treated and fibered sediment-based bricks are used for wall tests (86). • The sediment-based brick wall gives satisfactory pushover resistance (68). • The ductility of the walls demonstrates significant seismic resistance (69).