Evaluation Of Durability Research Articles

Effect of Zr-glass fibers waste on the mechanical, structural, and durability of eco-friendly geopolymers based on natural pozzolan: A Box-Behnken design approach

Geopolymer (GP) materials are attracting increasing interest as a promising alternative to conventional cement-based materials, due to their beneficial characteristics. This article presents the preparation of two series of GP composites based on natural pozzolan (Pz), reinforced with varying percentages (0, 0.5, 1, 1.5, and 2 %) of short fiberglass waste rich in zirconia (Zr-GFW). Two alkaline activation solutions were used with a 1:1 ratio: NaOH (10 M): Na2SiO3 for the first series, and NaOH (12 M): Na2SiO3 for the second series. The effect of Zr-GFW incorporation on the structural, physical, mechanical, and chemical properties was investigated. Besides, a comparison between the two series with the different concentrations of alkaline solutions was also discussed. XRD analysis shows that no significant reaction occurred between zirconia and Pz-based GP matrix. The results show that a 1 % Zr-GFW is sufficient for excellent mechanical strength, up to 65 MPa, and good physical properties. Furthermore, based on the Box-Behnken design statistical method, the developed response surface methodology model shows a strong fit to the experimental data, with high values of R² (0.9998). In this model, the compressive strength studied is 64.28 MPa. After exposure to an 80 % solution of acetic acid for 60 days, the evaluation of chemical durability showed that the dense structure of the studied GP composites resisted the acid attack tests, as confirmed by SEM analysis. The percentage weight loss (%WL) of the GP composites ranges from 14.66 % to 16.15 %, resulting in a decrease in compressive strength of up to 55 %. However, this reduction is better than several previous works. The findings suggest that these GP composites not only contribute to waste management but also enhance the energy performance of buildings.

Hybrid Interventions for Pulmonary Vein Stenosis: Leveraging Intraoperative Endovascular Adjuncts in Challenging Clinical Scenarios.

Background: Pediatric pulmonary vein stenosis (PVS) is often progressive and treatment-refractory, requiring multiple interventions. Hybrid pulmonary vein interventions (HPVIs), involving intraoperative balloon angioplasty or stent placement, leverage surgical access and customization to optimize patency while facilitating future transcatheter procedures. We review our experience with HPVI and explore potential applications of this collaborative approach. Methods: Retrospective chart review of all HPVI cases between 2009 to 2023. Results: Ten patients with primary (n = 5) or post-repair (n = 5) PVS underwent HPVI at median age of 12.7 months (range 6.6 months-9.5 years). Concurrent surgical PVS repair was performed in 7/10 cases. Hybrid pulmonary vein intervention was performed on 17 veins, 13 (76%) with prior surgical or transcatheter intervention(s). One patient underwent intraoperative balloon angioplasty of an existing stent. In total, 18 stents (9 bare metal [5-10 mm diameter], 9 drug eluting [3.5-5 mm diameter]) were placed in 16 veins. At first angiography (median 48 days [range 7 days-2.8 years] postoperatively), 8 of 16 (50%) HPVI-stented veins developed in-stent stenosis. Two patients died from progressive PVS early in the study, one prior to planned reintervention. Median time to first pulmonary vein reintervention was 86 days (10 days-2.8 years; 8/10 patients, 13/17 veins). At median survivor follow-up of 2.2 years (2.3 months-13.1 years), 1 of 11 surviving HPVI veins were completely occluded. Conclusions: Hybrid pulmonary vein intervention represents a viable adjunct to existing PVS therapies, with promising flexibility to address limitations of surgical and transcatheter modalities. Reintervention is anticipated, necessitating evaluation of long-term benefits and durability as utilization increases.

A laboratory study on the durability of limestone wastes in harsh environments for their suitability as aggregate in concrete

One of the critical environmental issues in the Chegeni area (Lorestan Province, western Iran) is the production of a large volume of limestone wastes during the quarrying operations. Releasing limestone wastes in the areas neighboring the quarries has caused visual damage to the environment, and adverse effects on the quality of the soil, running water, and groundwater used for agricultural and drinking water purposes. One solution to this issue can be recycling limestone wastes to produce building materials. In the present study, a comprehensive laboratory program is planned for the durability evaluation of the limestone wastes under harsh environments for their suitability as aggregate in concrete. For this purpose, five aging tests, including freeze-thawing (F-T), salt crystallization (SC), acid attack (AA), wetting-drying (WD), and heating-cooling (HC), were conducted on the limestone sample up to 60 cycles. After every 10 cycles, the physico-mechanical characteristics of the sample, including porosity (n), Brazilian tensile strength (BTS), point load index (PLI), and P-wave velocity (Vp) were determined. Moreover, the pores structure modification of the sample subjected to aging tests was examined through scanning electron microscopy (SEM). Data analyses revealed that the sample is highly vulnerable to the AA and SC processes but is durable against FT, WD, and HC actions. These results were in good agreement with the SEM data such that the sample exposed to AA and SC underwent more changes in their pore structure compared to FT, WD, and HC. Among the physico-mechanical characteristics, the Vp and PLI had the highest and the lowest accuracy, respectively, in the durability evaluation of the sample exposed to aging tests. Based on the data analysis, limestone wastes can be used as aggregate in concrete in environments with the possibility of FT, WD, and HC. However, this type of concrete is not suitable for conditions with occurrences of the AA and SC. Finally, in addition to reducing the environmentally harmful impacts of the study area, using limestone wastes as aggregate in the construction of concrete can also be a practical solution for sustainable development from an economic viewpoint. The results of the present study can be used for assessing limestone wastes produced in other areas of Iran and the world.

Durability evaluation and lifetime prediction of recycled coarse aggregate self-compacting concrete after freeze-thaw and sulfate erosion coupling

This paper aims to study the durability of recycled coarse aggregate self-compacting concrete (RCASCC) after being subjected to freeze-thaw and sulfate coupling. The durability comprehensive evaluation index of RCASCC based on the entropy weight method was defined, and the variation law of the durability comprehensive evaluation index concerning RCA substitution rate, freeze-thaw environment, and coupling frequency was obtained. GM (1, 1) model based on grey system theory was used to evaluate the durability of RCASCC under the coupling effects of freeze-thaw and sulfate attack. The results show that there are some differences in the accuracy of the four GM (1, 1) models. It is recommended that the EGM model can be used to predict the durability of the RCASCC under the coupled effects of freeze-thaw and sulfate erosion. Moreover, the working life of RCASCC under the coupling effects in the outdoor environments of northeast, north, and northwest China was calculated, when the comprehensive evaluation index of durability decreases to 75% as the failure criterion. A multi-criteria analysis employing TOPSIS and VIKOR methods was conducted to evaluate the durability of RCASCC under these coupling effects. A multi criteria analysis was conducted on the durability of RCASCC under the coupling effects of freeze-thaw and sulfate erosion using TOPSIS and VIKOR methods. Under these two rankings, the splitting tensile strength is the index that changes the most after coupling effects, while the compressive strength changes relatively little. The importance of dynamic elastic modulus and weight is different due to different materials and evaluation methods. RC100-H typically exhibits the largest variation, while NC-H and RC50-NM typically exhibit smaller variations.

Influence of the colloidal nano silica on the bonding of new-to-old concrete interface

The quality of the interface between new and existing concrete is a crucial factor that significantly affects the effectiveness of concrete patching and rehabilitation. This transitional zone between concrete layers exhibits inherent porosity and diminished structural integrity, which can potentially serve as the origin of cracks and fractures. The presented study was conducted to evaluate the quality of the new-to-old concrete interface when colloidal nano silica (CNS) is used. Apart from directly blending CNS with concrete materials, this study uniquely employed CNS as a surface agent to enhance the quality of the interface. The microstructure, mechanical bonding performance and chloride resistance property were evaluated on samples with new-to-old interface. By microstructural analysis, it was found that the porosity at the interface region was reduced from 24% to less than 16% when CNS was directly added into the concrete. Due to the improved hydration and the formation of a denser and uniform interface, a higher bonding strength was therefore achieved. Improvement in bonding strength was also found when CNS was used as an agent on the surface of the old layer, due to the precipitation and pozzolanic reaction of the nano silica particles. There were no apparent signs of increased porosity at the interface region as the precipitation of nano silica particles densified the cement matrix. Additionally, the solid precipitates generated frictional force, increasing the bonding strength under shearing loading. However, due to the lack of cohesion, the nano silica precipitates couldn’t sustain the tension under flexural test. Durability evaluation showed that the chloride resistance of the double-layer sample was effectively enhanced as the quality of the interface was improved with the use of CNS, especially when the surface method was used. The outcome of this study provides insight into the use of low CNS dosage to improve the new-to-old concrete interface and sheds light on the use of CNS as an interface agent.

Evaluation of the Durability of Concrete with the Use of Calcined Clays and Limestone in Salinas, Ecuador

This study aims at the evaluation of different formulations of concrete made with calcined clays and limestone (LC3 cement) exposed to aggressive environments. The study includes the evaluation of fresh and hardened properties and a comprehensive evaluation of durability over 24 months. The inclusion of calcined clays in cement increases the specific surface area of the cements, and thus the water demand. However, the high reactivity of calcined clays compared to any other pozzolan, and the synergy that occurs with limestones, enables the use of cements with very low clinker content that achieve strengths similar to those of Portland. Comparisons of LC3 formulations with Portland cement and with concrete containing silica fume prove the superiority of calcined clays in terms of strength and durability. The best results are obtained with LC3-50 cement with 50% clinker produced through co-grinding. Results of concrete made with a blend of 70% Portland cement with 30% LC2 (60% calcined clay, 35% limestone, 5% gypsum, separate ground) are also promising. All concretes made with LC3 show good durability in terms of the results of effective porosity, chloride permeability, and resistivity tests.

Evaluation of the Physical Durability of Merdeka Basketball Club Athletes

ABSTRAK Penelitian ini dilakukan untuk mengetahui bagaimana daya tahan yang dimiliki oleh di Atlet Basket putra pada club Merdeka di Rejang Lebong. Penelitian yang dilakukan menggunakan metode deskriptif kuantitatif. Alat pengumpulan data pada penelitian ini adalah multistage fitness test. Subjek dari penelitian adalah Atlet Putra yang yang menjadi Anggota Club Merdeka di Rejang Lebong yakni berjumlah sebanyak 15 orang atlet basket putra club merdeka. Analisis data yang digunakan yaitu analisis deskriptif dengan teknik persentase, dan tes yang digunakan yaitu berupa multistafe fitness test atau bleep test. Berdasarkan hasil dari penelitian yang sudah dilakukan didapatkan bahwa daya tahan fisik yang dimiliki oleh Atlet Basket Club Merdeka di Rejang Lebong 7 orang atlet dalam kategori cukup dengan persentase 47%, sedangkan 6 orang dalam kategori baik dengan persentase 40% dan 2 orang atlet dalam kategori sangat baik dengan persentase 13%. Dengan hasil tersebut berdasarkan norma standarisasi, dapat disimpulkan bahwa kemampuan vo2max atlet basket putra club merdeka di Rejang Lebong dinyatakan dalam kategori cukup, baik, dan sangat baik. Kata Kunci : ABSTRACT This research was conducted to find out the endurance of male basketball athletes at the Merdeka club in Rejang Lebong. The research was conducted using quantitative descriptive methods. The data collection tool in this research is the multistage fitness test. The subjects of the research were male athletes who were members of the Merdeka Club in Rejang Lebong, namely 15 men's basketball athletes from the Merdeka Club. The data analysis used is descriptive analysis using percentage techniques, and the test used is a multistafe fitness test or bleep test. Based on the results of research that has been carried out, it was found that the in very good category, the abdominal muscle strength of female athletes was in physical endurance of the Merdeka Basketball Club athletes in Rejang Lebong is 7 athletes in the fair category with a percentage of 47%, while 6 people are in the good categ ory with a percentage of 40% and 2 athletes are in the very category good with a percentage of 13%. With these results based on standardization norms, it can be concluded that the vo2max ability of men's basketball athletes at the Independent Club in Rejang Lebong is stated in the categories of fair, good and very good. Keywords: Baskerball, Endurance, MFT

Moisture and mould growth risk of cross-laminated timber basement walls: Laboratory and field investigation

Reinforced concrete is a commonly used material for constructing basements in low-rise buildings or residential houses in Canada, and as the use of cross-laminated timber (CLT) advances, the door to think of an alternative basement material to offset greenhouse gas emissions associated with reinforced concrete is open. However, the evaluation of CLT durability in below-grade environments, specifically concerning moisture and mould development, remains an unexplored field in research. Hence, this paper aims to analyze CLT's moisture response and mould growth risk in below-grade environments using field and laboratory experiments. A laboratory experiment was carried out to test a waterproofing membrane solution selected to compose the wall assembly in the field experiment. A large-scale experimental CLT basement was built at a cohesive soil site in Edmonton, Canada. The field experiment involved monitoring the relative humidity, temperature, and soil volumetric water content of the CLT panels, which measure 3 m by 6 m in plan and 2 m deep. Data was collected for an extended period from June 2022 to July 2023. The VVT model, developed by Hukka and Viitanen (1999) and updated by Viitanen et al., 2011 to estimate the mould growth level, was used to predict the risk of mould growth. The laboratory experiment showed that the waterproofing membrane is suitable for protection against moisture in a still-water setup. Field experiment results suggested that the primary moisture source was below the basement floor when the floor was finished inadequately. The moisture content of CLT walls was significantly increased by floor flooding and decreased by heating the basement interior. The acceptable mould index of three was surpassed during periods of abundant water below the basement floor due to flood events, showing that the CLT panels were at risk of mould growth development.

Durability evaluation and simulation of oven aged tires

Durability evaluation and simulation of oven aged tires

Prediction of durability of reinforced concrete based on hybrid-Bp neural network

Mix proportion design has a significant influence on the durability of reinforced concrete (RC). Conventional simple equations encounter challenges in effectively guiding the enhancement of durability in the design process. To address this issue, a backpropagation neural network (BPNN) model with a topological structure of 6–16–2 is devised to build a prediction model for RC durability, offering both forward design and reverse guidance for determining optimal mix proportion. Moreover, the model is optimized by the Bat Algorithm (BA), Ant Colony Optimization Algorithm (ACO), and Particle Swarm Optimization (PSO) Algorithm. The input layer parameters of the model consist the water-binder ratio and the quantity of cement, coarse aggregate, river sand (RS), fly ash (FA), slag, while the output layer parameters include the failure time for corrosion current density of reinforcement (T1) and the failure time for concrete damage degree (T2). The dataset for the model comprises 100*2 sets, which are divided into 70*2 sets for training data, 15*2 sets for validation data, and 15*2 sets for testing data. The relationship between the experimental raw materials and the durability of RC was determined through correlation analysis, and comparative analysis was conducted on the durability evaluation indices for RC. The results indicate a positive correlation between cement content and the durability of RC, whereas the content of RS, coarse aggregate, FA and slag, and water-binder ratio exhibit negative correlation with concrete durability. Among the RC groups, the A3 group demonstrated the highest performance, and the D group stood out as the optimal mineral admixture group. Utilizing the PSO-BPNN model, the following performance indices were predicted for T1: R2=0.850, MAE=38.14, MAPE=0.094, RMSE=47.218, and for T2: R2=0.872, MAE=34.541, MAPE=0.071, RMSE=42.355. Consequently, the PSO-BPNN model demonstrates the highest accuracy in predicting the correlation between concrete mix proportions and the durability of RC, thereby offering valuable guidance for the mix proportion design of RC.

Mechanical and Durability Evaluation of Latex Modified Lightweight Concrete

Modified polymer concretes are popular materials in the construction industry due to their relatively high performance, versatility and stability compared to ordinary cement concrete. In this research, by adding three different latexes, including styrene butadiene rubber, ethylene vinyl acetate and acrylic latex, the mechanical and durability properties of Light weight concrete with Leca aggregates were measured. In this regard, 15 different mixtures are carried out in two laboratory programs. in the first stage, the effect of each latex with 5, 7.5 and 10% percentages with cement are investigated, and in the next stage, the simultaneous effect of latex with Microsilica. It was measured on the properties of lightweight concrete. The results showed that the addition of latex has a significant effect on increasing the durability factors of lightweight concrete several times. With the combination of 7.5% latex and 7% Microsilica, the best compressive strength has been recorded. By using latex, the flexural strength of concrete increased around 30%. Also, the passing charge of the lightweight concrete sample without latex is 4124 coulombs, while the sample containing 10% ethylene vinyl acetate passes 451 coulombs of charge.

Process optimization of acq-polyacrylate modified bamboo aggregate and durability analysis of all-bamboo aggregate concrete

All-Bamboo Aggregate Concrete (BAC) is a type of cement concrete material where all coarse aggregates are made of bamboo aggregate, a plant material that requires necessary measures to avoid or slow down its degradation in alkaline and natural environments. This paper enhances the durability of BAC materials through the treatment of bamboo aggregate with ACQ-polyacrylate (AP method). Initially, the study explores the impact of polyacrylate dilution concentration on the compressive strength and coating thickness of BAC, and based on a reasonable modification process, conducts freeze-thaw cycles, salt solution immersion, accelerated wet-dry aging, and long-term natural environment tests to assess the durability of BAC materials. The results show that a polyacrylate solution with a dilution ratio of 1:5 can form a coating thickness of 23.8μm, performing better in various durability evaluations. After 25 freeze-thaw cycles, the BAC material's loss rate of compressive strength is lower than that of Ordinary Concrete (OC). Compared with OC, BAC materials are more susceptible to salt damage after salt solution immersion. The compressive strength loss rate under 180 days of natural environment exposure is comparable to that in 10 cycles of accelerated wet-dry aging, 28 days of salt solution immersion, and 10–15 freeze-thaw cycle tests, recommending the use of freeze-thaw cycle tests for evaluating the durability of BAC materials from an experimental efficiency perspective. By exploring the durability of BAC materials, this paper provides an innovative solution in the field of construction materials, promoting the transition of the construction industry towards sustainable development. It emphasizes the feasibility and effectiveness of improving the performance of bamboo-based materials through surface treatment technology, offering a valid reference for developing more environmentally friendly and high-performance new materials in the future.

Durability evaluation of a high-performance red mud-based composite material

The industrial solid waste red mud (RM) was served as a raw material, supplemented with high activity of high-calcium fly ash (HCFA) and low-calcium fly ash (LCFA), a red mud-based composite material (RBC) was obtained. Through the activation of a mixed solution (MS) of NaOH and water glass and the optimization of the preparation process, the prepared RBC possessed a high-performance with high strength and environmental protection. The chemical corrosion and freeze-thaw properties of the RBC were investigated by full immersion and rapid freeze-thaw methods. The strength and durability mechanisms of the RBC were explored by micro-testing techniques. The results indicated that adjusting the operated temperature of the alkaline activator can ensure paste compatibility and shorten the initial setting time. According to the integrity, economy and mechanics properties of the RBC, it is comprehensively determined that the method of wrapped steam-cured, the optimum curing time of RM-HCFA-MS and RM-LCFA-MS was 14 d and 21 d, respectively, and the corresponding compressive strength was 52.8 MPa and 58.9 MPa, respectively. When immersed in acidic, alkaline, or saline environments, the RBC consistently maintained its original structural morphology exhibiting strong corrosion resistance performance. Additionally, the maximum compressive strength was decreased by 19.5%, the maximum mass loss rate was 1.74%, and the corrosion resistance coefficients exceeded 75% after corrosion. The RBC was freeze-swelled and ruptured under repeated actions of hydrostatic and infiltration pressures, and the frost resistance ratings of RM-HCFA-MS and RM-LCFA-MS were F105 and F120, respectively. In conclusion, the RBC has good corrosion resistance and frost-thaw resistance.

Chemical durability evaluation of copper grit aggregate concrete against Alkali-Silica-Reaction, carbonation and chloride penetration

This study aims to explore the effects of varying proportions of copper grit (CG) as fine aggregate on the alkali-silica reaction (ASR), accelerated carbonation test (ACT), and rapid chloride penetration test (RCPT) of concrete. Other complementary experiments including the rate of water absorption and compressive strength of copper grit aggregate mortar (CGAM), as well as compressive strength, split tensile strength, and sorptivity test of copper grit aggregate concrete (CGAC), were conducted. The results indicate that a higher CG content, particularly at around 80% replacement in the concrete mix, enhances strength without inducing expansive ASR and mitigates carbonation and chlorination rates in concrete. Moreover, the compressive strength of CGAM increases up to a 60% replacement ratio. Water absorption decreases from 62.1 gm/cm2 for the control specimen to 47.9 gm/cm2 for mortar with 100% CG replacement. ASR test results show no significant expansion up to a 20% replacement ratio of CG, with further increases in replacement resulting in expansion below the threshold limit of 0.1%. A notable 27% increase in compressive strength is observed for 80% CG replacement at 28 days of CGAC. Additionally, carbonation depth decreases with an increase in CG quantity in CGAC mixes, with the lowest depth observed for 80% CG replacement. The carbonation coefficient remains below the threshold limit, indicating high-quality CGAC. Furthermore, the service life of CGAC was predicted and microstructural characteristics of both CGAM and CGAC were examined via Field Emissions Scanning Electron Microscopy (FESEM). The findings underscore the potential of utilizing CG as a substitute for conventional sand in mortar and concrete production, offering a promising ecological alternative for conserving natural resources and safeguarding the environment.

Static-dynamic damage mechanism and self-heating effect of a clean elastic polyurethane grouting material for trenchless rehabilitation under high stresses

Compared with traditional excavation rehabilitation, trenchless grouting rehabilitation technology has the advantages of fast, precise, and low-carbon, which has a broad application prospect in wind turbine foundation rehabilitation. In this work, a non-toxic, environment-friendly, fast-setting, high-strength, and high-toughness elastic polyurethane (PU) grouting material was proposed, and the static-dynamic damage mechanism and self-heating effect under high stress were studied by DMA, SEM, static-dynamic compression, and self-heating monitoring tests. The results show that the static compressive properties increased in a power function relationship with increasing strain rate. The dynamic compression fatigue process can be divided into adjustment stage (Stage I), viscoelastic development stage (Stage II) and failure stage (Stage III) or cyclic hardening stage (Stage III*). At 41.57 MPa and 36.95 MPa, fatigue damage parameters increased slowly in Stage I and Stage II, and sharply in Stage III. The stiffness damage, loss factor, cumulative strain, and strain rate increased by more than 100% in Stage III. Fatigue failure dominated by vertical/slanting through-cracks, shed debris, drum deformation, etc. was closely related to temperature and loading. The failure temperature about 59.1 °C, which was higher than the glass transition temperature. At 32.33 MPa, fatigue damage parameters changed slightly and then stabilized, showing exponential relationships with cycles. The max temperatures were less than 15 °C. The slight temperature rise facilitated the adjustment of structure and cyclic hardening under cyclic loading. This work can guide the further engineering application and fatigue durability evaluation of PU grouting materials.

Electronic structure control of IrO2 via conjugated polymer support for highly efficient oxygen evolution reaction

In this paper, we report synthesis of novel nanoparticle catalyst of iridium oxide supported on conjugated polymer along with evaluation of activity and durability for oxygen evolution reaction. The IrO2/poly(BIAN-thiophene)/TNT catalyst was prepared from iridium complex and poly(BIAN-thiophene)/TNT by hydrothermal method. The synthesized IrO2/poly(BIAN-thiophene)/TNT catalysts was characterized by scanning electron microscopy, transmission electron microscopy, Fourier transfer-infrared spectroscopy, x-ray photoelectron spectroscopy and electrochemical methods. The average particle size of the IrO2 particles on poly(BIAN-thiophene)/TNT was 2.5 nm. The XPS measurement revealed that Ir complex was completely converted to iridium oxide through hydrothermal treatment. The IrO2/poly(BIAN-thiophene)/TNT catalyst showed sufficient performance for OER activity and durability in acidic condition. Our results indicate that IrO2/poly(BIAN-thiophene)/TNT is one of the prospective candidate catalysts for water splitting.

Durability and Ecological Evaluation of Structural Concrete with Sewage Sludge Ash as Ternary Binder

Durability and Ecological Evaluation of Structural Concrete with Sewage Sludge Ash as Ternary Binder

Teaching trainees to implement functional communication training with multiple schedules: An evaluation of training effects and durability.

We evaluated the effects of behavioral skills training on improving participant implementation of functional communication training with multiple schedules when working with a confederate. Behavioral skills training produced mastery-level responding for all six participants who required training, providing the first empirically supported training for this functional communication training approach. Next, we assessed durability during training challenges with (a) procedural changes to the original protocol, (b) a novel confederate with different discriminative stimuli and reinforcers, and (c) relapsed confederate destructive behavior. Training effects degraded at least once for all participants and in 62% of training challenges, although continuing to expose the participant to the challenging situations or providing postsession booster training resolved the degradation in most cases. We discuss these findings in relation to their clinical implications and directions for future research.

Durability, Long-Term, and Environmental Evaluation of Alkali-Activated Alternative Soluble Silica Source for Recycled Asphalt Pavement Stabilization

Durability, Long-Term, and Environmental Evaluation of Alkali-Activated Alternative Soluble Silica Source for Recycled Asphalt Pavement Stabilization

Influence of Cow Bone Powder on Selected Engineering Properties of Lime-Stabilized Soil

This study investigates the influence of cow bone powder (CBP) on consistency and compaction characteristics of lime-stabilized soil. Twelve soil samples were collected from four routes connecting Ado-Ekiti. Index and compaction tests were performed on the natural and stabilized samples. The soil samples were classified according to AASHTO groups and eventually restructured into four (4) groups: A-6, A-7-6, A-4, and A-7-5. They were named samples A, B, C, and D respectively. The oxide compositions of the samples were determined. Lime was blended with soils at proportions of 0, 2, 4, 6, 8,10 %, and the optimal lime content (LimeOpt) was obtained. The LimeOpt + soil mixture was mixed with 2, 4, 6, 8,10 % of CBP. The Soil + LimeOpt + CBP mixtures were subjected to consistency limits and compaction tests. Plasticity index (PI) of soils A, B, C, and D was 14.19, 21.06, 11.64, and 14.19 % respectively, while the MDD was 1640, 1730, 1630, and 1631 kg/m3. Soil A, B, C, and D + LimeOpt all had reduced PIs of 7.68, 16.40, 5.04, and 12.05%, respectively. For the MDD of soil + LimeOpt mixtures, 1789, 1920, 1906, and 1898 kg/m3 were also found for Samples A, B, C, and D. Soil + LimeOpt + CBP showed that both the PI (from 0.6 to 81.7%) and MDD (from 0.1 to 14.6%) improved. On the other hand, the addition of lime to soils A, B, C, and D showed that 8% lime content offered the optimal CBR performance. Further addition of CBP to the soil + LimeOpt mixtures equally improved both the soaked and unsoaked CBR of soils A, B, C, and D predominantly with 6% CBP addition offering the peak performance. This suggests that CBP is viable and can save cost, mitigate environmental hazards, and complement lime. Strength and durability evaluation of the ternary mixture is however recommended.