Durability Characterization Research Articles

Strength and Durability Characterization of Structural Concrete Made of Recycled Plastic.

This study investigates the feasibility of utilizing recycled plastic waste as a partial substitute for sand in concrete production. Reprocessing used plastic items or materials involves collecting, cleaning, shredding, and melting, resulting in reprocessed plastic particles. Incorporating these recycled plastic particles into concrete addresses environmental concerns related to plastic disposal and the growing scarcity and increasing cost of natural sand. To evaluate the sand replacement capacity of recycled plastic, four types of mixtures were created with varying levels of recycled plastic replacement (5%, 10%, 15%, and 20%). All mixtures maintained a water-to-binding ratio of 0.55 and were tested at 7, 28, and 56 days. The testing regimen encompassed determining the slump value, density, compressive strength, tensile strength, and resistance to freezing and thawing. The findings revealed that replacing sand in the concrete mix with recycled plastic enhanced workability, which was attributed to the hydrophobic nature of the plastic particles. However, both compressive and tensile strength exhibited a declining trend. Additionally, after undergoing multiple freezing and thawing cycles, the concrete mix exhibited poor durability properties and brittleness. These issues may arise due to factors such as incompatibility, non-uniformity, reduced cohesion, and the lower density of plastic particles.

Dynamic and Durability Characterization Of Silty-Sand Mixture Treated with Cement and Mineral Polymer

Dynamic and Durability Characterization Of Silty-Sand Mixture Treated with Cement and Mineral Polymer

Mechanical and Durability Characterization of Hybrid Recycled Aggregate Concrete.

The recycling of construction and demolition waste (CDW) for the extraction of recycled concrete aggregates (RCAs) to be used to produce recycled aggregate concrete (RAC) is widely acknowledged internationally. However, CDW not only contains concrete debris but may also contain burnt clay bricks. The recycling of such CDW without the segregation of different components would result in recycled aggregates having different proportions of concrete and brick aggregates. The utilization of these aggregates in concrete requires a detailed investigation of their mechanical and durability properties. In this regard, the present study focused on investigating the mechanical and durability properties of hybrid recycled aggregate concrete (HRAC) made by the 100% replacing of natural aggregates with recycled brick (RBAs) and RCA in hybrid form. The partial replacement of cement with fly ash was also considered to reduce the corban footprint of concrete. An extensive experimental program was designed and carried out in two phases. In the first phase, a total of 48 concrete mixes containing coarse RBA and RCA in mono and hybrid forms were prepared and tested for their compressive strength. The test results indicated that the compressive strength of HRAC is greatly affected by the proportion of coarse RBA and RCA. In the second phase, based on the results of the first phase, eight concrete mixes with the most critical proportions of RBA and RCA in hybrid form were selected to evaluate their mechanical and durability performance. In addition, four mixes with natural aggregates were also prepared for comparison purposes. To evaluate the mechanical properties of the concrete mixes, compressive strength and modulus of rupture (MOR) tests were performed, while for the evaluation of durability properties, water absorption and behavior after exposure to aggressive conditions of acidic and brine solutions were studied. The results revealed that a 20% replacement of cement with fly ash resulted in acceptable mechanical and durability properties of HRAC intended to be used for making concrete bricks or pavers.

Physical-chemical, mechanical and durability characterization of historical adobe buildings from the State of Michoacan, Mexico

Most earthen historical buildings have been abandoned for decades, exposed to the weathering and the passage of time. In Mexico, the low status of earthen constructions has increased these deterioration processes, resulting into the risk of disappearance of this significant architectural heritage. Historical adobes from monumental buildings in the State of Michoacan were sampled and collected in the localities of La Huacana (H) and Santa Cruz de Morelos (SC). The specimens were characterized in the materials laboratory, assessing their physical-chemical, mechanical and durability properties. An interdisciplinary methodology was designed through institutional cooperation and the application of different test methods.The adobes showed totally different compositions and proportions, and stabilizers like vegetal fibers, nevertheless, the mechanical performance of both samples was very similar, achieving respectable values in the context of historical adobe structures. Several correlations were found through the analyses: the physical properties like the density, the color or the electrical resistivity were related with the mechanical and durability ones; the non-destructive testing (NDT) allowed to calculate the dynamic elasticity modulus and infer the mechanical behavior; the chemical characterization enabled to obtain the elemental and mineralogical composition; and the Atterberg limits gave the soil classification.The research showed the broad diversity of earthen solutions and demonstrated how the granulometry is not a limitation to the adobe production, since the local soils can achieve similar mechanical and durability behaviors. Furthermore, H presented very different composition than the guidelines for earthen construction; nevertheless, the samples showed better durability performance and lower capillarity absorption rates. It is hoped that the results obtained with this research can help the further development of the earthen materials characterization and the decision-making process for the restoration and conservation of historical and vernacular constructions.

Duramesh registry study: short-term outcomes using mesh suture for abdominal wall closure.

Sutures are flexible linear elements that join tissue and maintain their hold with a surgeon-created knot. Tension at the suture/tissue interface can cut the very tissues that sutures are designed to hold, leading to dehiscence and incisional hernia formation. A new suture design (Duramesh, Mesh Suture Inc., Chicago, IL) was approved for marketing by the United States Food and Drug Administration in September 2022. The multiple filaments of the mesh suture are designed to diffuse tension at the suture/tissue interface thereby limiting pull-through. The macroporosity and hollow core of the mesh suture encourage fibrovascular incorporation for a durable repair. We created the first registry and clinical report of patients undergoing mesh suture implantation to assess its real-world effectiveness. A patient registry was created based on institutional implant logs from January to August 2023 at an integrated health-care system. Operative reports were reviewed by the study team to verify use of "Duramesh" by dictation. Retrospective chart review was conducted to evaluate patient and surgical characteristics, follow-up, and short-term outcomes of interest. Results were analyzed using descriptive statistics and Chi-squared analysis with Microsoft Excel and GraphPad Prism. Three hundred seventy-nine separate implantations by 56 surgeons across 12 (sub) specialties at a university hospital and two community hospitals were performed. Mesh suture was used for treatment of the abdominal wall in 314 cases. Follow-up averaged 80.8 ± 52.4 days. The most common abdominal wall indications were ventral hernia repair (N = 97), fascial closure (N = 93), abdominal donor site closure from autologous breast reconstruction (N = 51), and umbilical hernia repair (N = 41). Mesh suture was used in all Centers for Disease Control (CDC) wound classifications, including 92 CDC class 2 or 3 abdominal operations. There were 19 surgical site infections (6.1%) and 37 surgical site events (11.8%). Short-term registry data demonstrates the wide diversity of surgical disciplines and scenarios in which mesh suture has been used to date. The early adoption of mesh suture into practice highlights that consequences of suture pull-through influence operative decision making. As this is the first interim report of the Duramesh mesh suture registry, follow-up is too short for characterization of long-term durability of abdominal wall closures.

Mechanical and durability characterization study on partial replacement of coconut shell in geopolymer concrete

Mechanical and durability characterization study on partial replacement of coconut shell in geopolymer concrete

Computational model to estimate chloride diffusivity by ternary random walk simulation on tomographic 3D microstructure of cement matrix

This study proposed a model to estimate the chloride diffusivity of the cement matrix by performing a ternary random walk simulation, which considers both connected and disconnected pores in tomographic 3D microstructure. Ternary structures of cement paste, consisting of pore, hydrate, and anhydrous phases, were obtained from X-ray micro-CT images by calculating each phase's representative linear attenuation coefficient based on the quantitative X-ray diffraction results. A novel random walk simulation introducing the concept of hydrate retention time upon ternary microstructures was applied to cement paste. From the developed ternary random walk simulation, the values of the hydrate retention time were determined considering multi-scale porosities and the experimental data of chloride diffusivity. The results showed that the hydrate retention time ranged from 325 to 108 as w/c increased from 0.3 to 0.7. Empirical formulas for estimating hydrate retention time according to the porosity of hydrate voxels and the hydration degree was established. Based on these formulas, the proposed model performing ternary random walk simulation on X-ray micro-CT images enables the estimation of chloride diffusivity of actual cement paste with only the initial w/c as input, making it a practical and accurate tool for durability characterization.

Polymerization of Physisorbed Molecular Monolayers via Overhanging Alkynyl Chains: Characterization of Polymerization Kinetics and Monolayer Durability

Polymerization of Physisorbed Molecular Monolayers via Overhanging Alkynyl Chains: Characterization of Polymerization Kinetics and Monolayer Durability

Nickel plating on wood and wood composite surfaces: Characterization of surface durability

In this study, the performance of nickel plating on wooden surfaces was investigated. Black pine (BP), medium density fiber board (MDF) and particle board (PB) were used for the wooden samples. After the sample surfaces were sanded with 200, 500 and 1000 grit sandpaper and varnished with polyurethane varnish (150 g/m2), they were nickel plated using a spray gun and compressed air. After drying the samples at room temperature for 72 h, scratch analyses were performed according to TS EN 15186 (2012) and TS EN ISO 2409 (2020) and abrasion analyses were performed according to TS EN 13329 +A. The staining resistance of the samples was determined according to the DIN 53799 standard. According to the results, surface strength of the MDF samples was lower than those of PB and BP. The scratch analysis results for the black nickel coating were lower than those for TS EN 15186 (2012). However, it was higher according to TS EN ISO 2409 (2020) scratch analysis. In terms of stain resistance, all samples were found to be resistant to water, soap, tea, and acetone stains, except for coffee stains. Upon visual examination, a slight coffee stain was observed on the sample surfaces. As a result, in the light of surface strength analysis, it was concluded that the surfaces of wooden boards are not suitable for nickel plating.

Physico-Mechanical and Durability Characterization of Eco-Ternary Cementitious Binder Containing Calcined Clay/Rice Husk Ash and Recycled Glass Powder.

The objective of this study is to determine the influence of recycled glass powder (GP) on the physico-mechanical behavior and durability of a ternary cementitious binder containing calcined clay_metakaolin (MK) or rice husk ash (RHA). Different mortars were produced and characterized in fresh and hardened states. Reference mortars were produced using 100% cement CEM II/B-L 42.5R and 70% CEM + 30% MK or RHA. Test mortars were produced with the substitution of the MK or RHA with the GP and keeping the rate of the substitution at 30%; i.e., in ratios of 20:10, 15:15, and 20:10 of MK/RHA:GP. The water/binder weight ratio was maintained at 0.5, and the consistency of all mortars was adjusted using an admixture (superplasticizer/binder weight ratio of 0.75%). The substitution of MK and RHA with GP reduces the water demand to achieve the normal consistency of pastes and therefore increases the workability of mortars containing both binders CEM+MK+GP and CEM+RHA+GP. The substitution of MK and RHA with GP slightly reduces the compressive strength for both binders. The water-accessible porosity slightly increases for the substitution of MK and reduces for the substitution of RHA with GP. The mass losses after acid attack slightly increase with the substitution with GP, lower for the MK than the RHA up to 15% GP, but it remained far below that of 100% CEM. The results show that the substitution of MK and RHA with GP can improve the physical properties and durability of the mortars compared with that of 100% CEM, but it slightly decreases the mechanical properties due to the low rate of the pozzolanic reactivity of the GP. Further studies should seek to understand the reactivity behavior of the GP at the microstructure scale and therefore improve the mechanical performance of GP based mortar.

Characterization of durability and reconnection patterns at time of repeat ablation after single-shot pulsed field pulmonary vein isolation

BackgroundPulsed field ablation (PFA) is a novel method of cardiac ablation where there is insufficient knowledge on the durability and reconnection patterns after pulmonary vein isolation (PVI). The aim of this study was to characterize the electrophysiological findings at time of repeat procedure in real-world atrial fibrillation (AF) patients.MethodsPatients who underwent a repeat procedure (n=26) for symptomatic recurrent arrhythmias after index first-time treatment with single-shot PFA PVI (n=266) from July 2021 to June 2023 were investigated with 3D high-density mapping and ad-hoc re-ablation by radiofrequency or focal PFA.ResultsIndex indication for PVI was persistent AF in 17 (65%) patients. The mean time to repeat procedure was 292 ± 119 days. Of the 26 patients (104 veins), complete durable PVI was observed in 11/26 (42%) with a durable vein isolation rate of 72/104 (69%). Two patients (8%) had all four veins reconnected. The posterior wall was durably isolated in 4/5 (80%) of the cases. The predominant arrhythmia mechanism was AF in 17/26 (65%) patients and regular atrial tachycardia (AT) in 9/26 (35%). Reconnection was observed 9/26 (35%) in right superior, 11/26 (42%) in right inferior, 7/26 (27%) in left superior, 5/26 (19%) in left inferior, p=0.31 between veins. The gaps were significantly clustered in the right-sided anterior carina compared to other regions (P=0.009).ConclusionsDurable PVI was observed in less than half of the patients at time of repeat procedure. No significant difference in PV reconnection pattern was observed, but the gap location was preferentially located at the anterior aspects of the right-sided PVs. Predominant recurrence was AF. More data is needed to establish lesion formation and durability and AT circuits after PFA.

Physico-mechanical and durability characterization of earthen plaster stabilized with fermented rice husk for coating adobe walls

Physico-mechanical and durability characterization of earthen plaster stabilized with fermented rice husk for coating adobe walls

Durability characterization of landslide material from mudrock of Jatiluhur formation

The infrastructure project has many lies on the mudrock foundation. Some reports in Hambalang, West Java, Indonesia, state the engineering problem related to landslides and foundation failure due to mudrock material's existence. The mudrock originated from Jatiluhur Formation. The problem is also present in slope stability, such as surface erosion and landslide on the many slopes. Landslide material from mudrock material has easily broken into smaller fragments. This research used the wet-dry cycle to evaluate mudrock's durability to weathering on a laboratory scale. The preparation of the test samples in the form of intact rock with a weight of 450-550 grams and then open exposure under sun dry was conducted. The sample was then immersed in water for 24 hours. ISRM physical properties were conducted and correlated with statistical analyses to determine factors affecting the mudrock's durability. From the index of durability, mudrock in Jatiluhur Formation in this research area had various degrees of disintegration. The siltstone samples remained intact until the 15<sup>th</sup> cycle, unlike shale and claystone samples had expressed low durability and rapid disintegration rate. A series of investigation durability characteristics of mudrock in this study can be applied to other samples and formations that are quantitively and qualitatively.

Characterization of biaxial fatigue durability for fuel cell membranes using pressure-loaded blisters

In this study, a customized pressure-loaded blister test device capable of achieving sinusoidal control of pressure was developed to investigate the biaxial fatigue durability of proton exchange membrane (PEM) for fuel cells. The effect of temperature, relative humidity and stress state on biaxial fatigue life was investigated, and the biaxial stress-strain curves under different temperature and relative humidity conditions were also compared. It is found that increasing pressure induces higher biaxial stress and exacerbates the accumulation of plastic strain in the membrane, which adversely affects biaxial fatigue lifetime of PEM. Increasing temperature and decreasing humidity reduces the biaxial yield strength, thereby reducing the fatigue life of membrane. In addition, lowering temperature can lead to a transition in the failure mode from complete rupture to leakage failure. The increase in air pressure ratio, Rp, (minimum to maximum pressure ratio) also leads to premature membrane failure.

Mathematical characterization of performance and durability for the WO3 – Nb2O5 electrochromic thin films using finite experimental data

A comparison is made among the peak current density values of 1000 cycles of experimental chronoamperometry for WO3-Nb2O5 films with the simulated values. Quadratic and linear regression models are developed by using MATLAB standard function ‘fitlm’ to get least MSE and ‘predict’ method to extrapolate the current density values. Initial 400, 500, and 600 experimental cycles are used as starting references for predictions. Predicted model having −0.09 percent change with the experimental curve is followed to predict 10,000 cyclic values with −4.73 % difference. Binding energy values for W6+ (35.9, 38.05 eV), W5+ (36.8, 34.65 eV) and Nb5+ (210.35, 207.55 eV) are measured.

Mix design, mechanical properties and durability of the rubberized geopolymer concrete: A review

Rubberized geopolymer concrete (RGPC) is an innovative, user and environmentally friendly invention in building materials that require less energy to manufacture and have a lower carbon footprint than cement-based systems, alleviating global warming concerns. It has the potential of reducing the dilemma of disposal of the huge rubber tire wastes by including them in production as a partial substitute for natural fine aggregate. This hereby avoids the depletion of natural mineral aggregates and protects against air, water and soil pollution. The current review shows the feasibility of incorporating waste rubber fibers in geopolymer concrete (GPC), which emits 90% less carbon dioxide when compared with ordinary Portland cement (OPC), to address the issues mentioned above. To the author's knowledge, no comprehensive studies have reviewed the properties, durability, mechanical, mix design and carbon footprint, of RGPC. For strength characterization, this review work analyzed the flexural, split tensile, and compressive strengths of RGPC. To review the durability characterization of RGPC, water absorption, acid resistance, chloride diffusion, sulfate resistance, and water permeability were evaluated. Finally, the outcome of this review concludes that RGPC has distinct, tangible benefits compared with OPC concrete regarding environment protection, durability, and strength properties. Furthermore, RGPC is recommended for producing lightweight concrete and civil engineering structures when compressive strength is not the main property.

Newly developed cement–ground granite scraps composite for solidification/stabilization of radioactive wastes: characterization and evaluation of the mechanical durability

The core objective of the present study is to develop an added value cement–granite composite (CGC) based on granite (G) scraps and Ordinary Portland Cement (OPC). The granite scraps were collected, washed, ground, sieved, and the finest powder was used as an inorganic admixture for developing the CGC. Plain water was added to the granite–cement powder and thoroughly mixed. The obtained pastes were casted for 28 days prior to their physical, structural, thermal characterizations and their mechanical evaluation. Factors assumed, mostly, to affect the final properties of the CGC blocks, e.g. granite/cement and water: cement ratios were studied. The reached monolith cement–granite composite has many advantages, e.g. lower density, very low water absorption percentage, acceptable compressive strength values and significant radiation and thermal stability. Based on the experimental data reached it could be stated that: for its economical advantages, where the one of its basic components is a waste. In addition to the acceptable mechanical traits of the developed composite, it can be candidate properly as an inert matrix for some radioactive wastes containment, for application in many field including: construction sector (interior and exterior of household walls, floor tiles, etc.), and for many others. The environmental reward due to management the accumulated problematic solid granite scraps is, certainly, a gain.

Crosslinking inert liquidlike polydimethylsiloxane brushes using bis-diazirine chemical insertion for enhanced mechanical durability

Inert polymer brushes offer excellent omniphobic and antifouling properties but enhancing their durability remains a challenge, since their chemical inertness also means they lack the functionality necessary for traditional crosslinking reactions. We report the crosslinking of nanoscale polydimethylsiloxane (PDMS) brushes on surfaces through a chemically non-destructive C–H insertion. bis-Diazirine crosslinkers are employed to covalently link methyl groups (i.e., insertion into Si–C–H bonds) along neighboring PDMS chains upon thermal activation. The successful crosslinking of PDMS brushes is evidenced directly by X-ray photoelectron spectroscopy analysis and indirectly through mechanical durability characterization using Martindale abrasion. The apparent contact angles and low contact angle hysteresis of crosslinked PDMS brushes are well-maintained post abrasion, indicating enhanced mechanical durability as compared to uncrosslinked brushes. The longevity of the liquidlike character of crosslinked PDMS brushes is also improved following mechanical wear, with a shear ice adhesion strength half that of uncrosslinked brush surfaces. The crosslinked surfaces are also resistant to acid corrosion, heating, sonication, and tape peeling, indicating that the physicochemical stability of PDMS brushes is not degraded upon crosslinking. Finally, crosslinked brushes are additionally deposited on polycarbonate substrates, and the optical transparency, enhanced durability, and droplet shedding capability of the coated substrates are demonstrated. Overall, this study provides a new pathway for the design of durable inert nanoscale coatings that maintain their attractive surface properties after mechanical wear.

AE Monitoring of Damage in Flexible Solar Cells under Biaxial Loading

Microdamage initiation and accumulation processes in flexible solar cells under biaxial tensile loading were monitored by acoustic emission (AE) technique. Furthermore, the contribution to the degradation of power generation performance was evaluated using lock-in thermography (LT). Comparing the results of uniaxial with biaxial tensile tests, it was shown that the strains at the onset of the degradation in the maximum power Pmax and the short circuit current Isc were equivalent for both tests. Whereas the open circuit voltage Voc decreased at lower strain in the biaxial test than the uniaxial. Furthermore, it was also observed that the cracks near the current collection holes were perpendicular to the tensile direction in the uniaxial, whereas in the biaxial, the cracks were radial from the current collection holes. Consequently, the fundamental knowledge on the characterization of durability of flexible solar cells, such as the prediction of degradation was obtained.

Durability assessment of the oldest concrete structure in the Mediterranean coastline: The Ghazaouet harbour

The present article deals with the condition assessment and durability characterization of the oldest Algerian concrete structures exposed to the Mediterranean sea for around 100 years, taking as a study case the port of Ghazaouet, located in the extreme northwest of Algeria (province of Tlemcen). This study includes inspections of the condition of the harbour structures and in-situ tests conducted in atmospheric zone to characterise the mechanical characteristics of concrete (sclerometer rebound), and durability indicators determination as porosity (Mercury Intrusion Porosimetry) and chloride diffusion coefficient calculated with total and free chloride profiles.Diagnosis inspections on the port's concrete structures indicate localized damage with acceptable mechanical resistance. However, an increase in porosity with microstructure change was noted and extensive chloride penetration have been recorded. Finally, simulation analysis of the valuable data of diffusion coefficient (Da) and surface concentration (Cs), showed the great effect of the chlorides concentration at the surface on long-term exposure of concrete behaviour in seawater.