Damage Test Research Articles

Erosion protection at mining sites using a concrete-enhanced synthetic turf system

Many mining sites are facing water erosion challenges due to changing weather patterns and more frequent extreme weather conditions. A concrete-reinforced engineered turf system has been developed for erosion protection and used in mining applications recently. This system consists of an impermeable geomembrane that does not allow the stormwater runoff to be in contact with the subgrade and hence, eliminating potential erosion of subgrade. This presentation provides an overview of conventional erosion protection methods and the concrete-reinforced engineered turf system, followed by an evaluation of the hydraulic performance of the concrete-reinforced engineered turf system, including the steady state overtopping flume testing, heavy debris load testing, and intentional damage testing. Case studies are provided to demonstrate installation and field performance of the erosion protection system for stormwater channels, downchutes, spillways, and slopes at mining sites.

Impact Damage Testing Study of Shanxi-Beijing Natural Gas Pipeline Based on Decision Tree Rotary Tiller Operation

Impact Damage Testing Study of Shanxi-Beijing Natural Gas Pipeline Based on Decision Tree Rotary Tiller Operation

Tensile and puncture behaviour of a woven geotextile submitted to laboratory mechanical damage tests with incinerator bottom ash

Incinerator bottom ash can be used as recycled aggregate in some engineering applications, where it may be in contact with geotextiles. In this work, a woven geotextile (made of high-density polyethylene filaments) was submitted to mechanical damage under repeated loading tests with different aggregates, namely: incinerator bottom ash, two aggregates of natural origin (tout-venant and gravel 4/8) and a synthetic aggregate (corundum). The damage suffered by the geotextile was assessed by monitoring changes on its tensile and puncture behaviour. The mechanical damage under repeated loading tests induced some reductions in the tensile and puncture properties of the geotextile. The impact of IBA was not exaggeratedly pronounced, and did not differ greatly from that of tout-venant, which was the least damaging aggregate. Gravel 4/8 had a slightly higher impact than incinerator bottom ash, with corundum being the aggregate that induced the most pronounced reductions in the tensile and puncture properties of the geotextile. The use of incinerator bottom ash as recycled aggregate in contact with geotextiles may be a viable option, promoting its valorisation and contributing to more sustainable geotechnical engineering.

Assessing and Forecasting ISR-Affected Critical Infrastructure: State-of-the-Art and Challenges.

Internal swelling reactions (ISRs) are among the most critical deterioration mechanisms affecting infrastructure's durability worldwide. While preventative measures for new structures have been extensively explored, effective protocols for diagnosing and prognosing ISR-affected structures, especially at their early stages, are still required. Therefore, through a comprehensive bibliometric analysis, this study focuses on exploring the evolution and current methods for assessing and forecasting ISR damage in concrete structures. For diagnosis, a shift from concrete petrography and non-destructive techniques (NDTs) towards more comprehensive methods (i.e., multi-level assessment) with the stiffness damage test (SDT) and damage rating index (DRI) is observed. Moreover, it identifies the valuable inputs from residual expansion and pore solution analysis as relevant parameters for prognosis. Based on these findings, a structured management framework is proposed aiming to refine the diagnosis and prognosis processes of ISR-affected infrastructure, ultimately contributing to improved long-term structural health and maintenance strategies.

Preparation and properties of a simple super‐hydrophobic carbon fiber composite surface

AbstractSuper‐hydrophobic surface is widely used in waterproof, antifouling, and anticorrosion fields because of its unique wetting characteristics. However, the rough structure of super‐hydrophobic surface is easily damaged in service, which leads to the loss of various properties, making it difficult to apply super‐hydrophobic surface on a large scale in actual production. In this paper, epoxy resin was used as adhesive, mixed with hydrophobic silica particles and sprayed on the surface of carbon fiber composites. After curing, the surface of super‐hydrophobic carbon fiber composites with contact angle of 158 ± 2° and sliding angle of 1 ± 0.5° was formed. The surface had excellent dynamic water repellent performance, and the droplets could bounce more than three times on the surface. Furthermore, the super‐hydrophobic surface had excellent wear resistance and mechanical stability. After the friction damage test, the surface structure of the sample was slightly damaged. The amount of wear was small, and the surface was still in super‐hydrophobic state. Through soaked in solutions with different pH values, the microstructure of the surface was not obviously damaged by corrosion, the contact angle of water droplets was greater than 155°. The preparation method of super‐hydrophobic surface of carbon fiber composite proposed in this study is simple and rapid, and the prepared surface has excellent performance, the practical application of super‐hydrophobic surface is promoted.

Detection mechanism of delamination in thermal barrier coatings of turbine blade using a Rayleigh wave EMAT

Nondestructive testing (NDT) for damage in thermal barrier coatings (TBCs) is significant for the safety guarantee of gas turbine blades. As a new NDT technology, electromagnetic acoustic transducer (EMAT) is widely applied for NDT of conductive structural components due to its advantages of coupling-free and high adaptability. In this paper, numerical simulations are conducted to study the wave propagation and interaction with delamination defects in TBCs inspected with a Rayleigh wave EMAT of the Lorentz force mechanism. Based on the numerical results, the wave structure in TBC, wave conversion at delamination defect, time domain EMAT signals, and its B-scan images are evaluated and the feasibility of Rayleigh wave EMAT to inspect delamination in TBCs was theoretically clarified.

Red mud application as filler in asphalt mixtures production

Red mud is the solid waste from bauxite processing during aluminium production. Its inadequate disposal causes social, economic and environmental prejudices. The industrial solid waste insertion evaluation in the production chain is beneficial and necessary. This work aims to evaluate the mechanical performance of asphalt mixtures produced with red mud as filling material. Asphalt mixtures with 5% and 7% red mud were produced, and permanent deformation and moisture-induced damage tests were carried out. A mixture without red mud addition (control) was produced for comparison. The results showed that the mixtures with red mud presented permanent deformation resistance greater than the control one, with more than 40% reduction in rutting deformation. The moisture damage did not significantly affect the mixtures tested. The red mud application as a filler in asphalt mixtures is viable and can be an alternative to reduce the damage such a waste can cause to the environment.

Evaluation of detrimental effects in concrete specimens due to the oxidation of sulfide-bearing aggregates after electrochemical treatment

Sulfide-bearing aggregates can cause significant damage when concrete has been produced without considering their potential deleterious oxidation reactivity. This study aims to find a reliable quantitative approach for assessing the impact of the harmful reaction of sulfide minerals (essentially pyrrhotite) in concrete specimens produced under laboratory conditions. To achieve this objective, different parameters such as an electrochemical treatment have been applied over 14, 28, 35 and 56-day periods on a series of concrete specimens made in the laboratory with a reactive sulfide-bearing aggregate (MSK 0.9) and non-reactive aggregate (PKA) After the treatment, the concrete specimens were tested with different tools such as non-destructive (Ultrasonic Pulse Velocity), semi destructive (expansion, modulus of elasticity and stiffness damage test) and destructive (concrete polished section and compression) methods to evaluate the impact of the deleterious reaction of the sulfide-bearing aggregates. The results show that concrete with the reactive aggregate can lose a significant amount of its mechanical performance exhibited principally by a significant reduction in modulus of elasticity (decreasing around 28% after 35 days of electrochemical treatment). Signs of damage associated with the use of the MSK aggregate were identified within concrete polished sections and under the SEM, which allowed to better describe the mechanisms of the oxidation reaction of the sulfide minerals. Ideal parameters/conditions can be achieved to evaluate the potential oxidation reaction of sulfide-bearing aggregates using the electrochemical treatment and the reduction of the modulus of elasticity of the concrete in a reasonable period of time.

The study on the influence of different damage introduction methods on the damage characteristics of aircraft composites

Composite materials have advantages incomparable to traditional metal materials. However, they are more sensitive to impact damage and their mechanical properties decrease significantly after impact damage. Therefore, it is of great significance to study the energy absorption, mechanical response and damage mechanism of materials in different ways. To study the influence of different punch diameter sizes on the material damage characteristics, three kinds of punch diameters of 12.7 mm, 16 mm and 25.4 mm are selected to carry out the quasistatic indentation test and drop hammer impact damage test on the test pieces respectively. The material damage caused by different punch sizes under two damage introduction methods is analyzed. Damage introduction was carried out on the test piece with the same layering through two methods: quasi-static indentation and drop hammer impact. The damage depth, damage area and residual strength were compared after damage introduction. The difference between quasistatic indentation and drop hammer impact damage introduction was verified by comparing the damage characteristics to each other. The results show that with the increase of punch diameter size, the damage area decreases and the residual strength of the material increases. In addition, the test results of different punch diameter sizes under the two damage introduction methods have the same change trend, which proves that the impact of punch size on the material damage characteristics has no obvious relationship with the damage introduction method. Quasi-static indentation and drop hammer impact damage have no significant difference in the residual strength of materials after damage, which verifies the equivalence of static indentation and damage introduction.

Investigating the Influence of Rigden Void of Fillers on the Moisture Damage of Asphalt Mixtures

Moisture damage and bond loss are major factors in pavement degradation, often stemming from excessive moisture accumulation due to weather events. Water infiltrates the gap between asphalt binder and aggregate, weakening the asphalt bond. Rigden Void (RV) has emerged as a crucial parameter in assessing the susceptibility of asphalt mastic-aggregate systems to moisture-induced damage. However, numerous waste natural fillers have been researched as potential aggregate filler replacements, yet their role in moisture damage remains unexplored. Therefore, this study aimed to understand how different fillers, including waste natural materials like coconut peat and bagasse, affect asphalt mixture performance and moisture damage. Results showed that Rigden Voids were positively correlated with pore size and negatively correlated with surface area. Larger pores contributed to higher Rigden Voids, while greater surface areas led to lower values. Limestone had the highest Rigden Void percentage due to its larger pore size and lower surface area. The research also explored contact parameters between fillers and asphalt, revealing varying interactions based on filler and asphalt types. Moisture damage testing demonstrated that all mixtures, both dense and porous, displayed good resistance to moisture damage. The correlation analysis between Rigden Voids and moisture damage revealed varying degrees of influence, dependent on asphalt type and aggregate gradation. Doi: 10.28991/CEJ-2023-09-12-014 Full Text: PDF

Experimental study on the damage characteristics of the stepped repaired fiber reinforced composites

Stepped repair, scarf patch repair, and patch repair are important in terms of repair techniques. The composite plate repair process starts after damage zone determination either by the unaided eye or nondestructive testing (NDT) techniques. This study investigates design cases for the stepped repairs of damaged fiber-reinforced composite materials. Before preparing steps for repair, the material around the damage zone is removed. In the stepped repair, it needs extra care to ensure that the repair plies overlap each other properly in the cut. Different cases are performed considering different step sizes. 5, 10, and 15 mm step sizes are used. The damages are given to the produced fiber-reinforced composite laminates using the Quasi-static indentation (QSI) method. Using QSI high-velocity impact simulation can be done. To get damage characteristics well-known damage test method is issued. Different span-to-punch diameter ratio (SPR) values were also used to compare different damage sizes. As a result, High ratio strength recovery was obtained using the longer step size. Maximum penetration force was reduced by nearly % 6-7 and maximum stress reduction was obtained by nearly % 8-9 for the 15 mm step size repaired composites. Among the all cases, case-1 has the highest strength recovery and case-5 has the lowest. For SPR 2, The average ultimate force value of specimens repaired with case-1 was maintained at nearly 94%. For SPR 4, repairs carried out using case-1 maintain more than 95% of damage resistance.

Phyllostachys Viridis-Leaf-like MLMN Surfaces Constructed by Nanosecond Laser Hybridization for Superhydrophobic Antifogging and Anti-Icing.

In nature, many species commonly evolve specific functional surfaces to withstand harsh external environments. In particular, structured wettability of surfaces has attracted tremendous interest due to its great potential in antifogging and anti-icing properties. Phyllostachys Viridis is a resistant low-temperature (-18 °C) plant with superhydrophobicity and ice resistivity behaviors. In this work, with inspiration from the representative cold-tolerant plants leaves, a unique multilevel micronano (MLMN) surface was fabricated on copper substrate by ultrafast laser process, which exhibited superior superhydrophobic characteristics with the water contact angle > 165° and rolling angle< 2°. In the dynamic wettability experiment, the rebound efficiency of the droplet on the MLMN surface reached 20.6%, and the contact time was only 10.6 ms. In the condensation experiment, the nucleation, growth, merging, and bouncing of fog drops on the surface was distinctly observed, indicating that rational texture structures can improve the antifogging performance of the surface. In the anti-icing experiment, the freezing time was delayed to 921 s at -10 °C, and the freezing time of salt water reached a staggering 1214 s. Moreover, the mechanical durability of MLMN surfaces was confirmed by scratch damage, sandpaper abrasion, and icing and melting cycle tests, and their repairability was evaluated for product applications in practice. Finally, the underlying antifogging/anti-icing strategy of the MLMN surface was also revealed. We anticipate that the investigations offer a promising way to handily design and fabricate multiscale hierarchical structures with reliable antifogging and anti-icing performance, especially in saltwater-related applications.

Chronic kidney disease prevalence in asymptomatic patients with risk factors—usefulness of serum cystatin C: a cross-sectional study

Abstract Background: Chronic kidney disease is recognized as a worldwide public health problem, particularly within an increasing prevalence of obesity, diabetes mellitus, and hypertension. This disease affects more than 13% of the world's population and is increasing. Further biochemical assessment with new biomarkers, such as serum cystatin C (CysC), would improve patient care and disease control. The aim of this study was to detect chronic kidney disease (CKD) in asymptomatic subjects with risk factors and evaluate CysC as early biomarker of renal damage and accurate test to estimation glomerular filtration (GF). Methods: This observational analytic and cross-sectional design included 195 patients of both sexes. A full clinical evaluation included height, weight, waist circumference, body mass index (BMI), blood pressure (BP), and family history of disease. Renal function was evaluated through serum creatinine (SCrea), serum CysC, urinary albumin, and urinary creatinine. GF was calculated using CKD-EPI creatinine (CKD-EPI Crea) and CKD-EPI creatinine-cystatin C equations (CKD-EPI Crea-CysC). Results: Renal injury showed 24% of patients with albuminuria; 18% of them were categorized as A2 and 6% as A3. Therefore, 73% had no progression risk (baseline risk), 20% moderate risk, and 7% high risk. Among analyzed groups, significant differences were found in BMI, BP, Screa, CysC, CKD-EPI Crea, and CKD-EPI Crea-CysC. Overweight population was analyzed by assessing CysC and calculating CKD-EPI Crea-CysC, showing an important change with respect to the general population. Conclusion: Combined CysC and Crea measurement provides incremental improvement in predicting measured GF.

In vitro evaluation of pro-apoptotic and anti-metastatic activity of Oliveria decumbens vent. extract, an endemic Persian medicinal plant, on HT-29 colorectal cancer cell line

Colorectal cancer is one of the most diagnosed and the third deadliest diseases worldwide. Despite early detection and screening have increased the survival rate, colorectal cancer still takes hundreds of thousands of lives each year globally. Near 50% of current chemotherapeutic drugs are indirect or direct descendants of compounds isolated from medicinal plants, which indicates plants are great potential sources of novel therapeutics. In this research, we studied the Oliveria decumbens Vent. which holds numerous secondary metabolites with pharmacological activities. However, no study on anticancer activity of this kind has been reported. The Oliveria decumbens Vent. is a rare, wild, and endemic Persian medicinal plant which is traditionally used in cases of gastrointestinal diseases and infections in Persian Traditional Medicine. Nevertheless, this is to be studied scientifically for the very first time. Consequently, this research is aimed to evaluate the anticancer effect of the flower Oliveria decumbens Vent. ethanolic extract against HT-29 colorectal cancer cell line using 6 techniques including cytotoxicity, cell viability by MTT assay, DPPH, gene expression assay, wound-healing assay (scratch-test) along with a DNA damage test. The ethanolic extract showed an Ic50 of 14.39 μg/ml. The results from real-time PCR demonstrated that the ethanolic extract from Oliveria decumbens effectively promoted apoptosis by increasing the expression of the pro-apoptotic gene, bax, and slightly decreasing the anti-apoptotic gene, bcl2. Additionally, the Scratch test indicated its potential in inhibiting metastasis, while DNA fragmentation confirmed its ability to induce DNA damage. Considering these findings, the Oliveria decumbens ethanolic extract holds promise as a prospective anticancer and chemotherapeutic agent, warranting further investigation in future studies.

A study on AAR expansion estimation of concrete pavement through SDT (Stiffness Damage Test)

A study on AAR expansion estimation of concrete pavement through SDT (Stiffness Damage Test)

Tailored enhancement of reclaimed asphalt pavement with waste engine oil/vacuum residue blend as rejuvenating agent

In recent years, there has been a noticeable increase in the production of Reclaimed Asphalt Pavement (RAP) resulting from the maintenance and rehabilitation activities conducted on asphalt pavements. However, the presence of aged binder in RAP gives rise to asphalt mixtures with unfavourable characteristics. To address this concern, the use of rejuvenating agents has been examined as a viable solution to restore the properties of aged asphalt. In this study, an investigation was undertaken to assess the efficacy of incorporating waste engine oil (WEO) and vacuum residue (VR) as hybridized rejuvenating agents for RAP. Various characteristics including penetration, softening point, ductility, viscosity, and stiffness were measured to ascertain the optimal dosage of the hybridized rejuvenating agent. Subsequently, the performance of the rejuvenated asphalt was evaluated through Marshall tests, indirect tensile strength (ITS), moisture damage, and Kim tests, comparing it with different samples. Moreover, the Creep compliance, semi-circular bending (SCB), and Cantabro loss measurements were employed in the evaluation. The findings of the study indicate that a 6.5% hybrid rejuvenator composed of WEO and VR effectively rejuvenates asphalt mixtures containing 30% RAP material by softening the aged binder. Furthermore, the rejuvenated mixture exhibited significant improvements when compared to both the virgin asphalt and RAP mixtures. In conclusion, the incorporation of WEO and VR as a hybridized rejuvenating agent showcases promising results in enhancing the performance of RAP mixtures. This, in turn, contributes to sustainable and efficient pavement practices.

Acoustic emission with machine learning in fracture of composites: preliminary study

In this paper, preliminary studies on the failure analysis of hybrid composite materials utilizing acoustic emission and machine learning are presented. The main purpose of this study was to analyze the possibilities of using machine learning techniques as a way to better cluster the data obtained from acoustic emission. In this paper, we focus on data preparation, feature extraction (Laplacian score), determination of cluster number (Caliński–Harabasz, Silhouette, and Davies–Bouldin), and testing three clustering techniques, namely K-means, fuzzy C-means, and spectral clustering. The dataset was obtained by testing fiber metal laminates—composites consisting of metal and composite layers. Two experimental tests were realized on pre-cracked rectangular specimens—one with loading in mode I and one with loading in mode II (DCB—double cantilever beam and ENF—end-notch flexural test). Elastic waves were recorded during these tests via an acoustic emission system. Preliminary studies show that the proposed method can be used successfully to cluster data obtained in this way. The obtained dataset was split into 3 clusters (for the ENF test) and 5 clusters (DCB test). In the next stages of the research campaign, based on the presented results, we intend to change the approach to semi-supervised by running additional single-cause damage tests to enhance the achieved results and enable easier damage recognition.

Enhanced laser-induced damage performance ofall-glass metasurfaces for energetic pulsed laserapplications.

To fabricate optical components with surface layers compatible with high-power laser applications that may operate as antireflective coatings, polarization rotators, or harness physical anisotropy for other uses, metasurfaces are becoming an appealing candidate. In this study, large-beam (1.05cm diameter) 351-nm laser-induced damage testing was performed on an all-glass metasurface structure composed of cone-like features with a subwavelength spacing of adjacent features. These structures were fabricated on untreated fused silica glass and damage tested, as were structures that were fabricated on fused silica glass that experienced a preliminary etching process to remove the surface Beilby layer that is characteristic of polished fused silica. The laser-induced damage onset for structures on untreated fused silica glass was 19.3J⋅c m -2, while the sample that saw an initial pretreatment etch exhibited an improved damage onset of 20.4J⋅c m -2, only 6% short of the reference pretreated glass damage onset of 21.7J⋅c m -2. For perspective, the National Ignition Facility operational average fluence at this wavelength and pulse length is about 10J/c m 2. At a fluence of 25.5J⋅c m -2, the reference (pretreated) fused silica initiated 5.2 damage sites per m m 2, while the antireflective metasurface sample with a preliminary etching process treatment initiated 9.8 damage sites per m m 2. These findings demonstrate that substrate-engraved metasurfaces are compatible with high energy and power laser applications, further broadening their application space.

Safety Evaluation of Reinforced Concrete Structures Using Multi-Source Fusion Uncertainty Cloud Inference and Experimental Study.

Structural damage detection and safety evaluations have emerged as a core driving force in structural health monitoring (SHM). Focusing on the multi-source monitoring data in sensing systems and the uncertainty caused by initial defects and monitoring errors, in this study, we develop a comprehensive method for evaluating structural safety, named multi-source fusion uncertainty cloud inference (MFUCI), that focuses on characterizing the relationship between condition indexes and structural performance in order to quantify the structural health status. Firstly, based on cloud theory, the cloud numerical characteristics of the condition index cloud drops are used to establish the qualitative rule base. Next, the proposed multi-source fusion generator yields a multi-source joint certainty degree, which is then transformed into cloud drops with certainty degree information. Lastly, a quantitative structural health evaluation is performed through precision processing. This study focuses on the numerical simulation of an RC frame at the structural level and an RC T-beam damage test at the component level, based on the stiffness degradation process. The results show that the proposed method is effective at evaluating the health of components and structures in a quantitative manner. It demonstrates reliability and robustness by incorporating uncertainty information through noise immunity and cross-domain inference, outperforming baseline models such as Bayesian neural network (BNN) in uncertainty estimations and LSTM in point estimations.

A mitigation strategy for productivity impairment in sandstone reservoirs with varying clay mineralogy

The interaction between drilling fluids and oil and gas reservoir formations can result in the reduction or blockage of the micropore structural network, leading to a consequent decrease in permeability. Due to the negative economic impact of formation damage on hydrocarbon production, formulating drilling fluids with characteristics that minimise formation damage has been a major focus of the petroleum industry and researchers since the 1970s–1980s. Formation damage can significantly affect the ultimate productivity in hydrocarbon-bearing formations, especially in sandstone reservoirs with varying clay mineralogy such as kaolinite, smectite, illite, and mixed layer (illite + smectite) clay mineralogy in the micropore structural networks. These clay minerals are highly unstable/reactive and often appear as pore lining, pore bridging, and pore-filling along the walls of the micropore structural, inevitably coming into contact with drilling fluids (both solids and filtrates) that have invaded the micropore structure. Existing studies on the understanding of the relationship between drilling fluid formulation and formation damage mechanisms have not adequately addressed the role of individual species of clay minerals and their varying physicochemical properties during the formulation of drilling fluids for sandstone reservoirs with varying clay minerals. Instead, clay minerals are often treated as a whole or a single group. The work presented in this paper aims to examine and quantifies the impact of three drilling fluids (PAC-UL water-based, potassium formate, and halide drilling fluids) on productivity impairment in kaolinitic sandstone reservoirs and in kaolinitic and mixed-layer (illitic + smectitic) sandstone reservoirs. To achieve this, a high-temperature, high-pressure (HTHP) formation damage testing facility was designed and built to determine the initial and return permeability of selected hydrocarbon reservoirs using core samples. The formation damage mechanisms resulting from the interaction of the reservoir rocks with different formulations of drilling fluids are fully characterized using a combination of scanning electron microscopy, energy dispersive X-ray and micro-computed tomography. For all three drilling fluid formulations, the results showed an enhanced return permeability of the kaolinitic sandstone after interaction with the specially formulated halide drilling fluid.