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Soil shrinkage leads to cracking of expansive soil during desiccation. Prevention of crack propagation in soil is of paramount importance. This research examines the effect of auxetic yarns, in control of expansive soil desiccation cracks. In this study, auxetic yarns with optimal properties were produced. Using an innovative test method, the influence of auxetic yarn structure on the prevention of soil crack propagation was investigated. It was found that the inclusion of auxetic yarns in the expansive soil results in a 9.94% reduction in crack propagation of the soil. In order to confirm the positive effect of auxetic yarns on the behavior of the soil samples, pull-out test was conducted on the auxetic yarns incorporated in the soil samples. The interaction between the soil and the auxetic yarn was found to be much higher than the interaction between the equivalent non-auxetic yarn and the same soil. This was not only attributed to the transverse expansion of auxetic yarn, but also to the helical structure that occurs in such yarn during the pull-out. The auxetic effect of the yarn results in a 27.3% increase in the force needed to pull the yarn from the soil matrix. [ABSTRACT FROM AUTHOR]

This paper presents the pull-out bonding behaviour and mechanical performance of recycled carbon fibre (rCF) reinforced concrete based on the recent investigation of fibre reinforced concrete (FRC) with rCF recovered from pyrolysis. Single fibre pull-out tests have been carried out to identify the apparent interfacial shear strength of different types of rCF and virgin carbon fibre (vCF) to identify the fibre matrix connection. Furthermore, a series of tests have been carried out to identify the workability, compressive strength and tensile strength of FRC. Besides rCF, also vCF and steel fibre were used for fabrication of FRC test specimens. rCF have shown the same adhesion behaviour and strength like vCF. Furthermore, the use of unsized or acrylate-based sized rCF creates an adhesion between fibre and matrix material. During the pull-out tests, the failure does not occur as an adhesive crack between fibre and cement matrix, but as a cohesive crack in the cement matrix. The mechanical performance of FRC with rCF was compared with mortar and FRC with vCF and steel fibres. The results of compressive test conducted for FRC with vCF and rCF indicated that the influence of vCF and rCF on the compressive strength of FRC was insignificant. On the other hand, the results of tensile test conducted for FRC with vCF and rCF indicated that the tensile strength of FRC with rCF was at least 14.9% greater than that of FRC with vCF. [ABSTRACT FROM AUTHOR]

In this paper, the bond‐slip behavior and bond‐slip constitutive model of corroded reinforcement embedded in polypropylene fiber‐reinforced concrete (PFRC) were investigated. The central pullout test was conducted for 36 specimens. The effects of the corrosion level of reinforcement and the volume fraction of polypropylene (PP) fibers in concrete on the damage mode and bond‐slip process between reinforcement and concrete were studied. Based on the experimental data, a modified bond‐slip constitutive model considering the corrosion level of reinforcement and the volume fraction of PP fibers in concrete was proposed, and the proposed modified bond‐slip constitutive model was used in finite element analysis. The results showed that the addition of PP fibers effectively improved the ultimate bond strength, peak slip and bond toughness of reinforcement and concrete. The enhancement of the bonding properties of the specimens by the PP fibers remained significant after the reinforcement was corroded. The proposed modified bond‐slip constitutive model agreed well with the experimental results. The validity of the proposed model was further verified by finite element analysis. [ABSTRACT FROM AUTHOR]

Copyright of Iraqi Journal of Laser is the property of Republic of Iraq Ministry of Higher Education & Scientific Research (MOHESR) and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

Geopolymers and antacid-enacted fasteners have accumulated critical interest as promising development and fixing materials because of their exceptional properties. Also, they bring about less contamination contrasted with regular concrete cements. Geopolymers address a clever class of suggested restricting materials blended through the basic enactment of bountiful aluminosilicate materials. The usage of geopolymer materials from side effects offers a critical decrease in carbon impression and yields positive natural effects. Geopolymer is progressively recognized as a plausible substitute for OPC concrete. In this review, sodium-based antacid activators, especially sodium metasilicate (Na2SiO3), were used for different blend extents. The boundaries researched included NaOH arrangements with a grouping of 8 M, alongside a Na2SiO3/NaOH proportion of 1. This paper evaluates the fundamental characteristics of geopolymer cement beams, employing red mud and GGBFS in powdered form as complete replacements for traditional concrete. Six bar specimens are tested under a two-point static loading condition, all cured at room temperature under ambient conditions. Of the six beams, three were exposed to flexural conduct testing with a molarity of 8 M, while the excess three beams were tried for shear conduct. The outcomes of testing geopolymer beams subjected to shear and bending loads indicated that the beams incorporating aluminum slag performed better than those incorporating blast furnace slag. Both types also demonstrated promising results compared to beams incorporating OPC, highlighting their potential environmental benefits compared to cement use. [ABSTRACT FROM AUTHOR]

Copyright of Bulletin of the Chinese Ceramic Society is the property of Bulletin of the Chinese Ceramic Society Editorial Office and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

Synthetic bone models such as polyurethane (PU) foam are a well-established substitute to cadaveric bone for screw pull-out testing; however, little attention has been given to the effect of PU foam anisotropy on orthopaedic implant testing. Compressive and screw pull-out performance in three PU foam densities; 0.16 g/cm3 (PCF 10), 0.32 g/cm3 (PCF 20) and 0.64 g/cm3 (PCF 40) were performed in each of the X, Y or Z orientations. The maximum compressive force, stiffness in the linear region, maximum stress and modulus were determined for all compression tests. Pedicle screws were inserted and pulled out axially to determine maximum pull-out force, energy to failure and stiffness. One-way ANOVA and post hoc tests were used to compare outcome variables between PU foam densities and orientations, respectively. Compression tests demonstrated the maximum force was significantly different between all orientations for PCF 20 (X, Y and Z) while stiffness and maximum stress were different between X versus Y and X versus Z. Maximum pull-out force was significantly different between all orientations for PCF 10 foam. No significant differences were noted for other foam densities. There is potential for screw pull-out testing results to be significantly affected by orientation in lower density PU foams. It is recommended that a single, known orientation of the PU foam block be used for experimental testing. [ABSTRACT FROM AUTHOR]

Introducción: la avulsión de la espina tibial posterior en el adulto representa una forma infrecuente de compromiso del ligamento cruzado posterior (LCP), más común de ver en la población pediátrica. La posibilidad de consolidación de esta lesión, con el tratamiento adecuado en forma temprana, depende de un diagnóstico precoz. Caso: reportamos el caso de una paciente de veintisiete años con una lesión multiligamentaria de rodilla con inestabilidad medial y posterior, por trauma de alta energía tras sufrir un accidente de tránsito en moto. Fue tratada mediante una fijación abierta con técnica de “pull-out”. Discusión: en países asiáticos es una lesión frecuente por la alta prevalencia de accidentes en moto, pero menos común en nuestro medio. Si bien el manejo quirúrgico temprano muestra mejores resultados, no existe consenso actual en cuanto a la técnica. Dos tipos de resolución (abierta y artroscópica) muestran resultados similares a largo plazo, con un mayor porcentaje de artrofibrosis en el último grupo. Conclusión: al existir controversia sobre su manejo quirúrgico, creemos que la combinación de las ventajas de ambas técnicas (abierta y artroscópica) constituye una opción reproducible, de bajo costo y con bajo índice de complicaciones.

A procedure and results of estimating the adhesion strength of a fiber–matrix system are presented. Carbon and basalt fibers are used, and a composition of epoxy resin and an amine solidifier is applied as a polymer matrix. The results of strength tests on the estimation of the adhesion strength by the pull-out method using two types of samples are presented: macro- and microsamples differ in the accuracy of determining the contact area between a fiber and the polymer matrix. The values of adhesion strength of microsamples based on elemental fibers are found to be lower than those of macrosamples, but the determination accuracy is substantially higher than that for the macrosamples. [ABSTRACT FROM AUTHOR]

The purpose of the present study was to investigate differences in a 100 m breaststroke time-trial between elite and sub-elite swimmers. Elite and sub-elite male swimmers (seven each; 772.1 ± 35.2 and 610.6 ± 24.7 FINA point, respectively) performed 100 m breaststroke, which was recorded by a multi-camera system that provided the mean and time-series velocity data in the glide, pull-out, and clean-swimming segments. The mean velocity in each segment was compared between the groups using an independent-samples t-test (for the 1st lap) and two-way mixed-design ANOVA (for the 2nd—4th laps), which suggested a larger mean clean-swimming (in all laps; 7–11% difference) and glide (in the 2nd and 3rd lap; about 13% difference) velocity for the elite swimmers. The time-series data displayed faster velocity in elite swimmers than in the sub-elite group during the first part (up to 40% time) of the glide segment (p < 0.05). Differences in the clean-swimming segment between the groups were observed (p < 0.001) apart from the first 5–15% time of the segment. No differences in the pull-out and at the beginning of the clean-swimming imply that coaches and swimmers should not assume that a good clean-swimming technique also guarantees fast velocity in these segments. [ABSTRACT FROM AUTHOR]

Cobalt–chromium alloys are often employed in those environments that require reliable wear and friction properties. Cold Gas Dynamic Spray offers the opportunity to obtain good quality deposits of Stellite-6, that can be successfully used in harsh environments, where good surface performance, in terms of wear resistance, is required. It is also well-known that Stellite-6 is subjected to several physical changes at the interface during dry sliding, that are often related to the loading conditions. As a consequence, wear behavior of this alloy can undergo some variations that linear models are not able to capture, since micro-structural modifications occur during operation. To better understand the wear mechanisms of cold-sprayed Stellite-6 coatings together with the occurring physical phenomena, a systematic experimental study was performed, in fact, to date, no such in-depth tribological studies have been performed. Tests were conducted under combinations of two sliding speeds (0.1 and 0.5 m/s) and four contact pressure in the range of 2-5 MPa. In low-speed tests, abrasive wear is evident, where detachment and pull-out phenomena mainly affect the worn surface of coatings. On the other hand, subsurface cracking was observed in high-speed tests, as well as evidence of plastic deformation on the wear surface. These results suggest that observed wear mechanisms are more likely a consequence of adhesive wear. Unique to this study, the cross-sectional nano-indentation tests showed how the stiffness of the coating, near to wear interface, increases significantly in the case of the lowest value of sliding speed (i.e., v = 0.1 m/s), whereas tends to decrease at high speeds, i.e., v = 0.5 m/s, as a consequence of the formation of subsurface cracks into the coating. [ABSTRACT FROM AUTHOR]

Purpose: To evaluate the retention force of a novel conometric system after thermomechanical aging. In addition, the conometric system's retention force was compared with that of the cemented implant‐retained crowns. Materials and methods: Two systems to retain implant crowns were tested in this study: a conometric system and a cement‐retained system. Forty‐eight zirconia crowns were fabricated using computer‐aided design and computer‐aided manufacturing technology. Twenty‐four zirconia crowns were cemented onto conometric caps with resin‐modified glass ionomer cement, which were then connected with abutments. These specimens were divided into three groups, and each group was subjected to the pull‐out test. A‐control group: 12 specimens directly subjected to pull‐out test; A‐aged group: 12 specimens subjected to thermomechanical aging followed by pull‐out test; A‐repeat group: After the pull‐out, the specimens in the aging group (A‐aged) were reconnected, and the pull‐out test was repeated once more. The remaining 24 zirconia crowns were cemented on standard abutments with zinc phosphate cement, and two groups were formed. C‐control group: 12 specimens directly subjected to the pull‐out test; C‐aged group: 12 specimens subjected to thermomechanical aging followed by pull‐out. Scanning electron microscope (SEM) was used to evaluate the surfaces of caps and abutments. To analyze the data, repeated measures, one‐way ANOVA, and Bonferroni tests were used (p < 0.05). Results: The mean retention force value of the A‐control group was 148.22 ± 16.37 N. The highest mean retention force value was measured in the A‐aged group (204.93 ± 51.67 N), and the lowest mean retention force value was seen in the A‐repeated group (77.02 ± 21.48 N). Thermomechanical aging had a significant influence (p < 0.05) on both systems. No significant differences in retention force were found between the thermomechanical aged groups of both systems (p > 0.05). SEM analysis revealed that aging had an impact on the surface of the conometric system's caps and abutments. Conclusions: The retention force of the conometric system increased significantly following thermomechanical aging. No crown separation occurred during the thermomechanical aging of the conometric system. There was no significant difference in the retention of the conometric and cemented systems after thermomechanical aging. [ABSTRACT FROM AUTHOR]

This study presents a scenario where the embedding of dowel reinforcement for new columns was inadvertently omitted during the casting of concrete columns. This oversight necessitated the implantation of steel reinforcement into pre-existing cast areas. Owing to the high density of the primary slab reinforcement, implantation was feasible only up to half the slab's thickness. By modifying the superplasticizer (SP) dosage during mixing, we achieved a consistent slump of approximately 150 mm across various concrete mixes, ensuring that both slump and slump flow remained within expected limits. The properties of these mixes, both in their fresh and hardened states, are detailed in Table 2. The sieve segregation index consistently remained below 1.3 %, indicating exceptional cohesion in all concrete mixes. In fact, no segregation was observed, with all measured segregation widths being zero. In terms of strength, the cylinder strength increased significantly with the increase in fiber volume from 0 % to 2 %. This study also examines the impact of steel reinforcement, utilizing 8 mm diameter steel bars over a 30 cm length, planted at two different angles (90 and 45 degrees). The concrete column samples were subjected to uniaxial compressive load post-implantation. Results indicate that the implantation process generally led to an increase in the initial compressive strength of the concrete samples. Specifically, specimens with 30 cm reinforcement planted at distances of 55 mm and 35 mm exhibited an average strength increase of 23 % and 17 %, respectively.

The bond between polymer fibers and the surrounding cementitious matrix is essential for the development of concrete reinforcement. The single fiber pull‐out test (SFPT) is the standard characterization technique for testing the bond strength. However, the different phases of debonding cannot be distinguished by the SFPT. This study investigates the debonding of different polymer fibers from the surrounding cementitious matrix with a modified SFPT and proposes methods to change the SFPT setup to generate more valuable information on the debonding mechanism. The SFPT was equipped with linear variable differential transformers (LVDT), digital image correlation (DIC) and acoustic emission (AE) analysis. The results demonstrate that the modified SFPT allows a better understanding of the different phases of debonding during fiber pull‐out. Furthermore, bond strength values calculated by different methods reveal that the chemical bond of the investigated polymers is not different as reported by previous studies. Deformation measurements performed using LVDTs and DIC are suitable measuring techniques to characterize the debonding mechanism in SFPT. A correlation between recorded AE and debonding phases was not found. [ABSTRACT FROM AUTHOR]

Copyright of Journal of Southeast University / Dongnan Daxue Xuebao is the property of Journal of Southeast University Editorial Office and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

The flexural behavior of mortar beams reinforced with coated carbon-fiber textile was experimentally analyzed in this study. Accordingly, pull-out and bending tests were performed on textile-reinforced mortar (TRM) beam specimens. The experimental results demonstrated the superior bond performance of the coated carbon-fiber textile. The TRM beam exhibited sufficient ductility even after the occurrence of flexural cracks. In addition, a theoretical analysis method for predicting the flexural behavior of a TRM beam was established based on the experimentally determined bond behaviors of the textile reinforcement in cementitious materials. The analysis demonstrated that the bending behavior of the TRM beam was reasonably predicted. The results of this study can serve as basic data for the structural application of textile-reinforced cementitious composites. [ABSTRACT FROM AUTHOR]

Based on the self-developed steel fiber position device that can accurately control the spatial position of steel fiber, the effects of steel fiber embedded depth, diameter and embedded angle on the pull-out behavior of steel fiber in ultra-high performance fiber reinforced concrete (UHPFRC) were studied. The results indicate that the maximum pull-out force, pull-out work, maximum pull-out stress and strength utilization rate of steel fiber increase with the increase of steel fiber embedded depth. However, the maximum average bond strength decreases with the increase of steel fiber embedded depth. With the increase of steel fiber diameter, the maximum pull-out force, pull-out work and maximum average bond strength of steel fiber increase correspondingly, while the strength utilization rate and maximum pull-out stress of steel fiber decrease. With the increase of steel fiber embedded angle, the maximum pull-out force and pull-out work of steel fiber increase first and then decrease. The maximum pull-out force and pull-out work reach the maximum value at 45° and 30° of embedded angle, respectively. When the embedded angle is 75°, the failure mode of specimen is that the steel fiber is broken. [ABSTRACT FROM AUTHOR]

Soil nailing is one of the effective methods of slope stabilization, and its stability mainly depends on the properties of both the soil and soil nails. Optimizing soil nailing parameters is an effective task to avoid installation issues. This work uses four input parameters: different shaft diameters, surcharge pressure, helical pitch, and inclination angle. The design plan for the experimentation is conducted using Box Behnken design (BBD) of response surface methodology (RSM), performed in design expert software. In addition, RSM is used to determine the optimal design combinations. A total of 25 experimental runs are taking place, and the significance of the developed quadratic model is determined using the analysis of variance (ANOVA) test. Hybrid deep belief network‐based Coot optimization (DBN‐CO) is also used to optimize the pull‐out capacity and the safety factor during installation for more precised prediction. When compared to others the proposed hybrid DBN‐CO predictive model represents the better performance with regression R = 0.99. Also least MSE & RMSE and highest R & R2 values obtained by hybrid DBN‐CO. The obtained experimental outcomes from RSM are 1.46 of safety factor, and 7.55 kN pull‐out capacity. The predicted results from the proposed hybrid DBN‐CO for the safety factor are 1.44 and pull‐out capacity is 7.77 kN. As a result, the optimal results of DBN‐CO are 3% greater than RSM, DBN, and artificial neural network (ANN). Based on prediction approaches the proposed hybrid DBN‐CO results are in perfect agreement with experimental values and are additional superior to the RSM, DBN, and ANN. [ABSTRACT FROM AUTHOR]

The objective of this study is to examine the mechanical behavior of two-piece abutments (Morse taper with 16° internal angulation and Morse taper with 11.5° internal angulation) before and after cyclic fatigue testing, following ISO 14801:2016 guidelines. The specimens were divided into three groups: a modified Morse taper with a taper angle of 16° (GM group), a conventional Morse taper (taper angle of 11.5° deg) with a two-piece (CMt group), and one-piece abutments (CMo group). Each experimental group was formed by ten implants and ten abutments (n = 10) for a total of 30 specimens (n = 30). The abutments were tightened and loosened, and a fatigue test was applied with 15 Hz and 5 × 106 cycles. Subsequently, the abutments were loosened, and a pull-out test was performed on the CMt group. Finite element analysis (FEA) was conducted on stress concentration regions. The statistical analysis of the loosening test was performed using two-way ANOVA and Tukey's tests (p < 0.05) to compare screw loosening within each group and between the groups with and without mechanical fatigue. Significant differences were found among the three groups in the loosening test when analyzing the values with and without fatigue (p < 0.001) within each group. When the groups were compared with each other, there was also a significant difference between them (p < 0.001), except between groups GM and CMt without fatigue (p = 0.840). In the pull-out test of the CMt group, the sample exhibited frictional locking only after fatigue (mean = 94.2 N). The FEA demonstrated a varied stress distribution in all groups. The stress was found to be more concentrated in the upper third and middle third regions of the implant, as well as in the opposite region of the load application for all three groups. Although the CMo group showed lower rates of loosening, it displayed a poorer stress distribution in comparison to the GM and CMt groups. On the other hand, the CMt group exhibited a satisfactory frictional lock after undergoing the fatigue tests. [ABSTRACT FROM AUTHOR]

Bond Behaviour between GRP Reinforcing Bars and High Performance Aerogel Concrete The bond behavior between reinforcing bars and concrete has a significant influence on the overall load‐bearing behavior as well as the serviceability of reinforced concrete components. Extensive investigations have been carried out in the past for glass fiber reinforced plastics (GRP) in connection with normal concrete (NC). It has been shown that the bond behavior of GRP reinforcement is significantly determined both by the surrounding concrete and by the product‐specific properties (geometry, materials) of the reinforcement bars. For the production of reinforced components made of high‐performance aerogel concrete (HPAC), for which GRP reinforcement elements should preferably be used due to their low thermal conductivity, no studies have been carried out yet. Since it is not possible to simply extrapolate the bond behavior of GRP reinforcement with normal concrete to other types of concrete, 48 pull‐out tests were carried out in the investigations presented below to determine the bond behavior. For comparison with the results from the current state of research, the bond behavior of GRP reinforcement in NC was also determined by means of 24 additional pull‐out tests. Based on the results, analytical bond stress‐slip models were derived for both HPAC and NC. Subsequently, these bond stress‐slip relationships were integrated into a FE model and compared with the results of the experimental investigations. [ABSTRACT FROM AUTHOR]

The bonding characteristics between steel bars and concrete in reinforced concrete (RC) structures are crucial for the prediction of load-bearing capacity for seismic design. Nevertheless, most previous studies on bond-slip performance focus on the bond strength based on the pull-out experiments, it is often overlooked that the effect on the failure modes of RC members and the deformation performance due to the bond characteristics. In this research, the effect of the diameter and its arrangement of the reinforcement of the RC column on the bond failure mode and load-bearing capacity based on the cyclic loading tests and the FE analysis are carried out. In the cyclic loading test, it was found that two RC columns with different diameters and reinforcement arrangements showed distinct load-bearing capacity, deformation performance, and failure mode. Despite those columns having the same longitudinal reinforcement ratios. In addition, by applying an advanced finite element analysis using a bond-slip model that induces splitting failure, we succeeded in reproducing the cyclic deformation behavior and local damage obtained in experiments with high accuracy. The proposed model brings in the advanced prediction of the seismic behavior of RC structures and the enhancement of seismic resistance of social infrastructure facilities to earthquake disasters. [ABSTRACT FROM AUTHOR]

The interaction properties between natural fiber and matrix play an important role in the mechanical performance of composite materials. The adhesion properties and the mechanical interaction between an Ichu fiber (Stipa obtusa) treated with sodium hydroxide and a cementitious matrix were studied by conducting experimental, numerical, and analytical pull-out tests. Through the experimental tests, the force–displacement curve for a fiber length embedded 5 mm deep in the cementitious matrix, maximum force, cohesive parameters, and the type of interface failure were determined. The results were used to calibrate the numerical and analytical models for different lengths of fiber (3, 5, 7, 9, and 11 mm) embedded in the cementitious matrix. The numerical model was implemented in the finite element software Abaqus CAE, and the analytical formulation considered the fiber embedded in a half-space continuous medium. From the experimental test, the force–displacement curve, interfacial shear strength of 0.124 MPa, and the softening type slip were obtained, despite obtaining the hardening-type slip in certain tests. The numerical and analytical results of the load–displacement curve closely approximate the experimental results. This study provides a numerical and analytical model to simulate the alkali-treated Ichu fiber–cementitous matrix interface.

Abstract Bond–slip is an important characteristic that determines the stiffness, displacement, and load-bearing capacity of a reinforced concrete (RC) beam. It is essential for performing a precise numerical analysis of the beam. In most cases, bond–slip models can define the bond–slip curve only when there are experimental data. However, many bond test data have been obtained from pull-out tests, and the dominant view is that the bond–slip behavior observed in the pull-out test is quite different from that in an actual RC beam. Therefore, a mapping function that makes it possible to estimate the bond–slip behaviors of beam specimens using those of pull-out specimens was developed in this study. A total of 255 pull-out specimen data and 75 beam specimen data were collected from previous studies, and the importance and influence of each feature of the two groups were analyzed using random forest and K-means clustering. The mapping function was derived using genetic programming, and its accuracy was verified through a comparison with existing models. The proposed model exhibits a high degree of accuracy in estimating bond–slip and bond strength in beam specimens and can provide useful information for understanding the difference in bond–slip behaviors between the two groups.

The transient and static anti-plane problem of a rigid line inclusion pulled out from an elastic medium is studied. The singular integral equation method is used to solve the stress field. Under the static load, the stress intensity factor (SIF) at the inclusion tips increases with the medium length. The problem becomes equivalent to an inclusion in a medium with an infinite length when the length of the medium is 3.5 times longer than that of the inclusion. However, under the transient load, the maximum value of the SIF occurs when the medium length is about two times the inclusion length. Besides, the relation between the pull-out force and the anti-plane displacement is given. The conclusions are useful in guiding the design of fiber reinforced composite materials. [ABSTRACT FROM AUTHOR]

Soil profile moisture is a crucial parameter of agricultural irrigation. To meet the demand of soil profile moisture, simple fast-sensing, and low-cost in situ detection, a portable pull-out soil profile moisture sensor was designed based on the principle of high-frequency capacitance. The sensor consists of a moisture-sensing probe and a data processing unit. The probe converts soil moisture into a frequency signal using an electromagnetic field. The data processing unit was designed for signal detection and transmitting moisture content data to a smartphone app. The data processing unit and the probe are connected by a tie rod with adjustable length, which can be moved up and down to measure the moisture content of different soil layers. According to indoor tests, the maximum detection height for the sensor was 130 mm, the maximum detection radius was 96 mm, and the degree of fitting (R2) of the constructed moisture measurement model was 0.972. In the verification tests, the root mean square error (RMSE) of the measured value of the sensor was 0.02 m3/m3, the mean bias error (MBE) was ±0.009 m3/m3, and the maximum error was ±0.039 m3/m3. According to the results, the sensor, which features a wide detection range and good accuracy, is well suited for the portable measurement of soil profile moisture. [ABSTRACT FROM AUTHOR]

This paper presents a study about fiber slippage behavior under direct pull-out and assessment of fiber/matrix pull-off bond strength. This study was prepared through theoretical calculations validated by experimental tests. Theoretically, the study shows a general solution for the fiber-slip mechanism in a general matrix using a new frictional-shear-lag model and an analytical model for pull-off bond strength. Experimentally, pull-out tests were conducted for selected types of single fiber in micro-level (glass, carbon, and short-steel fiber); and macro-level (straight steel fiber). The results showed significant improvements in the pull-off bond strength using novel shape of fiber with wide rounded ends-WESF. The pull-off bond strength in normal-weight concrete was found lower than in lightweight concrete, and the matrix with higher compressive strength improves the pull-off bond strength. Also, the steel fiber showed higher pull-off bond strength compared to glass and carbon fiber; whereas the efficiency of short-steel fiber was higher than the long one. All types of fiber showed that the higher aspect ratio reduces the pull-off bond strength. Using the novel-WESF, the performance of fiber-slip improved 52.65% in normal-weight concrete. Moreover, the fiber-slip performance improved 61.79% in sand-lightweight concrete, and 70.20% in all other types of light-weight concrete. [ABSTRACT FROM AUTHOR]

The steel-concrete interface (SCI) is extensively acknowledged to affect the durability of reinforced concrete. The main objective of this paper is to conduct a state-of-the-art review that contributes to sufficient knowledge on the determination of the SCI properties and its effect on the overall performance of reinforced concrete elements. The physical characteristics at the SCI are influenced by segregation, flow, hydration, and drying shrinkage of concrete, hence affecting the presence of voids and cracks within this interface. The bond strength is one of the measures of the SCI and this is conducted through pull-out, push-in, and tie-beam testing. It was shown that the rebar shape and diameter, the anchorage length, the concrete grade strength, binder type (geopolymer concrete), and the distribution of aggregates have a significant effect on the interface properties and behavior, where geopolymer concrete offered improved bond behavior over conventional concrete. Various studies have demonstrated that the presence of the steel-concrete interface and the application of mechanical stresses contribute to the flow transfer (inflow/outflow) through the reinforced concrete structure. Some of these studies focused on the initial state of the SCI within the structure, and some conducted tests with shear loading on the SCI. Regarding the transfer properties at the SCI, it was shown that the presence of steel rebar, crack dimensions, degree of saturation of concrete, and the concrete mix design, influence the permeability of the concrete, specifically at the vicinity of the SCI, because of the development of micro-cracks at the interface. In other studies, the shear stresses were also found to affect the transfer properties through the SCI. Researchers have implemented several software solutions such as finite element models on ABAQUS and mesoscale numerical simulations and have used machine learning models that predict and verify the effects of bond failure behavior at the SCI. Good agreement was established between the numerical and actual experimental results. The influence of different exposure conditions on the steel-concrete interface that change throughout time needs to be dealt with, which includes moisture-related environmental conditions, variation in temperature, and chemical exposure. Furthermore, the influence of structural loading, such as "creep effect", deterioration (ageing) of material must be studied at the interface. The studies were limited to short-term behavior. [ABSTRACT FROM AUTHOR]

Recently, innovations in textile-reinforced concrete (TRC), such as the use of basalt textile fabrics, the use of high-performance concrete (HPC) matrices, and the admixture of short fibers in a cementitious matrix, have led to a new material called fiber/textile-reinforced concrete (F/TRC), which represents a promising solution for TRC. Although these materials are used in retrofit applications, experimental investigations about the performance of basalt and carbon TRC and F/TRC with HPC matrices number, to the best of the authors' knowledge, only a few. Therefore, an experimental investigation was conducted on 24 specimens tested under the uniaxial tensile, in which the main variables studied were the use of HPC matrices, different materials of textile fabric (basalt and carbon), the presence or absence of short steel fibers, and the overlap length of the textile fabric. From the test results, it can be seen that the mode of failure of the specimens is mainly governed by the type of textile fabric. Carbon-retrofitted specimens showed higher post-elastic displacement compared with those retrofitted with basalt textile fabrics. Short steel fibers mainly affected the load level of first cracking and ultimate tensile strength. [ABSTRACT FROM AUTHOR]

The statistical study of the glued-in rod splice connection for Mengkulang glulam timber is presented in this research. This type of connection is used in many applications, such as bridge construction and wide hall, besides becoming increasingly popular due to its cost-effectiveness and ease of installation. Using statistical analysis to evaluate the performance of glued-in rod splice connections is relatively new. Statistical analysis can assess the connection's performance by examining the glued-in rod splice connection's strength, stiffness, and durability. Glued-in rods have several advantages over traditional mechanical connections generally used in beam design, such as higher stiffness, more uniform stress distribution, fewer rod corrosion problems and better appearance. Due to this limitation, the standard design for glued-in rods using glulam is the estimated extrapolation for solid timber guidelines. The main objectives of this research were to develop the pull-out model and validate the effectiveness of the model equation for glued-in rods parallel (GRPS0°) and perpendicular (GRPS90°) to the grain directions using a statistical package for the social sciences (SPSS). The variables examined were the number of rods, diameter, length, spacing, the kind of glue utilised, and the number of adhesive layers. In conclusion, the model development clearly shows that most of the parameters achieved the R2 more than 80% accurate for both parallel (GRPS0°) and perpendicular (GRPS90°) to the grain directions. [ABSTRACT FROM AUTHOR]

In steel fiber reinforced concrete, the interface is a very complex and weak structure. It is because of the weak interface layer between the steel fiber and the matrix that the reinforcing and toughening properties of the steel fiber cannot be fully exerted. The interface bond performance is the core of the meso-mechanical properties of steel fiber reinforced concrete. To study its influence on the mechanical properties of steel fiber reinforced concrete, three-phase finite element models of steel fiber pull-out are established based on the cohesive zone model and unified phase-field theory by means of FEM in this paper. The interface bond is simulated by a zero-thickness cohesive element, and the pull-out process of steel fiber in the concrete matrix is analyzed to provide a basis for the fracture research of steel fiber reinforced concrete. In this paper, the influence of factors such as the embedment depth, length–diameter ratio, embedment angle, and interface properties of steel fibers on the pull-out mechanical properties of steel fibers are considered, and the relevant finite element models are established to conduct numerical simulations of the pull-out process of steel fibers. The numerical simulation results are in good agreement with the experimental results, and this verifies the reliability of the model. The results show that the steel fiber pull-out finite element model established by the cohesive zone model and phase-field regularized cohesive zone model (PF-CZM) has a certain reliability; the peak pull-out load of the steel fiber increases with an increase in the embedment depth of the steel fiber, and decreases with an increase in the length–diameter ratio and embedment angle of the steel fiber; by controlling the strength of the interface layer and the concrete matrix, the reinforcement effect of the steel fiber on the concrete matrix can be improved; and the PF-CZM has a good characterization of the damage and failure evolution process of the concrete matrix. [ABSTRACT FROM AUTHOR]

The bond behaviors of recycled aggregate concrete-filled steel tube (RACFST) stub columns after exposure to high temperatures were investigated based on the push-out experimental tests of 36 heated and six unheated RACFST specimens. The influences of five variable parameters, that is, temperature level, replacement ratio of recycled coarse aggregate (RCA), cross-section type, concrete strength and interface length, on the bond strength and bond stress-slip curves were discussed. Results suggest that the bond stress-slip curves of push-out RACFST specimens at high temperature differ from those at ambient temperature. Additionally, the bond strength was found to increase with increasing temperature. The bond strength at a high temperature of 800°C is about 3 times higher than that at room temperature. The bond strength can be increased up to 2.6 times after high temperature with the same RAC replacement ratio. Based on the experimental results, regression analysis was conducted to develop a bond strength model to predict the bond behavior between recycled aggregate concrete and steel tube after exposure to high temperatures. [ABSTRACT FROM AUTHOR]

Background This study was performed to identify the incidence of screw in-type lateral anchor pull-out in patients older than 60 years who underwent rotator cuff repair for large to massive rotator cuff tear (RCT). Methods We reviewed 25 patients over 60 who were diagnosed with large to massive RCT and underwent arthroscopic rotator cuff repair in our hospital from March 2017 to February 2021. Preoperative tear size (anterior to posterior, medial to lateral) was measured via preoperative magnetic resonance imaging (MRI). All 25 patients underwent MRI scanning on postoperative day 1 and at 3 months after surgery. The change of anchor position was measured in axial views on MRI images postoperative day 1 and 3 months after surgery. And it was statistically compared according to bone mineral density (BMD), sex, and number of lateral anchors. Results Two MRIs (postoperative day 1 and 3 months) in 25 patients were compared. Anchor pull-out occurred in six patients during 3 months (6.7%), and the mean pull-out length difference was 1.56 mm (range, 0.16–2.58). There was no significant difference in the number of pull-out anchors, degree of pull-out difference by comparing BMD (A, BMD≤-2.5; B, BMD>-2.5), sex, or number of anchors used in each surgery (C, two anchors; D, three anchors) (p>0.05). Conclusions Pull-out of screw in-type anchors was rarely observed and the mean pull-out length difference was negligibly small in our study. The screw in-type lateral anchor seems to be a decent option without concern of anchor pull-out even in elderly patients.

In applications such light train application, sandwich materials require mechanical joints. One major load produced at the mechanical joining is the pull-out load. The scope of this literature review includes pull-out test results, failure mode during the pull-out test, failure load parameters, and an analytical method to determine the maximum pull-out load. The pull-out resistance of the mechanical joint on sandwich material is determined by the failure load and the maximum load. The failure modes on sandwich material include core buckling, shear cracking, tensile rupture and delamination. The failure load of mechanical joints on the sandwich material will increase as insert depth, insert diameter, core thickness and core density increase. Meanwhile, two analytical methods (Aerospace Engineering and Zenkert Methods) are studied, and it is found that the Aerospace Engineering is more accurate. The multiplier for the maximum load value has been found to determine the failure load. [ABSTRACT FROM AUTHOR]

The recent application of deep learning for structural health monitoring systems for damage detection has potential for improvised structure performance and maintenance for long term durability, and reliable strength. Advancements in electro-mechanical impedance (EMI) techniques have sparked attention among researchers to develop novel monitoring techniques for structural monitoring and evaluation. This study aims to determine the performance of EMI techniques using a piezo sensor to monitor the development of bond strength in reinforced concrete through a pull-out test. The concrete cylindrical samples with embedded steel bars were prepared, cured for 28 days, and a pull-out test was performed to measure the interfacial bond between them. The piezo coupled signatures were obtained for the PZT patch bonded to the steel bar. The damage qualification is performed through the statistical indices, i.e., root-mean-square deviation (RMSD) and correlation coefficient deviation metric (CCDM), were obtained for different displacements recorded for axial pull. Furthermore, this study utilizes a novel Convolutional Neural Network-Long Short-Term Memory (CNN-LSTM)-based hybrid model, an effective regression model to predict the EMI signatures. These results emphasize the efficiency and potential application of the deep learning-based hybrid model in predicting EMI-based structural signatures. The findings of this study have several implications for structural health diagnosis using a deep learning-based model for monitoring and conservation of building heritage. [ABSTRACT FROM AUTHOR]

Due to the benefits it provides to concrete technology, environment and economy, the use of industrial byproducts and waste materials such as fly ash and waste vehicle tires has been widely accepted in the construction sector. In this study, the effect of using 5%, 10% and 15% fly ash instead of cement as binder on the fresh and hardened properties of concretes where waste tire is used as 5%, 10% and 15% by volume instead of fine aggregate was investigated. Unit volume weight and consistency properties were determined in the fresh state, and adherence by the pull-out method, compressive and bending strength were determined in the hardened state. As a result, depending on the increase in the amount of tire, the unit weight of fresh concrete decreased and the amount of slump increased, while the compressive, adherence and flexural strengths and modulus of elasticity decreased in hardened concrete. However, fly ash substitution provided an improvement in compressive strength and prevented strength losses. The use of 10% fly ash increased the compressive strength by approximately 30% in concretes with 10% and 15% tire additives. Fly ash increased the adherence strength by 16% and 25%, respectively, in 10% and 15% tire additives. In general, 10% fly ash provided improvement by reducing strength losses in tire-added concretes. The use of fly ash and waste tire in optimum proportions contributes to the usability of tire additives in concrete technology by improving the physical and mechanical properties of tire-added concretes. [ABSTRACT FROM AUTHOR]

Carbon nanotubes (CNTs) are widely used as reinforcements in cement-based composites. The improvement in the mechanical properties of the resulting materials depends on the characteristics of the interface formed between CNTs and the cement matrix. The experimental characterization of the interfacial properties of these composites is still limited and hard to achieve with currently available technologies. In this work, molecular dynamics and molecular mechanics pull-out simulations of pristine and functionalized CNTs, taken from a tobermorite crystal, were carried out to study interfacial shear strength (ISS) from an atomic perspective. ISS was calculated from the potential energy of the systems. The effects of the CNT diameter and the degree of functionalization on the pull-out process were analyzed according to the ISS and non-bonded energy results. The influence of H-bonding and electrostatic interactions between the CNT and the matrix were also studied. The results show that ISS decreases with increasing CNT radius for pristine CNTs and depends upon the number of H-bonds for functionalized CNTs. ISS values are positively correlated to Enon-bonded energy, which is related to the number of carboxyl groups on the CNT surface. A high degree of functionalization increases both the number of H-bonds and the number of Ca2+-O interactions between the CNT and the tobermorite surface. This results in a stronger interfacial interaction and, therefore, an elevated ISS value. [ABSTRACT FROM AUTHOR]

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