Loading Tests Research Articles

Precision Calibration and Linearity Assessment of Thin Film Force-Sensing Resistors

In this study, we thoroughly analyzed the linearity and repeatability of force-sensing resistor (FSR) sensors through static load tests to ensure their reliability. The novelty of this research lies in its comprehensive evaluation and direct comparison of two widely used FSR sensors, i.e., Flexiforce A201-1 and Interlink FSR-402, under various loading conditions by employing a robust calibration methodology. This study provides detailed insights into the sensors’ performances, offering practical calibration equations that enhance measurement precision and reliability, which have not been extensively documented in previous studies. Our results demonstrate that the linearity of thin film FSR sensors is highly accurate, closely resembling a straight line. We employed M1 Class weights, applying loads ranging from 20 g to 300 g. The resistance of the FSR sensors, which varies with the applied load, was measured using a voltage divider circuit and an analog-to-digital converter of a microcontroller. MATLAB was used to calculate the average output voltage for each applied load and fixed resistance. Additionally, we examined the relationships among load, FSR sensor resistance, and conductivity. Our research indicates that with precise calibration, thin film FSR sensors can be highly reliable for force measurement applications.

Hepatitis B clinical care provision in pregnancy: A whole-of-population linkage study in Victoria, Australia.

Pregnancy is a key setting for engagement in chronic hepatitis B (CHB) care, due to the implications for transmission to the infant and antenatal diagnosis representing an opportunity for ongoing follow-up. This study aimed to identify the coverage and predictors of clinical care for women with CHB during and after pregnancy in a population-level cohort. Notified CHB cases in Victoria, Australia, were linked with hospitalizations, medical services, and prescribing data, covering the period 1991-2018. Women with an admission for a live birth were identified and services provided during pregnancy were assessed, including general practitioner (GP) or specialist visits, viral load and serology testing, and antiviral treatment. Viral load and serology testing coverage ware also assessed for the 2-year period following pregnancy. Demographic and clinical predictors of viral load testing during pregnancy were assessed. A total of 11015 birth events occurred for 6090 women with CHB. During pregnancy most had a GP consultation (91.6%); however, only 39.5% had viral load testing and 41.4% had a gastroenterology or infectious diseases specialist consultation. Viral load testing and serology testing in the 2years after pregnancy occurred in approximately half (47.9% and 52.2%, respectively) with increases over time. Viral load testing was more likely in those born overseas, those with more than one previous birth, and those living in Melbourne. Despite improvements over time, key gaps were identified in the provision of CHB clinical care during and after pregnancy, with implications for ongoing transmission and adverse outcomes.

The Influence of Cyclic Loading on the Mechanical Properties of Well Cement

The cyclic loading generated by injection and production operations in underground gas storage facilities can lead to fatigue damage to cement sheaths and compromise the integrity of wellbores. To investigate the influence of cyclic loading on the fatigue damage of well cement, uniaxial and triaxial loading tests were conducted at different temperatures, with maximum cyclic loading intensity ranging from 60% to 90% of the ultimate strength. Test results indicate that the compressive strength and elastic modulus of well cement subjected to monotonic loading under high-temperature and high-pressure (HTHP) testing conditions were 14–21% lower than those obtained under ambient testing conditions. The stress–strain curve exhibits stress–strain hysteresis loops during cyclic loading tests, and the plastic deformation capacity is enhanced at HTHP conditions. Notably, a higher intensity of cyclic loading results in more significant plastic strain in oil-well cement, leading to the conversion of more input energy into dissipative energy. Furthermore, the secant modulus of well cement decreased with cycle number, which is especially significant under ambient test conditions with high loading intensity. Within 20 cycles of cyclic loading tests, only the sample tested at a loading intensity of 90% ultimate strength under an ambient environment failed. For samples that remained intact after 20 cycles of cyclic loading, the compressive strength and stress–strain behavior were similar to those obtained before cyclic loading. Only a slight decrease in the elastic modulus is observed in samples cycled with high loading intensity. Overall, oil-well cement has a longer fatigue life when subjected to HTHP testing conditions compared to that tested under ambient conditions. The fatigue life of well cement increases significantly with a decrease in loading intensity and can be predicted based on the plastic strain evolution rate.

Biomechanical Comparisons between One- and Two-Compartment Devices for Reconstructing Vertebrae by Kyphoplasty

Background: This biomechanical in vitro study compared two kyphoplasty devices for the extent of height reconstruction, load-bearing capacity, cement volume, and adjacent fracture under cyclic loading. Methods: Multisegmental (T11–L3) specimens were mounted into a testing machine and subjected to compression, creating an incomplete burst fracture of L1. Kyphoplasty was performed using a one- or two-compartment device. Then, the testing machine was used for a cyclic loading test of load-bearing capacity to compare the two groups for the amount of applied load until failure and subsequent adjacent fracture. Results: Vertebral body height reconstruction was effective for both groups but not statistically significantly different. After cyclic loading, refracture of vertebrae that had undergone kyphoplasty was not observed in any specimen, but fractures were observed in adjacent vertebrae. The differences between the numbers of cycles and of loads were not statistically significant. An increase in cement volume was strongly correlated with increased risks of adjacent fractures. Conclusion: The two-compartment device was not substantially superior to the one-compartment device. The use of higher cement volume correlated with the occurrence of adjacent fractures.

Assessment of the utilization of cement-treated geotextile as a reinforcement element for highway base layer under cyclic loading

This study conducted large-scale cyclic loading experiments on the base layer overlying a weak subgrade soil. Geotextile and cement-treated geotextile were utilized to reinforce the base material and to separate the interface of soils between the base layer and the subgrade. The results obtained from the repeated loading tests using geotextile and cement-treated geotextile were analyzed and evaluated in terms of some benchmark indicators such as total deformation, permanent deformation, elastic deformation, percentage of elastic deformation, traffic benefit ratio (TBR), elastic modulus (MR), improvement factor (If), and rut depth reduction ratio (RDR). Based on the experimental results, the use of cement-treated geotextile as a base layer reinforcement element or as an interfacial separation element demonstrated better performance compared to the use of geotextile. Utilization of a cement-treated geotextile as both reinforcement and separation element resulted in an RDR value of 49.26 % after 5000 cycles. Additionally, using a cement-treated geotextile for both reinforcement and separation increased the TBR value to 14.62 at 27 mm deformation, decreased the permanent deformation value from 53.67 mm to 27.23 mm, and approached approximately 2 improvement factor values, compared to using the geotextile solely for separation.

Cyclic loading test on hysteresis performance of replaceable link with slit web

The paper introduces a novel design for replaceable links, which incorporates strategically placed slits in the web to reduce the bearing capacity of the link. This design innovation ensures localized plastic deformation within the link, facilitating disassembly and replacement after earthquake. Two types of steel materials, Q235 steel, and LYP160 steel, are employed in constructing the replaceable links. Three replaceable links with slit web were designed according to the material properties of the steel and the number of slits and were subjected to cyclic loading tests. The test results show that the primary failure modes of the link include web failure between slits, torsional deformation of the web between slits, slight buckling of flanges and stiffeners, and web tearing. The material overstrength coefficients of the three specimens range from 0.83 – 1.41, and the overstrength coefficients due to strain hardening range from 1.08 – 2.49, with a maximum plastic rotation reaching up to 0.16 rad.

Trends and correlates in HIV viral load monitoring and viral suppression among adolescents and young adults in Dar es Salaam, Tanzania.

Adolescents and young adults (AYA) living with HIV have been shown to have lower rates of viral load testing and viral suppression as compared to older adults. We examined trends over time and predictors of HIV viral load monitoring and viral suppression among AYA in a large HIV treatment programme in Dar es Salaam, Tanzania. We analysed longitudinal data of AYA aged 10-24 years initiated on antiretroviral therapy between January 2017 and October 2022. Trend models were used to assess changes in HIV viral load testing and viral suppression by calendar year. Generalised estimating equations were used to examine the relationship of sociodemographic and clinical factors with HIV viral load testing and viral suppression. Out of 15,759 AYA, the percentage of those who received a 6-month HIV viral load testing increased from 40.6% in 2017 to 64.7% in 2022 and, a notable annual increase of 5.6% (p < 0.001). A higher HIV viral load testing uptake was observed among 20- to 24-year-olds (87.7%) compared to 10- to 19-year-olds (80.2%) (p < 0.001). The likelihood of not receiving an HIV viral load test within 12 months of antiretroviral therapy initiation was higher among 10- to 19-year-olds (adjusted odds ratio [aOR] = 1.7; 95% confidence interval [CI] = 1.4-2.0), advanced HIV disease (aOR = 1.3; 95% CI = 1.12-1.53), normal nutrition status at enrolment aOR 2.6 (95% CI = 1.59-4.26) and initiation of non-nucleoside reverse transcriptase inhibitors regimen aOR 1.2 (95% CI = 1.08-1.34). The proportion of AYA with viral suppression increased from 83.0% in 2017 to 94.6% in 2022. Notably, the overall trend in viral suppression increased significantly at 2.4% annually. The risk of not achieving viral suppression was greater among 10- to 14-year-olds (aOR = 2; 95% CI = 1.75-2.43) and 15- to 19-year-olds (aOR = 1.4; 95% CI = 1.24-1.58) as compared to 20-24 years; being male (aOR = 1.16; 95% CI = 1.02-1.32); undernourished (aOR = 1.53; 95% CI = 1.17-1.99); in WHO Stage II (aOR = 1.16; 95% CI = 1.02-1.33) and III (aOR = 1.21; 95% CI = 1.03-1.42) and being on an non-nucleoside reverse transcriptase inhibitors regimen (aOR = 1.32; 95% CI = 1.18-1.48). HIV viral load testing uptake at 6 months of antiretroviral therapy initiation and viral suppression increased from 2017 to 2022; however, overall HIV viral load testing was suboptimal. Demographic and clinical characteristics can be used to identify AYA at greater risk for not having HIV viral load test and not achieving viral suppression.

Strength characteristics of different stress spaces of red sandstone under loading and unloading tests

Red sandstone tests were conducted on the rock mechanics test system to clarify the strength and failure characteristics of red sandstone under triaxial loading and different unloading confining pressure rates. Strength change rules of the red sandstone in various stress spaces were analyzed. Results show that a large initial confining pressure indicates a long yield section and large axial strain. A small unloading confining pressure rate indicates a long yield section and large axial strain at failure under the identical initial confining pressure. The confining pressure reduction increases with the unloading confining pressure rate increasing when the red sandstone fails. The stress path of unloading confining pressure weakens the red sandstone cohesion and strengthens its internal friction angle. The general octahedral shear stress formula for judging whether the red sandstone fails under loading and different unloading rates was acquired on the basis of the octahedral shear stress characteristics of the red sandstone. In addition, a 3D empirical criterion for evaluating the red sandstone strength was constructed through the deviator plane function of Eekelen and the strength envelope curve on the meridian plane. A great initial confining pressure indicates serious internal damage of the red sandstone at failure under the identical unloading rate of confining pressure. A low unloading rate of confining pressure indicates internal serious damage of the red sandstone at failure when the initial confining pressure is the same. The analysis of macroscopic failure characteristics revealed that the stress path significantly influences the failure mechanism of the red sandstone. The results are instructive for determining the stability of underground engineering of the red sandstone.

Local scour effects on seismic behavior of pile-group foundations in cohesionless soils: Insights from quasi-static tests

Local scour has been reported as a common phenomenon for pile-group foundations in marine, coastal, and riverine sites, while its effects on the seismic behavior of pile-group foundations are yet to be well documented. This paper reported a pair of quasi-static cyclic loading tests on 2 × 3 scoured pile-group foundation specimens, one in global scour and the other in local scour, to understand the influence of local scour on the seismic behavior, particularly in terms of soil-pile interaction features and failure mechanisms. Test results indicate a flexural failure mode for both specimens. Local scour does not change the order of limit states but postpones the occurrence of concrete cover cracking and rebar yielding due to the reduced lateral stiffness of the locally scoured piles. Moreover, local scour rarely changes the aboveground damage regions at the top of outer piles (one time the side length of squared pile section, D), but significantly aggravates and deepens the underground damage regions at outer piles (from 4 ∼ 5D for global scour to 3.7 ∼ 6D for local scour). Besides, local scour reduces the displacement ductility factor from 2.50 to 1.25 for the Easy-to-Repair limit state, resulting in adverse impacts on pile-group foundations in general.

Seismic strategy of non-seismically designed reinforced concrete columns retrofitted with steel rods

This paper presents experimental results of combined cyclic load testing on a reinforced concrete (RC) column that was retrofitted with newly designed steel rods. The steel rods were installed around the column longitudinally and then anchored. The proposed steel rods utilize simple components and installation to enhance both the strength and ductility of RC columns. Cyclic lateral load tests were conducted on three specimens: one unreinforced specimen as reference, one specimen with the entire length of the column retrofitted, and one specimen with only the plastic hinge region of the column retrofitted. All specimens were tested under eccentric constant axial load and incrementally increasing lateral loading cycles with eccentricity. The implementation of steel rods resulted in significant improvement in ductility and an up to 60% increase in ultimate loading capacity.

Numerical Prediction of Ride Comfort of Tracked Vehicle Equipped with Novel Flexible Road Wheels

Enhancing ride comfort has always constituted a crucial focus in the design and research of modern tracked vehicles, heavily reliant on the driving system’s performance. While the road wheel is a key component of the driving system, traditional road wheels predominantly adopt a solid structure, exhibiting subpar adhesion performance and damping effects, thereby falling short of meeting the demands for high-speed, stable, and long-distance driving in tracked vehicles. Addressing this issue, this paper proposes a novel type of flexible road wheel (FRW) characterized by a catenary construction. The study investigates the ride comfort of tracked vehicles equipped with flexible road wheels by integrating finite element and vehicle dynamic. First, three-dimensional (3D) finite element (FE) models of both flexible and rigid road wheels are established, considering material and contact nonlinearities. These models are validated through a wheel radial loading test. Based on the validated FE model, the paper uncovers the relationship between load and radial deformation of the road wheel, forming the basis for a nonlinear mathematical model. Subsequently, a half-car model of a tracked vehicle with seven degrees of freedom is established using Newton’s second law. A random road model, considering the track effect and employing white noise, is constructed. The study concludes by examining the ride comfort of tracked vehicles equipped with flexible and rigid road wheels under various speeds and road grades. The results demonstrate that, in comparison to the rigid road wheel (RRW), the flexible road wheel enhances the ride comfort of tracked vehicles on randomly uneven roads. This research provides a theoretical foundation for the implementation of flexible road wheels in tracked vehicles.

A Study of Single Stone Column Bearing Capacity from a Full-Scale Plate Load Test in Long Son Project

A Study of Single Stone Column Bearing Capacity from a Full-Scale Plate Load Test in Long Son Project

Sexual orientation, gender identity and virologic failure among people with HIV: a cohort study in all of US research program

BackgroundSexual and gender minorities (SGMs) are at higher risk of HIV incidence compared to their heterosexual cisgender counterparts. Despite the high HIV disease burden among SGMs, there was limited data on whether they are at higher risk of virologic failure, which may lead to potential disease progression and increased transmission risk. The All of Us (AoU) Research Program, a national community-engaged program aiming to improve health and facilitate health equity in the United States by partnering with one million participants, provides a promising resource for identifying a diverse and large volunteer TGD cohort. Leveraging various data sources available through AoU, the current study aims to explore the association between sexual orientation and gender identity (SOGI) and longitudinal virologic failure among adult people with HIV (PWH) in the US.MethodsThis retrospective cohort study used integrated electronic health records (EHR) and self-reported survey data from the All of Us (AoU) controlled tier data, version 7, which includes participants enrolled in the AoU research program from May 31, 2017, to July 1, 2022. Based on participants’ sexual orientation, gender identity, and sex assigned at birth, their SOGI were categorized into six groups, including cisgender heterosexual women, cisgender heterosexual men, cisgender sexual minority women, cisgender sexual minority men, gender minority people assigned female at birth of any sexual orientation, and gender minority people assigned male at birth of any sexual orientation. Yearly virologic failure was defined yearly after one’s first viral load testing, and individuals with at least one viral load test > 50 copies/mL during a year were defined as having virologic failure at that year. Generalized linear mixed-effects models were used to explore the association between SOGI and longitudinal virologic failure while adjusting for potential confounders, including age, race, ethnicity, education attainment, income, and insurance type.ResultsA total of 1,546 eligible PWH were extracted from the AoU database, among whom 1,196 (77.36%) had at least one viral failure and 773 (50.00%) belonged to SGMs. Compared to cisgender heterosexual women, cisgender sexual minority women (adjusted Odds Ratio [aOR] = 1.85, 95% CI: 1.05–3.27) were at higher risk of HIV virologic failure. Additionally, PWH who were Black vs. White (aOR = 2.15, 95% CI: 1.52–3.04) and whose insurance type was Medicaid vs. Private insurance (aOR = 2.07, 95% CI: 1.33–3.21) were more likely to experience virologic failure.ConclusionsMaintaining frequent viral load monitoring among sexual minority women with HIV is warranted because it allows early detection of virologic failure, which could provide opportunities for interventions to strengthen treatment adherence and prevent HIV transmission. To understand the specific needs of subgroups of SGMs, future research needs to examine the mechanisms for SOGI-based disparities in virologic failure and the combined effects of multi-level psychosocial and health behavior characteristics.

Enhancing Quality Management of PHC Piles through Improved Driving Formulas: A Comprehensive Review and Analysis

In construction projects, conducting dynamic load tests on all piles proves impractical. Selective testing estimates bearing capacity, while the remaining piles rely on penetration depth for management. This approach, however, faces reliability issues due to varying conditions among piles. Technological advancements, such as non-contact hammers and sensors, have enhanced the accuracy of penetration depth measurements during final driving. Nonetheless, relying solely on penetration depth for construction and quality management remains problematic. This study, therefore, focuses on enhancing the use of driving formulas to improve pile quality management, particularly for the widely used pre-stressed high-strength concrete (PHC) piles. To improve pile quality management, existing driving formulas underwent review and refinement. Utilizing 258 dynamic load test data from various sites, the Hiley, Gates, and Danish formulas underwent validation through statistical analysis and graphical comparison. Enhancements to the Gates formula, achieved through curve fitting with actual data and the application of segment-based coefficients, demonstrated increased accuracy in bearing capacity estimation. These improvements offer a more reliable approach to pile quality management in construction projects.

Human rights health care measures reporting physical fitness test for ages 6 to 17 with 10-year follow-up

Purpose This study aims to compare the physical fitness test results of Japanese children in 2008 and 2018 to narrow the gap between life expectancy and healthy life expectancy and extend healthy life expectancy. In addition, this paper sought to explore the potential of implementing health education programs as a new social context to promote race equality and human rights in health and social care. Design/methodology/approach This study was conducted in 2008 and 2018 in Nagano Prefecture, Japan. Physical fitness tests related to growth and development were administered to participants aged 6–17 years. Findings Physical fitness measurements in 2018, specifically those for walking ability and endurance, were significantly inferior to those in 2008. In a gender-specific analysis, boys outperformed girls in muscle strength, muscle endurance, walking ability and endurance tests, while girls outperformed boys in the balance test. Research limitations/implications Most of the junior and senior high school students who participated in the EO test exceeded the upper limit of 120 s, suggesting that the load of the measurement method is low and improvement is necessary. In 2018, a large variation in 6M results was observed among participants, possibly due to the differences in the level of seriousness during the 6M test. Therefore, to ensure that junior and senior high school students properly perform the EO and 6M tests, it is necessary to devise an effective method of implementation, such as changing the physical fitness test load. Originality/value Mere health education is ineffective to address health inequalities. Addressing structural factors is essential to avoid unintended consequences such as increasing the gap between groups of people. However, one way to extend healthy life expectancy is to improve overall health, including differences in the health status of groups due to differences in region and socioeconomic status.

Application of the outlier detection method for web-based blood glucose level monitoring system

Recent advancements in biosensors have empowered individuals with diabetes to autonomously monitor their blood glucose levels through continuous glucose monitoring (CGM) sensors. Nevertheless, the data collected from these sensors may occasionally include outliers due to the inherent imperfections of the sensor devices. Consequently, the identification of these outliers is critical to determine whether blood glucose levels deviate significantly from the norm, necessitating further action. This study employs an outlier detection approach based on the 3-sigma method and the interquartile range (IQR), along with the application of the Winsorizing technique to correct the identified outliers. Additionally, a web-based system for visualizing blood glucose levels is developed, utilizing both outlier detection methods. In order to assess the system's performance, two types of testing are conducted: black box testing and load testing. The results of black box testing indicate that all test scenarios operate as anticipated. As for the load testing response times, it is observed that the 3-sigma visualization page loads an average of 606.75 milliseconds faster compared to the IQR visualization page. This study's outcomes are expected to enhance data quality, enhance the precision of analyses, and facilitate more informed decision-making by identifying and addressing extreme data points.

The Effects of Unitizing Nail-Plate Constructs in Distal Femur Fractures: A Biomechanical Study.

To assess the biomechanical differences between linked and unlinked constructs in young and osteoporotic cadavers in addition to osteoporotic sawbones. Intraarticular distal femur fractures with comminuted metaphyseal regions were created in three young matched pair cadavers, three osteoporotic matched pair cadavers, and six osteoporotic sawbones. Precontoured distal femur locking plates were placed in addition to a standardized retrograde nail, with unitized constructs having one 4.5 mm locking screw placed distally through the nail. Nonunitized constructs had seven 4.5 mm locking screws placed through the plate around the nail, with one 5 mm distal interlock placed through the nail alone. Cadaveric specimens were subjected to axial fatigue loads between 150 and 1500 N (R Ratio = 10) with 1 Hx frequency for 10,000 cycles. Sawbones were axially loaded at 50% of the ultimate load for fatigue testing to achieve runout, with testing performed with 30 and 300 N (R Ratio = 10) loads with 1 Hz frequency for 10,000 cycles. In young cadavers, there was no difference in the mean cyclic displacement of the unitized constructs (1.51 ± 0.62mm) compared to the non-unitized constructs (1.34 ± 0.47mm) (Figure 4A), (p = 0.722). In osteoporotic cadavers, there was no difference in the mean cyclic displacement of the unitized constructs (2.46 ± 0.47mm) compared to the non-unitized constructs (2.91 ± 1.49mm) (p =0.639). There was statistically no significant difference in cyclic displacement between the unitized and non-unitized groups in osteoporotic sawbones(p = 0.181). Linked constructs did not demonstrate increased axial stiffness or decreased cyclical displacement in comparison to unlinked constructs in young cadaveric specimens, osteoporotic cadaveric specimens, or osteoporotic sawbones.

Reloading Modulus Estimation Based on Static and Dynamic Plate Load Tests Carried out on Unpaved Forest Roads

Reloading Modulus Estimation Based on Static and Dynamic Plate Load Tests Carried out on Unpaved Forest Roads

Calibrating resistance factors of pile groups based on individual pile proof load tests

Pile load tests have been utilized to reduce the uncertainty of pile resistance, thus leading to a higher resistance factor used in the Load and Resistance Factor Design (LRFD). Previous studies have primarily focused on calibrating resistance factors for single piles based on load tests. This calibration hinges upon the resistance bias factor of single piles, defined as the ratio of measured resistance to predicted resistance. Due to the redundancy in the pile group system, it is conventionally assumed that if the individual piles within the group achieve a lower reliability index (e.g., 2.0–2.5), the pile group as a whole attains the target reliability index of 3. However, the approach is empirical as it does not consider system redundancy directly. Moreover, this empirical approach disregards the correlation between resistance bias factors of individual piles, which is inherently influenced by the spatial variability of soils. In this study, the random finite difference method (RFDM) is employed to evaluate the correlation between resistance bias factors of individual piles in spatially variable soils. The resultant correlation matrix is subsequentially employed in Bayes’ theorem to update resistance bias factors using individual pile load test results and their corresponding test locations. The updated resistance bias factors are then used for the direct calibration of resistance factors for pile groups within the framework of LRFD. A pile group subject to vertical loading in undrained clays is adopted for illustration. Comparative analyses between the proposed approach and the empirical approach demonstrate that the latter tends to overestimate the resistance factor. Furthermore, the proposed approach enables the determination of optimal locations for conducting subsequent load tests based on previous test results.

Rate dependent C* fracture parameter using the optimized wedge-split test geometry and vision-based automated crack tip detection

Typical monotonic load-line displacement (LLD) control and crack mouth opening displacement (CMOD) control cracking tests are limited to singular loading rates and testing temperatures. These experimental protocols are not designed to derive a fundamental fracture parameter capable of relating to the viscoelastic property and cracking behavior of asphalt concrete (AC). On the other hand, a multi-rate LLD-control monotonic fracture experiment is capable of capturing the viscoelastic cracking behavior of AC by providing the rate-dependent fundamental C* fracture parameter as an output. Crack length and crack speed parameters are combined with reaction loads to calculate the rate-dependent C* parameter. The current C* experiment protocol implements manual processing of video images and exhibits high variability. The study aims to optimize the wedge-split geometry and improve the C* fracture parameter calculation protocol by applying an automated vision-based crack detection system and recording the crack growth path, considering the horizontal and vertical movement of the crack tip with higher accuracy. The three notch lengths (5, 15, and 30 mm) were evaluated. Plant and laboratory-produced mixes with varying stiffness and fracture characteristics were included in the testing program. An optimized notch length for the test geometry was determined based on the on-specimen strain field observed using the digital image correlation (DIC) technique and crack path analysis. The optimum notch length was found to be 15 mm due to consistent strain localization at the crack tip and less crack deviation in the horizontal direction. The main contribution of this paper is the proposed vision-based crack path detection method, which enables measuring the crack path's true crack length and maximum horizontal deviation. The developed protocol and optimization of the testing geometry led to a significant improvement of the existing C* testing protocol, resulting in higher data quality and consistent results. The proposed protocol was validated using three comparable and distinctively different lab-produced mixtures. The results show that the C* experiment effectively differentiated between the mixes based on crack speed and the C* parameter.