Test Specimens Research Articles

Impact of saline irrigation on the early mechanical characteristics and microstructure of bone cement

Very high heat is generated during the polymerization of poly (methyl methacrylate) (PMMA) bone cement, which is used for implant fixation in orthopedic surgery. As such, it has been suggested that irrigating the bone cement layer in the surgical site with a saline solution is a way of cooling the layer. In this study, we aimed to determine the influence of irrigation with a saline solution on the flexural strength and the microstructure of the test specimens of two PMMA bone cement brands: Simplex P and FIX 1. Specimens were assigned to three groups: (1) irrigation with normal saline solution at 25 °C (RS group), (2) irrigation with cold saline at 4 °C (CS group), and (3) no irrigation (control group). For each of the groups, the specimens were tested after various times of aging in phosphate-buffered saline solution (PBS) at 37 °C for 1 h, 24 h, and 7 days. Flexural strength was measured following ISO 5833 protocol, and the surface microstructure was determined using scanning electron microscopy (SEM). The flexural strength results showed that for each of the cement brands, the difference between the groups was not significant, except for Simplex P specimens aged for 24 h, for which flexural strength of the RS and CS group specimens was lower than in the control group. The microstructural features of the surface of the specimens were similar across groups. These findings suggest that in a cemented arthroplasty, irrigation of the bone cement for the purpose of cooling it must only be used after very careful consideration.

Fatigue Behaviour of PA66 GF30 at Different Temperatures.

A comprehensive experimental investigation to understand the mechanical properties and fatigue behaviour of glass-reinforced polyamide (PA66 GF30) at different temperatures is presented in this paper. The specimens for quasi-static and fatigue testing were machined from previously extruded plates, where two orientations were considered: (i) the extrusion direction (ED) and (ii) the direction perpendicular to extrusion (PED). Both the quasi-static and fatigue tests were performed under different temperatures (22 °C and 100 °C). The fatigue tests were performed in a load control regime under pulsating loading (R = 0.1) to create S-N curves for all the temperatures and loading directions. The experimental results of the quasi-static tests showed that the test specimens manufactured in the extrusion direction have better mechanical properties when compared to those of the specimens manufactured perpendicular to the extrusion direction. Furthermore, the analysis of the quasi-static tensile test results showed that tensile strength, yield strength, and the modulus of elasticity are significantly dependent on the temperature and deteriorate when the temperature is increased from 22 °C to 100 °C. The results of the fatigue tests showed that at both the temperatures (22 °C and 100 °C), the samples produced in the direction of extrusion exhibited higher fatigue strength than those produced perpendicular to the direction of extrusion. For all the sample orientations, the fatigue strength decreased significantly with increasing temperature. The obtained experimental results could be very useful when designing and dimensioning different dynamically loaded engineering components made of PA66 GF30 subjected to high temperatures.

Study of the mechanical and tribological behaviour of a low-alloy steel treated by nitriding

This study investigates the effects of plasma nitriding treatment on the mechanical surface properties of 25Cr2Ni4W low alloy steel, using Charpy test specimens. Plasma nitriding is a surface modification process that introduces nitrogen into the steel, enhancing its hardness and wear resistance. The experimental setup involved a comparative analysis of treated and untreated specimens to evaluate the impact of the nitriding process on the material’s mechanical performance.Optical microscopy (OM) analysis of the nitrided specimen revealed the formation of a nitride zone at the surface, confirming successful nitrogen implantation. The Charpy impact test showed that the treated specimen required 72.8 Joules of energy to fracture, a significant increase of 10.3 Joules compared to the untreated specimen, which required only 62.5 Joules. This indicates that plasma nitriding improved the material’s toughness and resistance to crack propagation. Additionally, the nitriding process led to an increase in nano-hardness, as measured using nanoindentation techniques. The treated specimen exhibited a higher surface hardness compared to the untreated sample, further enhancing its wear resistance and durability. These results suggest that plasma nitriding effectively improves both the hardness and toughness of 25Cr2Ni4W low alloy steel, making it a promising treatment for applications requiring enhanced mechanical performance, particularly in high-stress environments.

UTILIZATION AND EFFECT OF SPECIMEN SHAPE AND SIZE ON THE STRENGTH PROPERTIES OF CONCRETE

High strength concrete is currently a common construction material and its compressive strength is most basic and important material property in structural design. In this paper, we investigate the influence of the shape and of the size of the specimens on the compressive strength of high-strength concrete. We used cylinder sand cubes of different sizes for performingd stable stress-strain tests. This value was kept constant throughout the experimental program. Our results show that the post- peak behavior of the cubes is milder than that of the cylinders, which results in a strong energy consumption after the peak. This is constant with the observation of the crack pattern: the extent of micro-cracking throughout the specimen is denser in the cubes than in the cylinders. Indeed, a main inclined fracture surface is nucleated in cylinders, whereas in cubes we find that lateral sides get spalled and that there is a dense columnar cracking in the bulk of the specimen. Finally, we investigate the relationship between the compressive strength given by both types of specimen for several specimen sizes. The influence of specimen size and shape on the measured compressive strength was investigated for different high strength concrete mixes. Also the compressive strength can also be determined to be in significantly affected by changing l/d as the strength of concrete increases. After testing of specimens at 7and 28 days, the results show that the cube specimen is generally stronger than the cylinder specimen and this effect will be gradually decreased when the concrete strength increased. For the effect of the specimen size the results show that the compressive strength increases as the specimen size decreases. This size effect might be ignored as the relationships showed that the effect is relatively small as compared to specimen shape effect.

Postmortem genetic diagnosis of hereditary leiomyomatosis and renal cell carcinoma syndrome: Identification through normal kidney tissues after surgical removal

IntroductionHereditary leiomyomatosis and renal cell cancer is an autosomal dominant disorder caused by germline mutations in the FH gene and is associated with poor prognosis of aggressive renal cancer.Case presentationA 33‐year‐old man presented with asymptomatic gross hematuria and was diagnosed with a right renal tumor, cT3aN1M0. He underwent open radical nephrectomy, and pathological examination revealed papillary renal cell carcinoma. Despite aggressive treatment, the disease progressed rapidly, and discussions regarding genetic testing could not take place during his lifetime, although circulating‐tumor DNA showed mutation of FH gene. After death, his wife requested postmortem genetic testing. Genetic analysis using DNA extracted from normal kidney tissues in surgical specimens (blood sample absence) confirmed the FH mutation, and hereditary leiomyomatosis and renal cell cancer was diagnosed posthumously.ConclusionThis highlights the utility of postmortem genetic testing of surgical specimens to diagnose hereditary leiomyomatosis and renal cell cancer and provide genetic counseling to families, despite limitations during the patient's life.

Polyurethane foam sandwich structures collapse modes under three-point bending

The aim of this analysis is to investigate the mechanical behavior of polyurethane foam sandwich sandwiches in three-point bending tests by varying the span length of test specimens and the core thickness. Theoretical models are represented that use foamed sandwich mechanics and classical beam theory. Tests were dispensed so as to seek out the link between the geometrical configuration of the sandwich and therefore the failure mechanism. The static bending tests created numerous collapse modes looking on support span distance and core layer thickness. Numerous failure modes and injury as well as indentation failure below the loading roller, core–upper skin delamination and core shear square measure reportable and mentioned the consequences of core thickness and span length on most static load and bending stiffness also are examined. it absolutely was ascertained that the span distance has important impact on the failure mode of the specimen.

Effect of surface condition on fatigue life of 7075 aluminium alloy

ABSTRACT This study investigates the effects of surface treatments on the mechanical properties of 4 mm thick flat test specimens made from annealed AA 7075 alloy in three conditions: as-received, shot-peened, and electropolished. Experimental investigations, including cyclic stress response, fatigue life, microstructural observations, and mechanical properties, are conducted to provide insights into the fatigue behaviour of the alloy. The surface roughness (Ra) values were measured at 546 nm for as-received, 830 nm for shot-peened, and 72 nm for electropolished samples. Push–pull fatigue tests conducted at a stress amplitude of 500 MPa with a load ratio (R) of -1 yielded average fatigue lives of 1200 cycles for as-received, 990 cycles for shot-peened, and 2700 cycles for electropolished samples. These results align with the general observation that smoother surfaces yield better fatigue life, which can be explained by the influence of surface conditions on stress–strain behaviour, microstructure, and fracture mechanisms. The smoother surfaces have lower stress concentration points, so the propensity for crack nucleation and propagation is lower in these samples, leading to improved mechanical properties.

Corrosion Performance of Steel Bar Embedded in Seawater Mixed Mortar with Batching Plant Waste

Reinforcing steel deterioration is complicated by corrosion. Reinforcing steel corrosion can weaken a structure. Corrosion cannot be eliminated; however, it can be reduced to increase building service life. The objective of the research it to demonstrate the effect of coating method as corrosion prevention and the cover depth to the corrosion performance of steel bar embedded in seawater mixed mortar. This study examines the corrosion rate of steel reinforcement in a 15 x 15 x 15 cm mortar cube made by using seawater as mixing water and containing Portland Pozzolan Cement (PPC) as a binder material. This study also experiences numerous corrosion mitigation methods using wet, dry, and dry-wet cycle exposure methods. The reinforcement and mortar surface were protected with anti-corrosive paint. Additionally, specimens without protective measures were also fabricated for comparison. Two reinforcing steels were attached in the two different cover depths, 3 cm and 5 cm. This study used sand and batching plant byproducts as fine aggregate. Study found a hierarchy of corrosion-causing exposures. The dry-wet cycle was the most corrosive, followed by wet and dry. Steel coating prevents corrosion better than surface coating. However, both methods outperformed the uncoated method in corrosion resistance. The mortar cover was 5 cm thick, compared to 3 cm expected. A combination of mortar with fine sand aggregate outperformed dry mortar made from batching plant leftovers. The investigation of corrosion potential through the utilization of the half-cell potential technique reveals that the outcomes obtained from test specimens using the steel coating prevention approach exhibit a higher degree of positivity in comparison to the prevention method including surface coating. The unprotected approach exhibits outcomes that lean towards being more unfavorable compared to the steel coating prevention method and the surface coating prevention method. The findings indicate that the performance of reinforcing steel embedded within a 3 cm mortar cover depth is often worse when compared to reinforcing steel situated inside a 5 cm mortar cover depth.

ENHANCING THE DAMPING BEHAVIOUR OF STEEL CRANE STRUC-TURES BY INTRODUCING A CONCRETE CORE

The potential use of steel tube confined concrete columns in crane structures is being explored as a means of enhancing damping during the movement of carrying and lifting machines. This is with a view to mitigating the impact of dynamic effects that may arise during operation. The results of experimental studies of tube confined concrete specimens for stability under central compression by static loading are given. This paper presents a methodology for dynamic tests of specimens, which is used to determine the damping ratio of vibrations and the inelastic resistance coefficient of composite materials. The results demonstrate that tube confined concrete specimens possess enhanced damping behaviour in comparison to steel and reinforced concrete structures. This observation suggests that they are an effective solution for load-bearing structures designed to support moving overhead cranes.

Cost-Effective Laser Powder Bed Fusion of Ti-6Al-4V Grade 5: The Effect of Expanding Powder Size Distribution on Mechanical Performance

This study aims to assess the feasibility of expanding the powder size distribution (PSD) of Ti-6Al-4V grade 5 powder for LPBF to achieve cost reduction. Parameter optimization to minimize the degradation of mechanical properties due to the expanded particle size distribution was conducted. Mechanical tests for specimens built using optimized parameters revealed minor reductions in strength: 3.9% in tensile yield strength, 1.1% in compressive strength, 5.5% in shear strength, and 4.5% in bearing yield strength—all of which complied with MMPDS standards. Statistical analysis, using the Anderson–Darling test, demonstrated stable mechanical performance and minimal variation between the original and expanded PSDs. These results highlight the potential of an expanded PSD to achieve cost reductions while maintaining compliance with industry standards, offering a practical solution for LPBF applications in cost-sensitive and high-performance industries.

Durability of Wood-Cement Composites with Modified Composition by Limestone and Stabilised Spruce Chips.

Limestone (LS) and stabilised secondary spruce chips (SCs) utilisation in wood-cement composites is still an unexplored area. Therefore, the main objective of the research presented here is the assessment of the long-term behaviour of cement-bonded particleboards (CBPs) modified by LS and SCs. Cement (CE) was replaced by 10% of LS, and spruce chips by 7% of SCs. The test specimens were stored in a laboratory and exterior environment (Middle Europe) for up to 2 years. The density, strength, and modulus of elasticity were evaluated after 28 days, and then in 6-month periods. The hygroscopicity was analysed separately. The mineralogical composition and microstructure were analysed due to possible LS participation during hydration. SC synergic behaviour in CBPs was also studied. After 2 years, the microstructure of the CBP was more compact, and denser. Strong carbonatation contributes to the improvement of CBP properties. The products of carbonatation were present in both the matrix and wood chips. The hydration of the matrix was almost finished. LS has a positive effect on the matrix microstructure development. LS acts both as an active component participating in the formation of the cement matrix structure and as an inert microfiller, synergic with hydration products. SCs have a positive effect on the hygroscopic behaviour of CBPs and slightly negative effect on the tensile strength.

The Effect of Elastomer Content and Annealing on the Physical Properties of Upcycled Polyethylene Terephthalate-Maleated Styrene Ethylene Butylene Styrene Blends for Additive Manufacturing.

In the work presented here, we explore the upcycling of polyethylene terephthalate (PET) that was derived from water bottles. The material was granulated and extruded into a filament compatible with fused filament fabrication (FFF) additive manufacturing platforms. Three iterations of PET combined with a thermoplastic elastomer, styrene ethylene butylene styrene with a maleic anhydride graft (SEBS-g-MA), were made with 5, 10, and 20% by mass elastomer content. The elastomer and specific mass percentages were chosen based on prior successes involving acrylonitrile butadiene styrene (ABS), in which the maleic anhydride graft enabled compatibility between different materials. The rheological properties of PET and the PET/SEBS blends were characterized by the melt flow index and dynamic mechanical analysis. The addition of SEBS-g-MA did not have a significant impact on mechanical properties, as determined by tensile and impact testing, where all test specimens were manufactured by FFF. Delamination of the tensile specimens convoluted the ability to discern differences in the mechanical properties, particularly % elongation. Annealing of the specimens enabled the observation of the effect of elastomer content on the mechanical properties, particularly in the case of impact testing, where the impact strength increased with the increase in SEBS content. However, annealing led to shrinkage of the specimens, detracting from the realized benefits of the thermal process. Scanning electron microscopy of spent tensile specimens revealed that, in the non-annealed condition, SEBS formed nodules that would detach from the PET matrix during the tensile test, indicating that a robust bond was not present. The addition of SEBS-g-MA did allow for shape memory property characterization, where deformation of tensile specimens occurred at room temperature. Specimens from the 20% by mass elastomer content sample group exhibited a shape fixation ratio on the order of 99% and a shape recovery ratio on the order of 80%. This work demonstrates a potential waste reduction strategy to tackle the problem of polymer waste by upcycling discarded plastic into a feedstock material for additive manufacturing with shape memory properties.

Edge Chipping Resistance and Flexural Strength of CAD-CAM Ceramics Before and After Thermomechanical Aging.

To evaluate the complementary mechanical properties of dental ceramics using edge chipping resistance (Rea) and flexural strength before and after thermomechanical aging. Computer-aided design and computer-aided manufacturing of ceramic materials, including zirconia (ZR), lithium disilicate (LS2), and resin nanoceramics (RNC), were evaluated. Specimens for flexural strength testing were fabricated with dimensions of 3 × 4 × 25 mm, with 30 specimens per group. For the edge chipping test (ECT), specimens were fabricated with dimensions of 3 × 4 × 12 mm, with 48 specimens per group. Half of the specimens for both tests were subjected to thermomechanical aging for 200,000 cycles at 50 N. A Weibull analysis was performed to determine flexural strength. Fractographic analysis was performed before and after thermomechanical aging during the ECT. X-ray diffractometry (XRD) was performed on the ZR specimens before and after thermomechanical aging. Flexural strength was analyzed using a two-way repeated analysis of variance (ANOVA) with a t-test, and Rea was analyzed using Pearson correlation and a two-way repeated ANOVA. The flexural strength and Rea differed according to the material (p = 0.001), whereas they were similar before and after thermomechanical aging (p > 0.05). The Weibull modulus of the flexural strength decreased after thermomechanical aging. In the fractographic analysis of the ECT, more than two fracture origins were identified after thermomechanical aging. The XRD analysis of ZR showed an increased monoclinic phase after thermomechanical aging. All the materials met the ISO 6872 standards for bending test. However, LS2 and RNC show low edge chipping resistance within the range of the occlusal force. The thermomechanical aging did not significantly alter the mechanical properties of the materials. However, the Weibull coefficients of the flexural strength decreased, and an additional origin of fracture appeared after thermomechanical aging. Flexural strength and Rea differed depending on the material used. The probability of the material fracture increased after thermomechanical aging. To understand ceramic fractures, two mechanical tests and thermomechanical aging must be performed together.

Strain Rate Sensitivity of Low Carbon Threaded Steel Rods of Grade 4.6.

Bolt connections are widely used in construction and engineering to securely join structural elements. These connections are essential for distributing loads across components and ensuring that structures can withstand external forces. The planned failure of these bolts is of great importance in steel safety barriers (SSBs), as it can directly influence the height of the guardrail and the working width of the SSB during the vehicle impact, which consequently affects the crash consequences. Therefore, it is of great importance to determine the bolt response until fractures under different strain rates. For that purpose, experimental tensile tests of low-strength steel rods of grade 4.6 were conducted at various strain rates (0.0025-25 s-1) until fracture. Test specimens were photographed during the testing, and by means of image processing, input data for calculation of true stresses and strains up to the point of fracture were extracted. Based on the experimental data, material parameters were determined for the Cowper-Symonds model, enabling precise numerical simulations of these connections at various strain rates. A validation study was also performed successfully.

Mechanical Properties and Degree of Conversion of a Novel 3D-Printing Model Resin.

The aim of this study was to evaluate the mechanical properties and degree of conversion of a novel 3D-printing model resin and compare it to eight commercially available model resins. An experimental resin formulated by our proprietary resin technology along with DentaModel, NextDent 2, KeyModel Ultra, Rodin Model, Die and Model 2, DMR III, LCD Grey, and Grey Resin were used in this study. Parallelepiped specimens (2 × 2 × 25 mm, n = 5) were printed and measured for their flexural strength (FS), flexural modulus (FM), and modulus of resilience (MR) in accordance with ISO-4049. Dumbbell-shaped specimens (Type V, n = 5) were printed to test tensile strength (TS) and elongation according to ASTM-D638. Barcol hardness (BH) was measured based on ASTM D2583 using broken tensile strength specimens. Izod-type test specimens (3.2 × 12.7 × 63.5 mm, n = 10) were printed, notched, and determined for impact strength according to ASTM D256-10. The degree of conversion was measured using FTIR (n = 5). Data were analyzed using one-way ANOVA and post hoc Tukey tests (p ≤ 0.05). The experimental resin exhibited a similar or significantly greater flexural strength (88.8 MPa), modulus of resilience (2.13 MPa), tensile strength (54.4 MPa), and hardness (82.9) than most model resins (FS 62.6-90.1 MPa, MR 1.37-2.0 MPa, TS 36.3-54.6 MPa, BH 66.1-83.7). The elongation (6.2%) and impact strength (14.2 J/m) of the experimental resin are statistically the same as those of most resins (3.0-7.5%, 13.8-16.4 J/m). However, the experimental resin has a significantly lower flexural modulus (1.97 GPa) than most resins (2.18-3.03 GPa). The experimental resin exhibited a significantly higher degree of conversion (66.58%) than most resins (1.11-62.34%) for 40 s of light curing; however, a similar or higher value (84.87%) than most resins (72.27-82.51%) was obtained for 3D-printed objects. The newly formulated 3D-printing model resin exhibited adequate mechanical properties and degree of conversion, which is comparable to the commercially available 3D-printing model resin materials. The new 3D-printing model resin can be used for modeling applications in restoration, orthodontics, implants, and other cases.

Performance of Ultrasensitive Polymerase Chain Reaction Testing for JC Polyomavirus in Cerebrospinal Fluid Compared with Pathological Diagnosis of Progressive Multifocal Leukoencephalopathy.

Progressive multifocal leukoencephalopathy (PML) is a demyelinating disease caused by the JC polyomavirus (JCPyV). Based on the clinical criteria, PML is diagnosed via polymerase chain reaction (PCR) detection of JCPyV DNA in cerebrospinal fluid (CSF) in combination with neurological and imaging findings. Although the utility of CSF JCPyV testing using ultrasensitive PCR assays has been suggested, its potential requires further evaluation. This study retrospectively analyzed the detection performance of ultrasensitive PCR for CSF JCPyV in patients who underwent brain tissue examination based on the pathological diagnostic criteria for PML. Of the 110 patients with pathologically confirmed definite PML or not PML, standard and ultrasensitive CSF testing was performed for 36 and 74 patients, respectively. The sensitivity of ultrasensitive CSF JCPyV testing of the initial specimens was 85%. With the addition of the follow-up testing, this figure increased to 95%. The specificity and false-positive rate of ultrasensitive CSF JCPyV testing, including follow-up, were 100% and 0%, respectively. No statistically significant correlation was observed between CSF and brain JCPyV levels. The results of this study demonstrate the high sensitivity and accuracy of ultrasensitive CSF JCPyV testing and provide essential information for the clinical diagnosis of PML.

Testing stored control-arm specimens could dramatically increase statistical power yet reduce costs in cancer screening trials.

Testing stored control-arm specimens could dramatically increase statistical power yet reduce costs in cancer screening trials.

A critical multi-parameter analysis of the densification process on the dimensional stability and bending performance of densified timber

Timber densification is a process wherein various parameters can affect the physical and mechanical properties of the final product. Therefore, it is vital to understand the effects of these parameters to fully exploit the benefits of densification such as improved density, stiffness, and strength. The purpose of this study is to improve on the mechanical properties of Radiata pine (Pinus radiata) and to determine the influence of the process parameters. The densification process and the bending properties of the densified timber were investigated using a fractional factorial experimental design to determine the influence of various parameters (compression ratio, moisture content, compression temperature, heating time, setting temperature, and setting time) on the final product. Among the six process parameters, the compression ratio was the most significant factor with respect to bending properties of the densified timber, while the effect of the other parameters does not show a specific trend with respect to the load–displacement behaviour of the test specimens. A predictive model has been proposed herein to determine the properties of densified timber based on a reduced number of process parameters, with examples based on different design applications.

Assessment of Dielectric Strength for 3D Printed Solid Materials in Terms of Insulation Coordination

Insulating materials can be classified into solid, liquid, and gaseous forms. Solid insulation materials are divided into different types such as organic, inorganic, and polymer types. In electrical circuits, solid insulation materials are generally used as components that provide insulation and mechanical support. In recent years, as a result of developing technologies, the production of participation insulation materials with 3D printing technology has become widespread. Three-dimensional printing technology enables the rapid creation of objects by combining materials based on digital model data. It is important to evaluate the materials produced with 3D printing in terms of insulation coordination. Studies have shown that the electrical breakdown strength of solid dielectrics varies depending on factors such as sample type, thickness, the magnitude of applied voltage, and the temperature of the physical environment. According to IEC-60243 standards, there are various methods to measure the breakdown strength of solid insulators applied to different voltage types. In this study, the behavior of PLA, ABS, ASA, PETG, and PC/ABS materials produced with 3D printing and having the potential to be used as insulation materials when exposed to high voltage within the scope of insulation coordination was investigated. The breakdown strengths of solid insulation materials produced with 3D printing were measured in the high-voltage laboratory within the scope of IEC-60243. Breakdown strength was statistically evaluated with the Weibull distribution. Damage analysis of the breakdowns in the test specimens was examined in detail with ImageJ software. With the comparative analysis, the behaviors of PLA, ABS, ASA, PETG, and PC/ABS solid insulation materials were revealed and their superiority over each other was determined.

Evaluating long-term thermal and chemical stability and leaching potential of low-temperature phase change materials in concrete slabs exposed to outdoor environmental conditions

This study examined the potential of using phase change material (PCM)-integrated concrete slabs for long-term thermal-responsive applications in an outdoor environment condition. The objectives were to: (i) evaluate long-term thermal response, snow melting and freeze–thaw reduction efficiency of PCM integrated concrete slabs, (ii) characterize the chemical stability of PCM in cement matrix, and (ii) assess the possibility of PCM leaching into the cement matrix and subgrade soil of the slabs. The experimental program included: (i) outdoor experimentation using large-scale field concrete slabs, (ii) guarded calorimetric (LGCC) tests of cut-bar concrete specimens, (iii) Fourier transform infrared (FTIR) spectroscopic characterization of PCM in mortar and subgrade soil specimens, and (iv) low-temperature differential scanning calorimetric (LT-DSC) tests to assess and quantify the amount of PCM contamination in subgrade soil. Results presented varying degrees of effectiveness after three years of environmental exposure: Micro-encapsulated PCM (MPCM) concrete exhibited considerable success (i.e., ~ 50%) in snow melting while PCM infused in lightweight aggregates (PCM-LWA) concrete failed to provide substantial snow-melting; moreover, both PCM-LWA and MPCM slabs showed diminished resistance to freeze–thaw (F-T) cycles compared to the first-year winter cycle data. Factors contributing to efficiency loss are found to be shell degradation of microcapsules, potential leaching of PCM into subgrade soil (i.e., between 0.2 to 0.3% wt. concentration), and effects of warm temperatures influencing the degree of evaporation, as evidenced with LGCC, FTIR and LT-DSC results. Strategies to enhance efficiency and stability include improved encapsulation techniques, and vascularization methods.