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To enhance the moisture damage performance of hot mix asphalt (HMA), treating the aggregate surface with a suitable additive was a more convenient approach. In this research, two types of aggregate modifiers were used to study the effect of moisture damage on HMA. Three different aggregate sources were selected based on their abundance of use in HMA. To study the impact of these aggregate modifiers on moisture susceptibility of HMA, the indirect tensile strength test and indirect tensile modulus test were used as the performance tests. Moisture conditioning of specimens was carried out to simulate the effect of moisture on HMA. The prepared samples’ tensile strength ratio (TSR) and stiffness modulus (Sm) results indicated a decrease in the strength of the HMA after moisture conditioning. After treating the aggregate surface with additives, an improvement was seen in dry and wet strength and stiffness. Moreover, an increasing trend was observed for both additives. The correlation between TSR and strength loss reveals a strong correlation (R2 = 0.7219). Also, the two additives indicate increased wettability of asphalt binder over aggregate, thus improving the adhesion between aggregate and asphalt binder.

When amphibious aircraft, ships, and other equipment perform tasks on the water, especially in winter or in low-temperature environments such as high latitudes, high altitudes, and polar regions, they will inevitably encounter icing problems which can adversely affect the safety and performance of these devices. In order to study the mechanical properties of freshwater and seawater ice, this paper tests and analyzes the tensile and shear strengths of static ice and proposes the test principle of shear and tensile strengths of static ice. It then designs and builds the corresponding test equipment, prepares the freshwater and seawater ice samples, and completes the tests. Experiments yield the shear and tensile strengths of freshwater and different seawater samples at various temperatures, and the temperature–strength curves are then drawn. The findings can provide technical support and valuable reference for anti-icing and de-icing design of water vehicles in low-temperature and hostile ocean environments.

This study evaluates the workability and compressive strength properties of normal weight concrete (NWC) using high dosage of fly ash cement replacement. The goal is to find the suitable mix proportion of G40 NWC and to study the slump-loss at different interval time with fly ash replacement up to 60%. The strength properties of NWC were investigated using rebound hammer test as non-destructive and compressive strength test for verifying it. The acceptable mix proportion for fly ash replacement was then investigated using laboratory experiments. For strength properties of NWC, the samples were tested for 3, 7, 14 and 28 days. Results indicate that the inclusion of fly ash as partial cement replacement improves the workability of NWC concrete. The slump-loss of NWC with fly ash increases and it delays the setting time of fresh concrete. The strength of concrete reduces with an increment of fly ash. The strength measured using non-destructive test is lower when compared to compressive strength test. The results demonstrate that the replacement of cement with fly ash in concrete is beneficial and the targeted strength of concrete will achieve with time.

Duchenne muscular dystrophy (DMD) is an X-linked recessive disorder. It is still an incurable disease and many clinical trials are going on to find the cure for this disease. There is a need for sensitive and reliable measures for detecting the disease progression. This manuscript focuses on reviewing the different outcome measures which can be used in the Indian DMD patients.

Scientists and engineers are constantly trying to improve the performance of asphalt mixtures, and a wide range of modifiers are utilised to enhance HMA characteristics against damage such as rutting, aggregate stripping, and cracking. The major objective of this research is to evaluate the performance of flexible pavement using asphalt from the Al-Daurah refinery with two locally additive, hydrated lime and polypropylene. Hot mix asphalt specimens were prepared with aggregate, of nominal maximum size 25 mm (base course) and 19 mm (binder course). Cement is usually utilised as an HMA filler, and a percentage of Portland cement was used in this work, at 5% for the base course and 6% for the binder course. Polypropylene was used as additive with percentages of 1, 2, and 3% by weight of asphalt, and hydrated lime was used in a dry state at a percentage of 1% by weight of aggregate as a part replacer of filler. The main mechanical characteristics of asphalt mixtures were evaluated using the Marshall index of retained strength and indirect tensile strength tests. Using hydrated lime and polypropylene caused the results of Marshall tests and indirect tensile tests to increase by 1.3 and 1.5 times, respectively, compared with the control mixture, while the index of retained strength test increased by 1.3 times compared with the control mixture. In particular, the addition of a combination of 1% hydrated lime by weight of aggregate and 2% polypropylene by weight of asphalt-to-asphalt mixtures satisfied the requirements for stability, moisture sensitivity, and indirect tensile strength.

High permittivity materials are currently in use for mitigation of electrical stress in high-voltage apparatus and energy storage systems. In this work, epoxy-based high permittivity nanocomposites with Barium titanate (BaTiO3) nanofillers are considered, for the purpose of stress mitigation. Uniform dispersion of the fillers in the polymer up to 10% by volume is achieved. Apart from the use of as-received fillers, the effect of using surface-functionalised nanoparticles (with 3-glycidoxypropyltrimethoxy-silane) before use is also investigated. The nanocomposite is characterised in terms of its complex permittivity, DC conductivity, short-term AC breakdown strength and space charge accumulation, to gauge its suitability for use in high-voltage insulation. Complex permittivity is measured using broadband dielectric spectroscopy over a broad frequency range of 1 mHz to 1 MHz. DC conductivity is studied from polarisation–depolarisation current measurements. Short-term AC breakdown strength tests are performed at power frequency (50 Hz). Space charge density along the sample thickness is obtained using pulsed electro-acoustic technique. A computational case-study is presented to show the feasibility of using the high permittivity nanocomposite for electric stress control in high-voltage equipment (viz., at mounting flanges of 69 kV bushings).

The paper deals with the accuracy of measurements of strains (elongation and necking) and stresses (tensile strength) in static room-temperature tensile strength tests. We present methods for calculating measurement errors and uncertainties, and discuss the determination of the limiting errors of the quantities measured for circular and rectangular specimens, which is illustrated with examples.

Carbon fiber-reinforced thermoplastics (CFRTPs) have attracted attention in aerospace because of their superior specific strength and stiffness. It can be assembled by adhesive bonding; however, the existing evaluation of bonding strength is inadequate. For example, in a single-lap shear test, the weld zone fails in a combined stress state because of the bending moment. Therefore, the strength obtained experimentally is only the apparent strength. The true bonding strength was obtained via numerical analysis by outputting the local stress state at the initiation point of failure. In this study, the apparent and true bonding strengths were compared with respect to three types of strength evaluation tests to comprehensively evaluate bonding strength. Consequently, the single-lap shear test underestimates the apparent bonding strength by less than 14% of the true bonding strength. This indicates that care should be taken when determining the adhesion properties for use in numerical analyses based on experimental results. We also discussed the thickness dependence of the adhesive on the stress state and found that the developed shear test by compression reduced the discrepancy between apparent and true strength compared with the single-lap shear test and reduced the thickness dependence compared with the flatwise tensile test.

This research provides useful insights into sustainable and cost-effective pavement rehabilitation by evaluating the combined effects of both Reclaimed Asphalt Pavement (RAP) and Crumb Rubber (CR) modification on flexible pavement performance using actual motorway sections. Pavement rehabilitation and maintenance can enhance the design and serviceable life of the pavement. Additionally, modification of asphalt with Crumb Rubber (CR) and Reclaimed Asphalt Pavement (RAP) not only proves to be economical but can also increase the resistance of flexible pavement concerning rutting, fatigue, and moisture damage. Four different pavement sections were selected, which were rehabilitated and modified with Reclaimed Asphalt Pavement (RAP), Crumb Rubber (CR), and a combination of both, along the Islamabad-Lahore motorway (M-2), Pakistan. The first pavement section consists of Asphalt Concrete Wearing Course (ACWC) with 60/70 grade bitumen as a binder (RAP 0%, CR 0%), the second pavement section was a mixture of asphalt concrete with crumb rubber modified bitumen as a binder (RAP0%, CR7%), the third pavement section was a blend of 15% RAP with 60/70 grade bitumen as a binder (RAP15%, CR 0%), the fourth section was a mixture of 15% RAP and 7% crumb rubber modified bitumen (RAP 15%, CR 7%). Pavement cores were extracted from the selected four pavement sections, which were experimentally explored in the laboratory to find the impact on the performance of highway pavement employing Reclaimed Asphalt Pavement (RAP) and Crumb Rubber (CR), partially replacing bituminous binder in the asphalt. The results show notable improvements in rutting resistance, tensile strength, and resilience. It was concluded that the performance of the section employing either RAP, CR or combined RAP and CR modified bitumen better enhanced the performance of pavement in terms of rut depth, indirect tensile strength and modulus of resilience. For instance, rutting depth was reduced by 41.35% and indirect tensile strength of pavement was increased by 17.93% by employing 15% RAP and 7% CR in modified bitumen binder for asphaltic mix. Likewise, the modulus of resilience was increased by 38.23% for the section employing 15% RAP and 7% CR in pavement.

The point load strength test index (Is(50)) rapidly determines the tensile strength and the uniaxial compressive strength of rocks. It is necessary to analyze the power index (m) of Is(50) when conducting a point load test (PLT) on irregular rock blocks. In this study, sandy dolomites from the Sinian Dengying Formation (Zbdn) and Doushantuo Formation (Zbd) in the Yuxi section of the Central Yunnan Water Diversion Project were analyzed for their physical and mechanical properties. PLTs were performed on dolomites with different geological origins and weathering degrees, and the m-values were determined through statistical methods and regression analysis. The results showed that the logP–logDe2 curve exhibits a negative slope, and the m-value and its correlation coefficient (R2) increased with the decreasing weathering degree. For similar weathering conditions, the R2 of the Zbdn dolomites was higher than that of the Zbd dolomites. The error analysis indicated that the obtained m-values were highly accurate for the dolomite with different geological origins and weathering degrees. Casting slice identification tests further confirmed that the dolomite pore structure and density, connectedness, and specific mineral composition were the primary factors influencing the m-value.HighlightsThis is the first study on the power index (m) of sandy dolomites.The logP–logDe2 curve exhibits a negative slope, and m-value and its R2 increase with decreasing weathering degree.Pore structure and density, connectedness, and specific mineral composition primarily influence the m-value.For a similar weathering degree, the R2 of Zbdn dolomites was higher than that of Zbd dolomites.