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Summary Blepharoptosis is a symptom that is commonly observed in clinics. It presents with drooping of the upper eyelid and an asymmetric appearance of the eye. It can occur because of various causes. If left untreated, severe congenital blepharoptosis may impair visual function. The surgical approach largely depends on the severity of blepharoptosis, Bell's phenomenon, and surgical history. However, it is intricate and difficult to achieve satisfactory symmetry and avoid complications. Owing to the complexity involved and discrepancies in treatment, we planned to arrive at a consensus on the diagnosis and correction of blepharoptosis among Chinese plastic surgeons and ophthalmologists, aiming to establish more standardized treatments and cause less harm to patients.

Freeze-thaw (F-T) is an environmental hazard to concrete, severely reducing the mechanical properties and durability of concrete structures. The quantitative calculation of the shear performance of lightweight aggregate concrete (LWAC) after F-T action remains obscure. This study performed comprehensive research on basalt (BF)- and polyacrylonitrile fiber (PANF)-reinforced LWACs after F-T action, which can provide the basis for durability design. Compared with plain LWAC, specimens with fiber reinforcement showed a lower reduction in the relative dynamic elastic modulus (RDEM) and shear strength, and the shear strength and length-diameter rate of the fibers were the main impact factors. From the tests, 1.0% BF and 1.5% PANF are suggested as optimal for F-T resistance enhancement. Corresponding models are proposed to predict the changing tendencies of the shear strength, peak shear strain and shear modulus of LWACs after F-T cycles, considering the impact fibers and the environmental parameters. A statistically stochastic model was applied to predict the shear stress-strain curves after F-T action, and the calculation results match the test results well. The evaluation criteria in the standard are unsafe for LWAC F-T durability design. The F-T service life evaluation based on strength degradation could be advantageous in terms of the sustainable development of LWACs in an F-T environment.

Alkali-activated materials have received considerable attention in regarding their use as environmentally sustainable alternatives to Portland cement. However, the brittleness and shrinkage cracking of these materials have hindered their wider application. An effective solution to these problems is adding fibre to the concrete. This study investigated the mechanical properties of basalt and PP fibre-reinforced alkali-activated slag (AAS) concrete. A total of 11 mixture groups with different fibre dosages and lengths were created, and 132 samples were subjected to cube compressive, prism compressive, splitting tensile, and flexural strength tests. The influence of the fibre dosage and length on the mechanical properties was determined. Owing to the different strength calculation formulas and large shrinkage of the AAS material, significant differences are observed when the tensile strength of AAS concrete is characterized analysed through splitting tensile and flexural strength tests. For the same fibre length and dosage, PP fibre did not improve the strength of AAS concrete as effectively as basalt fibre did. According to the experimental results, a mathematical method was proposed to determine an optimal solution to the bivariate problem.

This paper presents a study on the shear performance of two different high-performance chopped fibers (basalt fiber and polyacrylonitrile fiber) employed to reinforce lightweight aggregate concrete. Environmentally friendly supplementary cementitious materials, fly ash and silica fume, are used to substitute a part of cement. Around 21 UDVW specimens are designed to test shear performance. The relationships between the shear strength and the cube compressive strength, splitting strength, flexural strength, and specific strength are established. Although the addition of the fibers does not change the shear failure morphologies, but could change the development direction of the cracks. Moreover, the fibers increase both the peak shear stress and the peak shear strain, and corresponding calculation models are proposed to predict these properties using the coefficient of shear strength enhancement βs. When the fiber content reaches 1% and 1.5%, the normalized shear stress–strain compared wrapped that of plain specimen notably. With an increase in the fiber content, the peak secant shear modulus decreases slightly, whereas the initial tangent shear modulus increases. Moreover, calculation methods are established to compute the peak secant shear modulus and the initial tangent shear modulus. The calculated results of several equations in this study present excellent agreement with the test results.

The objective of the study is to examine the influence of high sustained loads and longitudinal reinforcement on the long-term deformation of concrete beams. First, the influence of high sustained loads on the creep of reinforced concrete beams was investigated using five beams with load levels (ratio of sustained load to failure load) of 0.3, 0.4, 0.5, 0.6, and 0.7. A load level of 0.3 is the service load for a comparative analysis, and load levels of higher than 0.3 are considered high loads. The influence of the longitudinal reinforcement on the creep of the reinforced concrete beams was then studied using four beams with a ratio of longitudinal reinforcement of 0.81%, 1.55%, 2.14%, and 2.72%, respectively. Furthermore, the influences of the load levels and longitudinal reinforcement on the curvature creep, creep of the concrete at the edge of the compressive zone, and the mid-span deflection creep were analysed. Moreover, a comparison between the test data and the existing calculation model of the deformation of a beam was conducted, and the existing model used to predict the long-term deflection of reinforced concrete beams with high sustained loads within a wide range of longitudinal reinforcement ratios was modified. Finally, post-creep tests of the beams were conducted and the calculated formulas of the total strain (the sum of the initial strain, creep strain, and increased strain after creep) of the concrete at the compression edge of the beams was obtained through a regression analysis.