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Fiber reinforced polymer (FRP) bars have become increasingly popular, while the studies on durability of FRP bars are primarily on small-diameter FRP bars. This study investigated the tensile strength retention in glass FRP (GFRP) bars of different diameters (13 mm and 25 mm) after immersion in an alkaline solution (pH=12.6) at various temperatures (20 °C, 40 °C and 60 °C) for 1, 2, 3, and 6 months. The results reveal that the degradation of GFRP bars was slow at 20 °C, accelerated but not pronounced at 40 °C and considerable at 60 °C. Particularly, the 13 mm diameter GFRP bars exhibited a more significant reduction in tensile strength, with a decrease of 20.12 % after 6 months, while the 25 mm diameter bars only decreased by 13.23 %. Results reveal that, importantly, degradation of GFRP bars is primarily attributed to the diffusion of the moisture and alkalis, which disrupts the bond between the fibers and the matrix, causing interface damage. Finally, based on the Arrhenius theory, it is predicted that the tensile strength retention of 13 mm and 25 mm diameter GFRP bars will be 66.4 % and 79.8 %, respectively, after 50 years of exposure at an average annual temperature of 35 °C. The important finding that the small-diameter FRP bars are more vulnerable to the alkaline exposure than larger diameter bars suggests that the current studies on durability of FRP bars are conservative to be referred in practice.

There has been significant attention from both academics and industries towards the demand for high-strength and crack-free cementitious composites. Nanofibers are a group of promising reinforcement materials due to their high strength, large specific surface area, and high toughness. This paper provides a review of the fracture properties of nanofiber reinforced cement-based composite (NFRC), including the investigation of various types of nanofibers available in the market, test methods, and theoretical analysis models. The effects of different volumes and types of nanofibers are also summarised. Based on the analysis of previous studies, the enhancements in fracture properties are closely associated with the length and aspect ratio of nanofibers. Moreover, several challenges persist in the practical application of NFRC in industries are discussed. Further research efforts are required to address these concerns and advance the industrial application of NFRC.

Idiopathic pulmonary arterial hypertension (IPAH) is a rare disease, with an estimated 500–1000 new cases diagnosed every year. A portion of these cases may be caused by mutations in the BMPR2 gene, suggesting a possible genetic component in the development of the disease. Here, we report two human induced pluripotent stem cell (iPSC) lines generated from IPAH patients. Both cell lines provide valuable insight into the molecular and cellular mechanisms of IPAH and can be used to further understand the disease.

Many concrete columns exhibit a decline in structural performance due to construction inaccuracy, increased load demand and corrosive environment. It is urgent to adopt necessary strengthening methods to improve the mechanical behavior of pre-damaged columns. This paper presents a numerical investigation on the compressive behavior of pre-damaged concrete columns strengthened with a composite jacket of basalt fiber textile and engineered cementitious composites (ECC). After verification of the developed FE model, the failure mechanism of the pre-damaged concrete columns strengthened with TRE (textile-reinforced ECC) under axial compression was evaluated. Furthermore, a parameter analysis was performed to address the effects of thickness of ECC layer, spacing of fiber textile and concrete core strength on the axial behaviour of the pre-damaged columns strengthened with TRE. The results showed that the reinforced columns with different pre-damage levels showed ductile failure characteristics, which was due to a good binding force provided by the textile-ECC composite reinforcement layer. The axial stiffness, ultimate compressive load, and deformation capacity of the strengthened pre-damaged columns decreased with the increasing pre-damage level. The compressive behaviour of confined pre-damaged columns could be improved by increasing thickness of ECC, reducing the spacing of textile, and decreasing strength of the core concrete, especially for the major pre-damaged column.

Tyre-encased-soil elements (TESEs) are segmental units made by compacting soil inside the cavity of EOL tyres. The TESEs can function similarly to bricks to build masonry walls or other load-bearing structures. Tyre walls built of TESEs have proven successful architectural and structural performance. However, the mechanical properties of TESEs have not been scientifically investigated in the past, and insufficient evidence restricted TESEs’ further application as structural components. This project attempted to fill the gap by studying the performance of TESEs subject to axial compressive loads through both laboratory experiments and analytical analysis. Soils with different properties were used in the experiments to quantify their influence on the TESEs performance. It was found that within the range of loading applied in this study, no abrupt failure was observed on the tested TESEs. The axial stress-strain relationship followed an exponential form, possibly due to the strain-hardening effect brought in by the densification of encased soil and increased confinement support from the tyre reinforcement. The encased soil’s density had a significant influence on the load-deformation behaviour of the TESEs. However, the load-carrying capacities were not highly sensitive to the soil type and its moisture content. An analytical model was proposed for capturing the axial and radial strain of TESEs under applied axial loads with a reasonable accuracy. In material characterisation, the strength of EOL tyres captured in the inflation tests were significantly larger than those obtained from direct tensile tests, which revealed the cut tyre strip could not capture the synergic effect of the embedded tyre reinforcement composites in a representative manner. The results of this study can be used by built environment professionals to design and analyse the performance of tyre encased soil and tyre walls.

Expanded vermiculite (EV) is an innovative alternative to conventional fire-resistance material due to exceptional thermal performance and non-combustible property. In this study, the effect of elevated temperatures on microstructure, mechanical and physical properties of foam concrete containing EV as lightweight aggregates (LWA) was investigated. Foam concrete samples with 10%, 15% and 20% EV as sand replacement were developed and exposed to 300 ℃, 600 ℃, and 900 ℃. Scanning electron microscopy (SEM) test was conducted to identify microstructure changes in the cement matrix and fine aggregates after elevated-temperature exposure. The enhanced close-fitted bond in the interfacial transition zone (ITZ) of EV-based foam concrete was observed in SEM, which might be due to the higher water absorption of EV granules. Residual compressive and flexural strength, relative porosity and water sorptivity coefficient of foam concrete were also obtained. The 15% EV reduced compressive strength loss of samples by 1.84%, 11.68% and 69.1% at 300 ℃, 600 ℃ and 900 ℃, respectively, compared with that of the reference as 9.81%, 33.7%, and 72.28%, respectively. Enhanced sorptivity-related durability and lower residual porosity were also obtained at elevated temperatures when 15% EV was added.

Fibre reinforced polymer (FRP) composites have attracted significant attention in repairing existing and deteriorating structures since the traditional rehabilitation techniques have several limitations in terms of durability, self-weight and complex installation process. Prefabricated FRP composite jackets are the preferred solution in repairing bridge piles located both underwater and above the waterline as they can be easily placed around the damaged pile to form a robust single-piece repair system. The structural continuity of the jacket in such a repair system is critical for effectively utilising its maximum strength. This study presents an extensive review of the current practices and new opportunities for using prefabricated composite jackets for structural repair. Important design considerations to effectively utilise prefabricated FRP composite jackets in repairing structures are presented and analysed. The review also identifies the challenges and highlights the future directions of research to increase the acceptance and use of emerging composite repair systems.

LMNA-related dilated cardiomyopathy (LMNA-DCM) is caused by pathogenic variants in the LMNA gene and is characterized by left ventricular chamber enlargement, reduced systolic function, and arrhythmia. Here, we generated three human induced pluripotent stem cell (iPSC) lines from peripheral blood mononuclear cells (PBMCs) of three DCM patients carrying the same single heterozygous mutation, c.398 G > A, in LMNA. All lines exhibited normal iPSC morphology, expressed high levels of pluripotency markers, showed normal karyotypes, and could differentiate into the three germ layers. These patient-specific iPSC lines can serve as invaluable tools to model in vitro pathological mechanisms of LMNA-DCM.

In this study, microwave radiation pre-treatment (MRP) of three recycled plastic aggregates, namely; Polyethylene Terephthalate (PET), High-Density Polyethylene (HDPE) and Polypropylene (PP), was carried out to enhance the bond strength between the plastic aggregates and the concrete matrix. Five concrete mixes were prepared, which included treated and untreated PET plastic aggregate, treated and untreated mixed plastic type aggregates and a control mix without any plastic. The replacement was 15% by volume as a partial replacement of coarse aggregate for all mixes. The modification of plastic surface was assessed before and after the microwave treatment by measuring the contact angle of a water droplet and using SEM images. The engineering characterizations of the concrete incorporating microwave treated recycled plastic aggregates were assessed through investigating physical and mechanical properties as well as water absorption. The results demonstrated that the Interfacial Transition Zone (ITZ) was improved due to PET plastic surface treatment, leading to an improvement in the strength of concrete. No improvement was seen in the strength of concrete that included treated mixed plastic types. Scanning electron microscopy (SEM) images of the treated plastic surface illustrated more roughness in the treated PET plastic surface, while the images of ITZ showed an improvement in the adhesion between the plastic and the cement paste. Despite the unexpected results of the treated mixed recycled plastic, the positive strength results of the concrete containing treated PET indicated that there is a potential for microwave treatment to be used as a method to induce surface modification.

The Paris Agreement, with its target of net-zero emissions by 2050, has forced the concrete industry to reduce its energy consumption and carbon emissions. Therefore, the development of green concrete with a lower environmental impact is urgently required. In this case study, alum sludge was used as both sand and cement replacement in concrete blocks, and the compressive behaviour of concrete blocks and constructed masonry walls was first investigated. For cement replacement, the strength of blocks decreased with increasing alum sludge ash (ASA) content when the cement replacement ratio was higher than 10% by weight. These results were attributed to the fact that the filler effect and pozzolanic reaction of ASA compensated for the cement dilution effect at a moderate replacement ratio. However, the cement dilution effect dominated the mechanism with further ASA addition. For sand replacement, 10% oven-dried alum sludge addition degraded the mechanical performance of blocks significantly due to high organic content, which might hinder cement hydration. The compression behaviour of masonry walls was also influenced by alum sludge, and the testing results showed that the sludge addition increased ductility of the masonry wall but decreased the strength insignificantly. Therefore, the sludge-derived blocks were suitable for masonry application. Furthermore, a life cycle assessment model was developed based on the designed sludge-derived cement supply chain in South Australia. The obtained results indicate that the annual reduced greenhouse gas emissions were around 1,3339,549 tons, which equaled to the amount of greenhouse gas released from 28,898 passenger vehicles driven for a year.

SCN5A gene loss-of-function mutations are commonly associated with Brugada syndrome, which represents a risk of lethal arrhythmias and sudden cardiac death. The present report describes the generation of two human induced pluripotent stem cell (iPSC) lines reprogrammed from two Brugada syndrome affected patients carrying SCN5A mutations, c.53506 G>A and c.2102 C>T, respectively. Pluripotency markers, karyotype stability, and differentiation capability into derivatives of the three germ layers were assessed and described in the present report. These lines can be used as a reliable cell model for Brugada syndrome investigations and characterization of leading cellular mechanisms.

Hypertrophic cardiomyopathy (HCM) is an inherited heart disease that can cause sudden cardiac death and heart failure. HCM often arises from mutations in sarcomeric genes, among which the MYBPC3 is the most frequently mutated. Here we generated two human induced pluripotent stem cell (iPSC) lines from a HCM patient who has a familial history of HCM and his daughter who carries the pathogenic non-coding mutation. All lines show the typical morphology of pluripotent cells, a high expression of pluripotency markers, normal karyotype, and in vitro capacity to differentiate into all three germ layers. These lines provide a valuable resource for studying the molecular basis of HCM and drug screening for HCM.

Concrete mixing in laboratory conditions has a high level of quality control enabling it to achieve the designed workability and strength by accurately controlling the material quantity, mixing sequence, and mixing time. However, concrete mixing in construction sites or plants can suffer from some unpredictable situations, especially when implementing a newly designed concrete mix with uncommon materials in large-scale projects. Crumb Rubber Concrete (CRC) is a class of concrete that is formed by replacing conventional concrete (CC) fine aggregate by crumb rubber made from scrap tyres. CRC is not a completely new concrete class, as it has been researched in the laboratory level for a while. However, mixing CRC in industrial concrete plants and pouring it on-site, has had very limited implementation in Australia. This paper presents a case study of low-strength truck-delivered CRC poured on large-scale composite slabs. The slabs were reinforced by 0.75 mm-thick BONDEK profiled steel sheets and were tested under 4-point bending load. The variables in this study were the concrete material (CC and CRC), compressive strength (10, 20, and 25 MPa), the use of crack inducers (with and without), and the length of shear span (long and short). The low-strength CRC slabs were tested and compared with CC and CRC slabs having satisfactory strength. The results showed that, 30 % reduction in concrete compressive strength did not affect the load carrying capacity of composite slabs under bending, and slabs with 66 % reduction in concrete strength achieved 75 % of the flexural performance of that in conventional concrete composite slabs. This indicated that the flexural behaviour of composite slabs does not depend only on concrete compressive strength, and that the substitution of low-strength CRC in composite slabs can achieve a satisfactory flexural performance.

ABSTRACT: This paper uses a mathematical method to develop an analytical solution to the local buckling behaviour of long rectangular plates resting on tensionless elastic Winkler foundations and under combined uniform longitudinal uniaxial compressive and uniform in-plane shear loads. Fitted formulas are derived for plates with clamped edges and simplified supported edges. Two examples are given to demonstrate the application of the current method: one is a plate on tensionless spring foundations and the other is the contact between the steel sheet and elastic solid foundation. Finite element (FE) analysis is also conducted to validate the analytical results. Good agreement is obtained between the current method and FE analysis. Keywords: Buckling coefficient, Contact buckling, Winkler foundation, Interaction curve, Finite element analysis

Summary: Non-human primates (NHPs) can serve as a human-like model to study cell therapy using induced pluripotent stem cell-derived cardiomyocytes (iPSC-CMs). However, whether the efficacy of NHP and human iPSC-CMs is mechanistically similar remains unknown. To examine this, RNU rats received intramyocardial injection of 1 × 107 NHP or human iPSC-CMs or the same number of respective fibroblasts or PBS control (n = 9–14/group) at 4 days after 60-min coronary artery occlusion-reperfusion. Cardiac function and left ventricular remodeling were similarly improved in both iPSC-CM-treated groups. To mimic the ischemic environment in the infarcted heart, both cultured NHP and human iPSC-CMs underwent 24-hr hypoxia in vitro. Both cells and media were collected, and similarities in transcriptomic as well as metabolomic profiles were noted between both groups. In conclusion, both NHP and human iPSC-CMs confer similar cardioprotection in a rodent myocardial infarction model through relatively similar mechanisms via promotion of cell survival, angiogenesis, and inhibition of hypertrophy and fibrosis. : In this article, Wu and colleagues demonstrate the therapeutic similarities of non-human primate iPSC-CMs and human iPSC-CMs to treat myocardial infarction by improving cardiac function and attenuating myocardial remodeling in a rodent myocardial infarction model. Mechanisms of iPSC-CM therapy include promotion of cell survival, angiogenesis, and inhibition of hypertrophy and fibrosis. Keywords: iPSC-CM, non-human primate, RNA-seq, metabolomics, myocardial infarction