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An experimental investigation on the chemical, physical, mechanical, and shrinkage of seawater and sea sand-based ultra-high-performance concrete (UHP-SWSSC) with supplementary cementitious materials (SCM) (i.e. slag and silica fume) is reported. Several mixes were designed with varying proportions of SCMs (25%, 37.5%, 50%, and 62.5% of binder), aggregate source, and water-to-binder ratio. Heat evolution, density, workability, compressive strength development, and long-term autogenous and drying shrinkage of UHP-SWSSC were monitored. Seawater accelerates cement hydration as reflected in the heat evolution, and consequently, dictates the early-age strength, and autogenous shrinkage. SCM addition although limits the early-age strength development offers a comparable 90 days strength. The chloride content increases from marine resources and may limit the application to nonstructural components. Nonetheless, a UHP-SWSSC mix with 50% OPC replaced by 37.5% slag and 12.5% silica fume is recommended in this study, which can achieve satisfactory workability, long-term strength, and shrinkage properties. [ABSTRACT FROM AUTHOR]

Pre-stressed unbonded retrofit (PUR) CFRP strengthening of steel structures is becoming a common method of strengthening metallic structures. This paper presents a comprehensive study on the use of the PUR CFRP-strengthening method for strengthening a steel bridge in Melbourne, Australia. Finite element analysis is performed in this study to model the entire bridge and the strengthened element, and the model is validated using actual on-site measurements which showed the stress developments of two girders before and after strengthening when a fully loaded truck passed over the bridge. A parametric study is performed to investigate the stress development of steel girders strengthened with the PUR system under different girder-deck levels of rigidity. The results showed a perfect match between the finite element modelling and actual measurements, and the effectiveness of the PUR system under critical conditions such as different girder-deck stiffness connection levels. [ABSTRACT FROM AUTHOR]

Cast iron pipes buried between the 1860s and 1980s still account for a significant proportion of the Australian water transmission network, and failure rates of cast iron trunk mains have risen in the past decades. In Australian cities, the manufacturing methods and corrosion mitigation techniques used in cast iron pipes are strongly correlated with the pipeline burial year. This paper introduces an approach to summarise the remaining in service cast iron trunk mains into several cohorts, in order to identify the critical pipelines with high potential of longitudinal fracture in pipe barrels. Despite the various manufacturers and casting moulds used in Australian cast iron pipes, two major cohorts, static and spun cast iron pipes, were identified based on manufacturing methods, material properties, microstructural analysis and wall thicknesses. A statistical analysis confirmed that spun cast pipes have higher burst rates and relatively short life spans than statically cast pipes, evidently due to thinner wall size. [ABSTRACT FROM AUTHOR]

In this research, bone marrow mesenchymal stem cells (BMSCs) were isolated from mouse, and induced differentiation into myocardial cellsin vitroafter overexpression of miR-1a. The results showed that the BMSCs could induce differentiation into myocardial cells under the special condition medium, but when the miR-1a was over-expressed in BMSCs, the differentiation efficiency and induction time of myocardial cells from BMSCs could be promoted. This reason was demonstrated that Delta-like 1 (Dll-1) was a transcriptional repressor of myocardium gene expression during myocardium differentiation, miR-1a reduced Dll-1 levels, leading to the accumulation of myocardium gene mRNA and a dramatic increase in myocardium gene protein. [ABSTRACT FROM PUBLISHER]