Efficiency of CFRP NSM strips and EBR laminates for flexural strengthening of RC beams

The efficiency of Fiber Reinforced Polymer (FRP) materials for strengthening existing Reinforced Concrete (RC) structures according to the Near Surface Mounted (NSM) technique can be greater than the External Bonded Reinforcement (EBR) technique since the tensile strength of the FRP materials is in general better exploited. Firstly, this paper deals with analyzing the effect of the loading pattern on RC beams strengthened with both types of strengthening technique; in particular, two loading patterns have been used for the experimental tests on simple supported beams: 1) a four points bending scheme, and 2) a scheme with distributed loads, in order to check the sensitivity of failure modes and ultimate loads to different distributions of bending moment and shear along the beam. Then, a comparison between the results of flexural tests on RC beams strengthened with both NSM and EBR techniques is dealt with

Assessment of nonlinear bond laws for near-surface-mounted systems in concrete elements

This paper presents a numerical plane Finite Element (FE) Model for use in simulating the behaviour of different types of Near Surface Mounted (NSM) Fibre Reinforced Plastic (FRP) strengthening systems for concrete elements. Based on a nonlinear bond law for simulating the behaviour of the FRP reinforcement-adhesive-concrete interface, the model employs an interface element between the NSM FRP reinforcement and the concrete. The results of two different experimental programs, both dealing with 'bond tests' but with distinct set-ups, are briefly summarised and analysed. The main objective of this research is to assess the values of the parameters that define the nonlinear bond laws for each type of FRP reinforcement tested. This assessment was accomplished by inverse analysis, fitting numerically the pullout load–displacement curves that were experimentally recorded. The effect of bond length on different types of NSM FRP reinforcement is assessed. Finally, the bond behaviour in the transverse plane is examined too.Fundação para a Ciência e a Tecnologia (FCT

Assessment of non linear bond laws for NSM systems in concrete elements

In this paper the numerical FEM model developed to simulate the behaviour of the NSM strengthening system for concrete elements is presented. The plane model introduces the non linear bond law of the system by an interface element between the composite reinforcement and the concrete considered linear. The results of two experimental programs are analysed and used to calibrate the parameters of the bond shear-slip relationship by means the numerical model. The procedure is based on the inverse analysis of the experimental data in order to have the better fitting of the global pull-out load-displacement curves.(undefined

Bond of NSM FRP strengthened concrete: round robin test initiative

Despite the extensive research that has been conducted on the debonding behaviour of FRP strengthening systems, no standard methodology has been yet established on its experimental characterization. In this context, to assess the performance and reliability of small scale testing on NSM (near surface mounted) FRP strengthening systems, an experimental program was carried out on a series of nine NSM FRP strengthening systems, in the framework of an international Round Robin Testing (RRT). Eleven laboratories and seven manufacturers and suppliers participated in this extensive international exercise, which regarded both NSM and EBR FRP strengthening systems. Test results obtained for the NSM systems by the participating laboratories are discussed and compared in this paper to investigate the feasibility of the adopted single/double pulling shear test method, to investigate the mechanism of bond between NSM FRP reinforcement and concrete, and to investigate the level of variability obtained between the participating laboratories testing the same material batches. It is concluded that the tested variants in the adopted single/double shear pulling test have a significant influence, stressing the importance of the level of detail of standardized test protocols for bond verification. On overall, given the variants included in this study, the obtained variation in bond stress-slip behaviour between the laboratories remained fairly limited.The authors wish to acknowledge the financial assistance of the European Union for the Marie Curie Research Training Network En-Core, and the support of TG 9.3 of the International Federation for Structural Concrete (fib). Hughes Brothers and Fortius, Magmatech, Schock, S&P, Sika, ATP, and Sto Scandinavia AB are acknowledged for their participation in the RRT and for supplying the test materials

Burden-driven feedback control of gene expression

Cells use feedback regulation to ensure robust growth despite fluctuating demands for resources and differing environmental conditions. However, the expression of foreign proteins from engineered constructs is an unnatural burden that cells are not adapted for. Here we combined RNA-seq with an in vivo assay to identify the major transcriptional changes that occur in Escherichia coli when inducible synthetic constructs are expressed. We observed that native promoters related to the heat-shock response activated expression rapidly in response to synthetic expression, regardless of the construct. Using these promoters, we built a dCas9-based feedback-regulation system that automatically adjusts the expression of a synthetic construct in response to burden. Cells equipped with this general-use controller maintained their capacity for native gene expression to ensure robust growth and thus outperformed unregulated cells in terms of protein yield in batch production. This engineered feedback is to our knowledge the first example of a universal, burden-based biomolecular control system and is modular, tunable and portable

Pathways to cellular supremacy in biocomputing

Synthetic biology uses living cells as the substrate for performing human-defined computations. Many current implementations of cellular computing are based on the “genetic circuit” metaphor, an approximation of the operation of silicon-based computers. Although this conceptual mapping has been relatively successful, we argue that it fundamentally limits the types of computation that may be engineered inside the cell, and fails to exploit the rich and diverse functionality available in natural living systems. We propose the notion of “cellular supremacy” to focus attention on domains in which biocomputing might offer superior performance over traditional computers. We consider potential pathways toward cellular supremacy, and suggest application areas in which it may be found.A.G.-M. was supported by the SynBio3D project of the UK Engineering and Physical Sciences Research Council (EP/R019002/1) and the European CSA on biological standardization BIOROBOOST (EU grant number 820699). T.E.G. was supported by a Royal Society University Research Fellowship (grant UF160357) and BrisSynBio, a BBSRC/ EPSRC Synthetic Biology Research Centre (grant BB/L01386X/1). P.Z. was supported by the EPSRC Portabolomics project (grant EP/N031962/1). P.C. was supported by SynBioChem, a BBSRC/EPSRC Centre for Synthetic Biology of Fine and Specialty Chemicals (grant BB/M017702/1) and the ShikiFactory100 project of the European Union’s Horizon 2020 research and innovation programme under grant agreement 814408

Common and rare variant association analyses in amyotrophic lateral sclerosis identify 15 risk loci with distinct genetic architectures and neuron-specific biology

A cross-ancestry genome-wide association meta-analysis of amyotrophic lateral sclerosis (ALS) including 29,612 patients with ALS and 122,656 controls identifies 15 risk loci with distinct genetic architectures and neuron-specific biology. Amyotrophic lateral sclerosis (ALS) is a fatal neurodegenerative disease with a lifetime risk of one in 350 people and an unmet need for disease-modifying therapies. We conducted a cross-ancestry genome-wide association study (GWAS) including 29,612 patients with ALS and 122,656 controls, which identified 15 risk loci. When combined with 8,953 individuals with whole-genome sequencing (6,538 patients, 2,415 controls) and a large cortex-derived expression quantitative trait locus (eQTL) dataset (MetaBrain), analyses revealed locus-specific genetic architectures in which we prioritized genes either through rare variants, short tandem repeats or regulatory effects. ALS-associated risk loci were shared with multiple traits within the neurodegenerative spectrum but with distinct enrichment patterns across brain regions and cell types. Of the environmental and lifestyle risk factors obtained from the literature, Mendelian randomization analyses indicated a causal role for high cholesterol levels. The combination of all ALS-associated signals reveals a role for perturbations in vesicle-mediated transport and autophagy and provides evidence for cell-autonomous disease initiation in glutamatergic neurons