Publications

Effect of mechanical anchorage on the bond performance of double overlapped CFRP-to-steel joints

Experimental study on FRP-RC beam reinforced with FRP-UHPC hybrid rebars: Parametric analysis

Emission Characteristics of Gaseous and Particulate Mercury from a Subcritical Power Plant Co-Firing Coal and Sludge

Field tests were carried out in a subcritical coal-fired power plant co-firing coal and sludge to analyze the emission characteristics of gaseous and particulate mercury. EPA30B method was applied to determine the mercury speciation in different positions of the flue gas, including the inlet and outlet of the selective catalytic reduction DeNOX system (SCR) and electrostatic precipitator (ESP); PM10 (with aerodynamic diameter ≤10 μm) was collected using a cyclone and a Dekati low-pressure impactor (DLPI). Before accessing the SCR, Hg in flue gas from both single coal combustion and co-firing mainly existed as Hg0; the higher content of Hg in sludge than coal led to the much higher Hg0 concentration for co-firing. The total Hg concentration at not only the SCR inlet and outlet but also the ESP inlet did not change obviously. However, Hgp concentration at the ESP inlet increased significantly, accompanied by a decrease in Hg0. The transformation of Hg0 to Hgp appeared to be more distinct for co-firing. The higher HCl concentration of co-firing derived from the much higher Cl content of sludge than coal, and together with the higher ash content of sludge containing more minerals capable of adsorbing Hg0, may lead to the greater transformation from Hg0 to Hg2+ and Hgp when co-firing. After the ESP disposal, nearly all Hgp was removed along with PM10, and most Hg0 was also removed. The removal efficiency of mercury after the ESP was 92.12% under coal firing and 92.83% under co-firing conditions, respectively. The slightly higher mercury removal efficiency under co-firing should be attributed to the complete removal of the higher concentration of Hgp.

Nickel-catalyzed cross-coupling of organoaluminum reagents with alkynylhalides for the synthesis of symmetrical and unsymmetrical conjugated 1,3-diynes derivatives

Strength of Rc Beams with an Frp-Strengthened Web Opening

Strengthening of RC beams with rectangular web openings using externally bonded FRP: Numerical simulation

Analysis-oriented stress–strain models for ultra-high-performance concrete confined with fiber-reinforced polymer

The use of fiber-reinforced polymer (FRP) jackets or tubes as confining devices can significantly improve the compressive performance of ultra-high-performance concrete (UHPC). For FRP-confined UHPC, an analysis-oriented stress–strain model is essential for a comprehensive understanding of its compressive behavior and the development of design models. Although several analysis-oriented stress–strain models have been developed for FRP-confined normal-strength concrete (NSC), such models for FRP-confined UHPC are still lacking. In this study, an experiment is conducted to investigate the failure mechanism of UHPC confined with FRP under concentric compression, and the stress–strain behavior of the FRP-confined UHPC is analyzed using the stress–strain models of actively-confined UHPC. Results showed that the stress-path-independency assumption, which has been proven to apply to FRP-confined NSC, was inapplicable to FRP-confined UHPC. By modifying the confining pressure to consider the influence of stress-path dependency, an analysis-oriented model was proposed. The proposed model was verified using a collected test database. The results show that the proposed model accurately predicted the stress–strain behavior of FRP-confined UHPC.

Physicochemical properties and potential health effects of nanoparticles from pulverized coal combustion

Mechanisms of the central mode particle formation during pulverized coal combustion

Determination of fracture toughness of an adhesive in civil engineering and interfacial damage analysis of carbon fiber reinforced polymer–steel structure bonded joints

Carbon fiber reinforced polymer–steel structural bonded joints are often subject to mixed-mode loading i.e. coupling action of normal and shear stress occurs in the joints. In this paper, an experimental approach based on fracture mechanics was adopted to obtain the fracture toughness (G ΙC and G ΙΙC ) of an adhesive currently employed in civil engineering applications, with the corresponding pure cohesive models verified by numerical results. Furthermore, feasibility of the mixed-mode cohesive model for the current adhesive was validated through comparison of numerical and experimental results of carbon fiber reinforced polymer–steel single-lap joints. Finally, based on the validated mixed-mode cohesive model, the interfacial damage of carbon fiber reinforced polymer–steel beam joints was analyzed using the finite element method, accounting for the long-term degradation that can occur in the joint materials i.e. carbon fiber reinforced polymer and adhesive. The work in this paper can provide some useful data such as the fracture properties of the adhesive and shed some light on the design optimization of carbon fiber reinforced polymer–steel structure joints as well as the estimation of its long-term interfacial behavior when in service in civil engineering applications.

Shear strengthening of RC beams with NSM FRP. I: Review of strength models

Near-surface mounted (NSM) fiber-reinforced polymer (FRP) technique is known as a promising alternative to the externally bonded (EB) FRP technique for strengthening reinforced concrete (RC) members, on account of its many advantages such as high bond efficiency with concrete and good durability. Shear strengthening of RC beams by near-surface mounting the FRP bars/strips into the concrete cover on beam sides is one of the most prevalent applications of NSM FRP. Abundant experimental studies have been conducted to investigate the behaviour of NSM FRP shear strengthened beams, and many strength models for predicting the contribution of NSM FRPs to the shear capacity of the beam have been proposed. The present paper presents a comprehensive review of these strength models, in which all the models collected from the existing literature are first classified into three categories based on their used approach and then summarized and discussed. This paper not only aims to bring a deep understanding of the existing strength models for NSM FRP shear strengthened RC beams, but also provides a background and basis for the assessment of these models by using the newly-generated experimental database in the companion paper.

Compressive behaviour of FRP-confined rubber concrete

Coal conversion processes. Part II. Assessment of multienergy product processes utilizing COED char, oil and gas. Interim report No. 5 for period August 1974--Gebruary 1975

filtration and centrifugation was examined and the economics of the separation has been analyzed in detail for the COED, SRC, and Synthoil processes. In the SRC process the ash separation represented a major portion of the overall fixed capital investment ranging from 23 to 50% for the SRC process. (auth)

Study on shape-stabilised paraffin-ceramsite composites with stable strength as phase change material (PCM) for energy storage

Numerical study on interaction between steel stirrups and shear- strengthening NSM FRP strips in RC beams

RC beams shear-strengthened with externally bonded or near-surface mounted (NSM) FRP reinforcement usually fail by the debonding of FRP in a brittle manner. When the FRP reinforcement debonds, the internal steel stirrups may have not reached their yield strength, so the contribution of the latter to the shear resistance of the beam is compromised to some extent. This phenomenon is referred to as the adverse shear interaction between the steel stirrups and the bonded FRP shear reinforcement. This paper examines such shear interaction in RC beams shear strengthened with NSM FRP strips using a simple computational model. Numerical results obtained from this model show that in such beams, most of the steel stirrups reach their yield strength, so the interaction does not have a significant adverse effect on the shear resistance of the beam. This may be seen as yet another advantage of the NSM FRP strengthening method. Disciplines Engineering | Science and Technology Studies Publication Details Chen, G. M., Li, S. W., Zhang, S. S., Chen, J. F. & Teng, J. G. (2013). Numerical study on interaction between steel stirrups and shearstrengthening NSM FRP strips in RC beams. In R. Al-mahaidi, S. T. Smith, Y. Bai & X. Zhao (Eds.), Proceedings of the 4th Asia-Pacific Conference on FRP in Structures (APFIS 2013) (pp. 1-6). Victoria, Australia: Swinburne University of Technology. This conference paper is available at Research Online: http://ro.uow.edu.au/eispapers/4955 NUMERICAL STUDY ON THE INTERACTION BETWEEN STEEL STIRRUPS AND SHEAR-STRENGTHENING NSM FRP STRIPS G.M. Chen , S.W. Li , S.S. Zhang , J.F. Chen 1,3 and J.G. Teng 2 1 School of the Civil and Transportation Engineering, Guangdong University of Technology, Guangzhou, China 2 Department of Civil and Environmental Engineering, The Hong Kong Polytechnic University, China. 3 School of Planning, Architecture and Civil Engineering, Queen’s University Belfast, UK. Email: J.Chen@qub.ac.uk

IEEE Transactions on Biometrics, Behavior, and Identity Science Publication Information

Effect of crystalline admixtures on shrinkage and alkali-silica reaction of biochar-cementitious composites

This study investigated effects of crystalline admixture (CA) on shrinkage and alkali-silica reaction behaviours of cementitious composites. Addition of 1-1.5 wt% superabsorbent polymer (SAP) completely mitigated autogenous shrinkage while slightly increasing the 120-day total shrinkage of the SP-cement composite by 5.7%, resulting in the highest apparent porosity. 1-1.5 wt% CA addition did not affect the autogenous shrinkage while slightly reducing the 120-day total shrinkage by 10.1%. The combination of CA and waste wood biochar (WWB) reduced autogenous shrinkage by 24.23% and 120-day total shrinkage by 23.6%, resulting in the lowest apparent porosity. The formation of hydration products in the WWB pores and on WWB surface densified the cementitious matrix, leading to a reduction in water evaporation. Furthermore, for specimens exposed to 1M NaOH solution at 80 °C, CA addition significantly reduced the 120-day expansion by 50.6%, while the combination of CA and WWB addition reduced the 120-day expansion by 42.9%.

Using digital image correlation to evaluate the bond between carbon fibre-reinforced polymers and timber

The use of optic measurements such as digital image correlation to take strain measurements of fibre-reinforced polymers bonded to a substrate has been on the increase recently. This technique has proven to be useful to fully characterize the bond behaviour between two materials. Although modern digital cameras can take high-definition photos, this task is far from simple due to the tiny displacements that need to be measured. Consequently, digital image correlation measurements lead to relative errors that, at an initial stage of the debonding process, are higher than those calculated close to the debonding of the fibre-reinforced polymer from the substrate. This study aims to evaluate and analyse the use of the digital image correlation technique on the bond between carbon fibre-reinforced polymer laminates and timber when subjected to a pull-out load consistent with fracture Mode II. To allow the quantification of the relative errors obtained from the digital image correlation measurements during the full debonding process, several strain gauges were used to measure the strains in the carbon fibre-reinforced polymer composite. The accuracy of the digital image correlation measurements is analysed by comparing it with those obtained from the strain gauges, which is a very well-established measuring technique. Another contribution of this study is to check the versatility of the digital image correlation measurements on a broader range of situations. To that end, several timber prisms were bonded with seven different bonding techniques with and without the installation of a mechanical anchorage at the carbon fibre-reinforced polymer unpulled end. The results showed that the digital image correlation technique was able to track the slips calculated from the strain gauge measurements until the debonding load, but after that, some difficulties to measure the displacements of the anchored carbon fibre-reinforced polymer-to-timber joints were detected. The digital image correlation technique also over predicted bond stresses when compared with those taken from the strain gauges, which led to bond–slip relationships with higher bond stresses.