The performance of a series of 1.5 m-long reinforced concrete beams with CFRP plates bonded to the soffit is presented. Effects of the plate length, the reinforcing steel ratio, and the thickness of the concrete cover on behavior of the beams are discussed with particular emphasis on the brittle failure mode of the concrete ripping. It was found that before the brittle failure, the composite action of the beam could be divided into three distinct zones based on the distribution of the strains along the CFRP plate: (1) The “destressed” zone, (2) the “bond development” zone; and (3) the “fully composite” zone. Concrete ripping may be prevented by limiting the strain at the transition point of the composite zone of the plate. An analytical formulation to predict the failure load corresponding to the concrete ripping failure mode is proposed based on composite theory in combination with a strain limiting criterion. The strain limit can be determined based on simple bond tests with various bond lengths for a g...

Risk management is a key concern in public-private partnership (PPP) projects and the efficient allocation of risk remains problematic. Previous studies on PPP practices have documented the prevalence of inefficiency in risk allocation. Nevertheless, the nature of PPP risk misallocation has not been quantitatively described and verified. This study examines risk allocation in the Chinese water sector as it supports the highest number of PPP projects. Based on the expertise of 32 senior practitioners, statistical analysis is used to contrast where risks ought to lie in order to maximize risk mitigation efficiency with where such risks actually lie. The results confirm that current risk allocation practices are far from ideal, with the implication that current practices play a significant role in project failure. Details within the data provide insight into how practitioners should modify current risk allocation practices to better achieve risk management optimization. The lesson learned from this study can be transferred to projects in other emerging PPP markets.

In the last decade, China has implemented more public–private partnership (PPP) projects in the water sector compared to other sectors. However, efficient management of risks in these projects remains problematic. While there have been many studies that have examined risks associated with PPPs in China, the experience of local governments with risks has received little or no attention in the literature. Moreover, the stages at which the risks are significant and how these risks are interrelated have not been researched. This paper examines risks as experienced from the local government’s perspective and how they manifest across five PPP stages: (1) feasibility, (2) procurement, (3) construction, (4) operation, and (5) transfer. The interrelationship between the risks across the PPP stages is also examined. Data was collected via questionnaire surveys and interviews, and it was analyzed using quantitative and qualitative analysis. The findings reveal critical risk for local governments and how their impacts vary across project stages. Some of the risks influence other risks both within and across the five PPP stages. The findings provide significant insight into the dynamic nature risks in PPP water projects, which has important implications for practitioners when developing risk mitigation strategies.

To ensure structural integrity after modification and/or retrofitting, the behavior of strengthened tubular joints needs to be understood. The finite-element method is a useful tool for studying the problem. However, this numerical technique has to be verified by experimental results before being used extensively. In this paper, the ultimate capacity of doubler plate–reinforced tubular joints is studied. To establish a reference point, a doubler plate–reinforced tubular T-joint was fabricated, instrumented, and tested to failure under axial compression brace loading. The structural behaviors were observed and analyzed. It was found that the ultimate capacity was greatly improved by the inclusion of the doubler plate. The experimental load-displacement curves were compared with the finite-element predictions and good agreement was obtained. The finite-element techniques were then verified and could be used to study the ultimate capacity. A behavioral study was then conducted by applying various types of br...

The aim of this paper is to study the stress concentration factors of doubler plate reinforced tubular T joints subjected to various types of basic loading such as axial tension, axial compression, and in-plane and out-of-plane bending. The finite-element method is adopted in the numerical parametric studies to evaluate the stress distribution. To verify the numerical results, a typical full-scale doubler plate reinforced tubular T joint was fabricated and tested. The strain distributions at the intersection region subjected to various combinations of loading were measured. The results from the experiment compared well with the numerical results. The finite-element modeling techniques were then verified to be accurate and reliable. After the verification, a database was generated from a parametric study by varying some geometrical parameters, such as the wall thickness ratio, diameter ratio, etc. A set of parametric equations with the nondimensional parameters as variables was then established for the eva...