Strength and Toughness of Waste Fishing Net Fiber-Reinforced Concrete

In this study, we estimate the potential efficiency of waste fishing net (WFN) fibers as concrete reinforcements. Three WFN fiber concentrations (1, 2, and 3% by volume) were mixed with concrete. Compressive strength, toughness, splitting tensile strength, and biaxial flexural tests were conducted. Compressive strength decreased but other properties increased as a function of fiber proportions. According to the mechanical strength observations and the ductility number, WFN fibers yielded benefits in crack arresting that improved the postcracking behavior and transformed concrete from a brittle into a quasi-brittle material. It is inferred that WFN fiber is a recycled and eco-friendly material that can be utilized as potential concrete reinforcement.

Research on a Trackside Concrete Reinforcement Scheme of a Small Radius Curve at a Junction Section of a Modern Tram

In order to ensure the normal use of a junction section of a modern tram, this paper mainly studied a trackside concrete reinforcement scheme. Firstly, the entire non-reinforcement system model with a small radius curve composed of rail, fastener, fastener cover, flexible material, asphalt layer and track slab was established using the ABAQUS finite element software, and the stress distribution and deformation state of the asphalt layers of the non-reinforcement system model under the social vehicle load were analyzed. Then, the whole system model of the concrete reinforcement scheme was founded, and the stress and deformation of the asphalt layers under the same load were investigated. Finally, the calculation results of the concrete reinforcement model were com-pared with those of the non-reinforcement model, and the reinforcement effect was studied. The results show that the concrete reinforcement scheme significantly reduces the stress and deformation of the asphalt layers and improves the stress distribution and deformation state of the asphalt layers.

A Review on the Application and Morphology of Organic Corrosion Inhibitors

Corrosion is a major challenge in construction technology and manufacturing industry. It does not only reduce the aesthetics of a building but also weakens the structure. Structural weakness caused by rust leads to the reduction in the durability of reinforced concrete. Various efforts and research ranging from prevention to maintenance process are being carried out globally to overcome this problem. Due to the increased awareness of the importance of preserving the environment for health and ecological system, studies are increasingly focused on the use of environmentally friendly corrosion inhibitor. This paper discusses several conditioning methods of using organic corrosion inhibitors in concrete reinforcement. It also takes a close look at the effect of every conditioning method towards the reinforced concrete strength and the mechanism to improve it. The migrating and admixed corrosion inhibitors (MCI) conditioning methods is considered as the best solution so far to enhance corrosion resistance performance that contributes to superior reinforced concrete mechanical strength.

Parametric study on mechanical properties of basalt leno textile applied as concrete reinforcement

In this study, the mechanical properties of the basalt leno textile applied as concrete reinforcement were experimentally investigated considering different parameters including the impregnation materials, geometrical characteristics (the number of yarns, yarn structure, and yarn spacing), and loading rate. The tensile strength, elastic modulus, and failure mode were examined. Furthermore, the force mechanism of impregnated leno textile under tensile load was analyzed. The experimental results showed that the textile with a stiff impregnation material exhibited a higher strength and modulus than that with a flexible material. The leno textile with the straight yarn had a better performance than those with the twisted yarns. Besides, the constraint of the weft yarns is obvious to the textile in the warp direction, while the warp yarn makes no contributions to the bearing capacity of textile in the weft direction. The weft yarn spacing had a significant impact on mechanical properties of the textile in the warp direction. Furthermore, the loading rate of approximately 1.2 mm/min was suggested to determine the maximum force of the impregnated basalt leno textile. A tensile strength model was proposed considering the effects of the impregnation material, consistent deformation, torsion damage, and twisted angle.

Characterization of the Static, Creep, and Fatigue Tensile Behavior of Basalt Fiber/Polypropylene Composite Rods for Passive Concrete Reinforcement

Fiber-reinforced polymer (FRP) composites are becoming more frequently adopted as so-called “corrosion-resistant” concrete reinforcement materials due to their excellent mechanical properties and formability. However, their long-term reliability must be thoroughly investigated in order to understand failure mechanisms and to develop service life models. This study is on the mechanical properties of a prototype basalt fiber-reinforced polypropylene (BFPP) rod under quasi-static and sustained loading. Static strength and modulus at elevated temperatures do not decrease significantly, but the variability in strength increases with temperature, as shown by a Weibull analysis. Creep behavior is typical of unidirectional FRP, where the creep rupture strength follows a power law. Fatigue at various stress ratios R reveals the sensitivity of composite strength to the matrix damage, which increases at lower values of R (i.e., higher stress amplitudes). These results are discussed in the context of service life and concrete structure design guidelines.

Development of a Robot-Based Multi-Directional Dynamic Fiber Winding Process for Additive Manufacturing Using Shotcrete 3D Printin

The research described in this paper is dedicated to the use of continuous fibers as reinforcement for additive manufacturing, particularly using Shotcrete. Composites and in particular fiber reinforced polymers (FRP) are increasingly present in concrete reinforcement. Their corrosion resistance, high tensile strength, low weight, and high flexibility offer an interesting alternative to conventional steel reinforcement, especially with respect to their use in Concrete 3D Printing. This paper presents an initial development of a dynamic robot-based manufacturing process for FRP concrete reinforcement as an innovative way to increase shape freedom and efficiency in concrete construction. The focus here is on prefabricated fiber reinforcement, which is concreted in a subsequent additive process to produce load-bearing components. After the presentation of the fabrication concept for the integration of FRP reinforcement and the state of the art, a requirements analysis regarding the mechanical bonding behavior in concrete is carried out. This is followed by a description of the development of a dynamic fiber winding process and its integration into an automated production system for individualized fiber reinforcement. Next, initial tests for the automated application of concrete by means of Shotcrete 3D Printing are carried out. In addition, an outlook describes further technical development steps and provides an outline of advanced manufacturing concepts for additive concrete manufacturing with integrated fiber reinforcement.

REHABILITATION OF THE PAVEMENT OF FOUR ROUNDABOUTS BY MEANS OF THIN CONCRETE REINFORCEMENT ("THIN WHITETOPPING")

This article describes the design and construction of the structural rehabilitation of the bituminous pavement of four roundabouts by means of the arrangement of a 12 cm layer of vibrated concrete with fibres with very close joints (technique known as "thin whitetopping"). The roundabouts, which belong to the N-II National Road as it passes through La Jonquera (Spain), are subject to high levels of heavy vehicle traffic (IMDp > 4,000 heavy vehicles/day). In the project phase, the causes of deterioration of the original road surface were studied, its remaining bearing capacity was characterised and the thickness of concrete to be used was calculated. In the most damaged areas, the bituminous mixture was completely replaced by a lower quality concrete which was adhered to the concrete of the reinforcement by means of metal connectors. In addition, a detailed design of the transitions between the rehabilitated and the existing pavement and the arrangement of the joints was also carried out. Throughout the document, the different tasks carried out for the design and construction of the adopted solution are described in detail and, finally, design and construction recommendations are provided based on the results obtained. Keywords: Concrete, concrete bonding, Concrete with fibres, Reinforcement of pavements with concrete, Fuel resistance, Whitetopping.