Applied Mechanics and Materials Vols. 166-169

Abstract: Combined with a project example, this paper introduces the method of cutting-off column and jacking was used in a construction of housing rectification. Based on the monitoring and the analysis of strain data of frame beam and column, the result indicated that strain monitoring can reflect the affection to the building during construction, guide the construction effectively and make the process successful.

Abstract: The effectiveness of four different carbon fiber reinforced polymer (CFRP) hybridized methods to retrofit the high strength concrete columns with shear capacity deficiency for improving the shear behavior is described in this paper. These retrofitting methods include the wrapped jacketing, the L-shaped jacketing combined with wrapped jacketing, the clamp plates plus wrapped jacketing and the L-shaped jacketing, clamp plates and wrapped jacketing. Five specimens were tested under low reversed cyclic loading. The influence of retrofitting on the failure mode, ductility, strength, stiffness degradation, and distribution of CFRP strain is analyzed. The results indicate that the retrofitted specimens exhibit high levels of ductility superior to the reference specimen. Among the four retrofitting methods, the effectiveness of method of only the wrapped jacketing is the worst, the method of the clamp plates plus wrapped jacketing has better performance compared to the method of the L-shaped jacketing combined with wrapped jacketing, and the method of the L-shaped jacketing, clamp plates and wrapped jacketing performs best.

Abstract: This paper presents a new vibration isolation module which is set somewhere out of pier footings of footbridges. The isolation vibration effect of the vibration isolation module was analysed by means of experiment and FEM analysis. The attenuation decibels of the vibration strength were measured and researched under various working conditions. Making use of the finite element program, the new vibration isolation module was simulated and calculated. That the calculated results were in good agreement with the measured ones indicated the reliability of the numerical model. The simulation and measured results suggest that vibration reduction effects are satisfactory. The results can provide reference for vibration attenuation and vibration isolation of footbridges.

Abstract: In this paper, the performances of the fiber reinforced plasterboard filled with concrete under eccentric axial load have been tested. There are three kind of test specimens filled with concrete every one, two or three holes separately. Some helpful performances and correlation rules are got, such as the cracking load, damage load, damaging character, relation of load-displacement and curve of load-strain. These could provide reference experimental data for the next theoretical analysis and engineering design.

Abstract: Modal kinetic energy (MKE) method gives a measure of the dynamic contribution of each finite element model physical degree of freedom to each of the target mode shapes, and provides a rough idea where the maximum responses could be measured. It could help to select those sensor positions with possible large amplitudes, and to increase the signal to noise ratio, which is critical in harsh and noisy circumstances. Kammar proposed a new optimal placement method of triaxial accelerometers based up on the effective independence algorithm (EfI3), which places triaxial accelerometers as single units in an optimal fashion. On the basis of EfI3, this paper fully considers the mutual influence of three directions and makes some improvements for the traditional MKE method. A novel optimal placement method of triaxial accelerometers called MKE3 is proposed which is proved rational and effective by analysis the relationship between the EfI algorithm and MKE method.

Abstract: Because the crack repairing technology is varied, the crack repair application has certain complexity, and part of the project due to the repair technology unreasonable type selection. So it is necessary for all kinds of crack repairing technology was studied, on the basis of the best cost-effective choice method, crack repair engineering for reference. This study presents the basalt fiber cement mortar with BICS comprehensive repair of crack, and experimental research was done, according to the test results and the engineering experience, put forward the basic procedures and technology of crack repair method, providing reference for project application.

Abstract: Fourteen concrete beams reinforced with 500MPa longitudinal steel bars were tested under two-point symmetrical concentrated static loading to investigate their deflection characteristics. And the formula for short-time stiffness specified in the code for design of concrete (GB50010-2010)were evaluated using the experimental results and available test data of 74concrete beams reinforced with 500MPa longitudinal steel bars. The results show that the deflection behavior of beams with 500MPa longitudinal steel bars is essentially similar to that of beams reinforced with conventional steel reinforcements. It is also shown that the formula for short-time stiffness under service loads specified in GB50010-2010 is applicable for flexural members reinforced with 500MPa longitudinal steel bars. Comparisons of the test results with the calculated values for the short-time deflection according to GB50010-2010 show that the code method can be used to estimate the short-time deflection for beams reinforced with 500MPa longitudinal steel bars, but that the method is somewhat less accurate for beams with light reinforcement ratio and low-strength concrete.

Abstract: In this paper, shear study was carried out on four reinforced concrete columns in which two columns were reinforced by CFRP (carbon fiber reinforced plastics). The three main factors: shear span ratio, ratio of longitudinal reinforcement, CFRP paste quantity (layer numbers) were analysied since they affect the reinforced effect of CFRP. Through the experiment and simulation, the results indicate that the shear strength of CFRP strengthened concrete columns is obvious, which shows good agreement with experimental and simulation data.

Abstract: Studies have been carried out to investigate the inhibiting effect of organic corrosion inhibitor (OCI) on steel electrode in 1% NaCl solution using electrochemical techniques. The test results show that the commonly used inhibitors such as triethanolamine (TEA), dimethylethanolamine (AMA) and monofluorophosphate (MFP) as well as their complexes are efficient when used in the chloride solution, while an amine-carboxylate inhibitor (C12) prepared in lab bring an excellent inhibitive performance when added in the chloride solution. Based on the date of linear polarization resistance, the calculated lowest corrosion current of the steel electrode for 10d is about 0.32% of the initial current of the electrode in the chloride solution before adding C12 inhibitor.The date of potentiodynamic scanning curves also show that the inhibitor has self-repair ability even when the steel is localized corrosion attack. The Bode-phase diagram results suggest that the protective layer at the surface of steel becomes homogeneous and compact in the presence of chloride.

Abstract: Mechanical Behavior of 3 high-strength concrete simply supported beams reinforced by HRBF500 steel with different stirrup ratio are simulated by software OpenSees .In order to establish the constitutive relationship of high-strength concrete more accurately, some parameters of modified Kent-Park were adjusted partly. Furthermore, the restraining effect of different stirrup ratio to the core concrete is considered by the concrete strength rasied coefficient k. The analysis results matched the test ones well, indicating that the OpenSees program is effective to simulate the mechanical behavior of high-strength concrete members reinforced by high-strength steel.