Applied Mechanics and Materials Vols. 501-504

Abstract: This paper described the characteristics of the existing methods of strengthening RC shear walls at home and abroad, and discussed the research and operation of strengthening RC shear walls using these methods. It focused on the performance characteristics of the reinforced shear walls structure such as the bearing capacity, the ductility, the deformation capacity and energy dissipation capacity. And the future research trend of the High Performance Ferrocement Laminate reinforcement method is presented.

Abstract: This paper presents an experimental investigation on the variation of FRP hoop strains around specimen perimeter and along specimen height. A total of 24 concrete-filled fiber reinforced polymer (FRP) tubes (CFFTs) with circular cross-sections were tested under monotonic axial compression. The CFFT specimens were instrumented with numerous lateral strain gauges attached to the FRP tubes to examine the development of hoop strains along the specimen height and around specimen perimeter. Specimens were manufactured with height-to-diameter ratios (H/D) of 2 or 5, with all specimens maintaining a nominal diameter of 150 mm. Additional test parameters selected for this study included amount of confinement and concrete compressive strength. This paper focuses on the experimentally recorded hoop strains and their variation around specimen perimeter and along specimen height. The results indicate that hoop rupture strains along the height of CFFTs become more uniform for specimens with higher amounts of confinement. On the other hand, the variation of hoop strains around the perimeter of CFFTs was not observed to be significantly influenced by height-to-diameter ratio (H/D), concrete strength or amount of confinement.

Abstract: So far, there has been many published articles on the continuous compaction control (CCC), but each of them may only concentrate on one or a few aspects. Hence, it is necessary to systematically and thoroughly introduce the continuous compaction control technique and to analyze advantages and disadvantages of the technique and to find some beneficial solutions to improve the technique. By introducing the definition, system composition, advantages and disadvantages and direction of development, the advanced intelligent compaction (IC) developed and originated from CCC is clearly presented. Nothing is perfect; the feasible and factual improvement measures of IC are put forward. From the above, the entire development of CCC is clearly presented.

Abstract: This paper introduces the test and analysis of shear lag effect of a vast scale model of a continuous box girder with variable depth under symmetric lateral varying concentric loads. The strain distribution of the top plates and bottom ones of three cross-sections is tested, while the concentric loads respectively forced on the middle section and the quartile ones. Those sections are: the root-section of the cantilever, mid-section and one quartile section. Test shear lag coefficients of feature points were got through dividing the test strains to those calculated by elementary beam theory. They are compared with those soluted by method of energy variational calculus. The comparing result shows that the shear lag coefficients of the top plate shift from positive to negative accompanying with the load position from ribs to mid point of top plate. At the same time, the overall shear lag coefficient level increases. Meanwhile that of the corresponding bottom plate distribution character finely changes, but its overall shear lag coefficient declines that means that the contribution to bending resisting of bottom weakens. Lateral position of concentric loads has fine influence on shear lag of those sections relatively far from the loads.

Abstract: Under the impact loads, once the key load-bearing member is damaged, it will endanger the entire building structures. Hence, it is very important to study impact-resistant performance of structural members. In order to verify effectiveness of a new composite protective device proposed in the earlier time, a reinforced concrete beam hinged at both ends was choosen as the observed object. During the process of numerical simulation, the four different protective measures including the unprotected, the rigid, the flexible and the composite one were considered in sequence. Numerical results show that the proposed composite measure can achieve the best protective effect, and it may be considered as a new option for impact-resistant protection of structural memebers.

Abstract: Flexural behavior of BFRP composite bamboo beams is tested with taking the size effect and number of BFRP-plate layers into consideration. The results illustrate that the BFRP-plates enhance the stiffness and ductility of bamboo beam, proving that BFRP plates undertake a portion of tension in the tensile region. With layers of BFRP plates increasing, the enhancing effects more significant. However, strengthening effects decline with the aspect ratio of bamboo beam.

Abstract: This work attempts a new strengthening method (one-step forming) between BFRP (basalt fiber reinforcement polymer) rod and bamboo. The interfacial bonding properties of the one-step forming pull-out specimens are achieved. The specimens are composed of bamboo sticks lamination and recombined bamboo respectively containing the plutruded BFRP rods. Through the experiment, bonding failure modes and typical load-slip curves are obtained. Besides, the ultimate bonding stress is compared to bonded-in method of FRP rod which embedded in wood. At last, anchoring calculation recommendations are delivered.

Abstract: Based on a prestressed concrete continuous rigid frame bridge reinforcement project, the finite element model of the bridge was established, which includes two kinds of work condition of before and after bridge reinforcement. The finite element model had analyzed the change of natural frequency, deflection and bending stiffness after the web reinforcement of a prestressed concrete continuous rigid frame bridge, in which we have got analysis results that web reinforcement bridge deflection is less than before reinforcement, and the changing law is obvious as inversely proportional relationship, at the same time, the changing law of natural vibration frequency of web reinforcement bridge and original bridge is not obvious, so only deflection but natural vibration frequency can effect evaluation of web reinforcement of continuous rigid frame bridge.

Abstract: This paper reports the experimental results of 5 groups of 18 adhesive reinforcement bars in concrete under pullout load. Through observing the experiment process, measuring the characteristic loads, and analyzing the failure mechanism, the behavior of adhesive reinforcement under tensile load is studied and described. Based on the tests and previous findings of other researchers, the five failure modes observed for adhesive anchors can be summarized.The formula to calculate the ultimate strength and some design suggestion are also presented.

Abstract: Excessive large gap of joint between caissons easily lead to the rear backfill leaking into harbor basin, to cause a differential settlement of the rear terminals and even affect the structural stability. With the case about caisson wharf of a harbor in southern China, this paper puts forward a rehabilitation technology of caisson joints with mold bag concrete as the major filler. The key technologies are introduced in detail including the mold bag production and installation, the height computation of laminated pouring of concrete and underwater concreting, etc. This technical maintenance is reasonable in economy and practicable in technology, worthy of promotion.