Experimental investigation of seismic performance of a novel isostatic frame-cladding system

A new connection measure between the precast concrete (PC) cladding panel and PC frame structure is proposed to realize a new kind of isostatic frame-cladding system. Three full-scale PC wall-frame substructures were tested under the quasi-static load. These substructures included a bare wall-frame specimen, a specimen with a cladding panel that has no opening, and a specimen with a cladding panel that has an opening in it. The damage evolution, failure mode, load-bearing capacity, deformation capacity, and energy dissipation capacity of three specimens were compared. The results indicated that the motions of the cladding panels and the main structures were uncoupled through the relative clearance of the bottom connections, and three specimens exhibited approximately identical failure modes and seismic performance. Thus, the reliability of this new isostatic system was validated.

Large Torsion Deformation: Centrosymmetric Reentrant Honeycomb

There exist some problems in the crash box and anti-collision beam sandwich structure, such as monotone deformation pattern and uneconomical energy absorption performance. In order to raise the deformation capacity and energy absorption performance of sandwich structure, centrosymmetric reentrant honeycomb (CRH) and hexagonal centrosymmetric reentrant honeycomb (HCRH) are proposed based on auxetic reentrant honeycomb (ARH) in this work. Based on HCRH, four kinds of transverse combination structures and two kinds of longitudinal combination structures are obtained. The results of specific energy absorption show that the energy absorption capacity of the angular contact homodromous combination structure (ACOC) is about 3 times that of the other three transverse combination structures. Compared with longitudinal heterodromous combination structure (LHEC), the energy absorption capacity of longitudinal homodromous combination structure (LHOC) is improved by 72.7%.

Experimental Study on Shear Behavior of Reactive Powder Concrete Beam

In order to study the shear behavior of high-strength reinforced Reactive Powder Concrete (RPC) beams, eight test beams were designed and fabricated for the shear test under symmetrical concentrated load. By observing the development and failure mode of diagonal cracks, the influence of shear span ratio, stirrup ratio, and longitudinal reinforcement ratio on the cracking load, shear capacity, and deflection of the test beam is analyzed. The results show that: in a specific range, the shear capacity increases with the increase of stirrup ratio and longitudinal reinforcement ratio and decreases with the increase of shear span ratio. The shear span ratio has the most significant influence on the component’s failure mode and deformation capacity. The increase of the stirrup ratio can improve the deformation capacity of the component in a specific range. It is conservative to use the code to design concrete structures to calculate the shear capacity of high-strength reinforced reactive powder concrete beams. It is suggested that the shear calculation formula suitable for high-strength reinforced reactive powder concrete should be adopted to make the theoretical calculation results closer to the measured values.

Study on Interaction of RC Pile-Soil with High Reinforcement Ratio of Integral Abutment Bridges under Quasi-Static Test

In order to improve the ability of the reinforcement concrete (RC) pile foundation of integral abutment to absorb the horizontal reciprocating deformation under the action of temperature or earthquake, a pseudo-static low cycle test on interaction of pile-soil with high reinforcement ratio was carried out. The failure location, hysteresis curve, skeleton curve and horizontal deformation of three piles with different reinforcement ratios were compared. The test results show that, with the increase of the reinforcement ratio, the crack of the RC pile develops along the pile body to the depth, and the pile body failure area and the position where the maximum bending moment moves down, the crack resistance of the pile body is improved, and the effective interaction pile length increases; The test results also show that the hysteresis curve of the model pile becomes fuller with the increase of the reinforcement ratio, compared with the RCP-1 specimen with the lowest reinforcement ratio, the equivalent viscous damping ratio of the RCP-3 specimen is increased by 31.6%, and the energy dissipation capacity is improved. In addition, with the increase of the reinforcement ratio, the bearing capacity and deformation capacity of model piles are greatly improved. Compared with RCP-1 specimen, the ultimate bearing capacity of RCP-3 specimen increased by 150%, and the corresponding ultimate displacement increased by 153%. Increasing reinforcement ratio can significantly improve the mechanical properties and deformation capacity of RC pile.

Studying changes of limit deformations and mechanical properties of steels of different structure under single and multiple explosive loading

The ultimate deformation capacity of stainless high-alloyed austenitic nitrogen-containing steel and low-alloyed chromium-nickel-molybdenum steel up to the moment of failure under single and multiple blast loading in the air has been investigated. The paper presents data on the change in the mechanical properties and structure of these steels as a result of explosive loading to the limit and to the specified level of deformation.

Destruição da arte tumular por um preço vil / Destruction of tomb art for a vile price

A arte tumular ou funerária representa o respeito dado a um indivíduo dentro do contexto histórico; acompanhada de grande carga emotiva, deve ser preservada para que este legado afetivo seja reverenciado. O bronze é uma liga metálica composta basicamente de cobre e estanho, contendo ainda outros elementos químicos, fusão que aumenta a resistência do cobre sem alterar sua capacidade de deformação, permitindo a realização de obras de arte. Infelizmente, o cobre presente em artefatos de bronze, desperta a ganância de vândalos, que por alguns trocados destroem a memória de pessoas ilustres e queridas, um quadro revoltante pelo descaso dos responsáveis pela preservação do patrimônio cultural abrigado nos cemitérios. Tanto as placas de bronze, vasos e portas dos jazigos levadas de vários cemitérios estão sendo substituídas por desgraciosas peças de granito, sem valor comercial, porém padronizadas, acabando com as referências que individualizam cada jazigo, denegrindo a memória dos que ali repousam. ABSTRACT Tomb or funerary art stands for the respect given to an individual within the historical context; coupled with a great emotional burden, it must be preserved so that this affective legacy is revered. Bronze is a metallic alloy basically composed of copper and tin, also containing some other chemical elements, and producing a fusion that increases the resistance of copper without altering its deformation capacity which allows the creation of art work. Unfortunately, the copper present in bronze artifacts awakens the greed of vandals who, for a few pennies, destroy the memory of distinguished and beloved people. This is a revolting consequence caused by the negligence of those responsible for preserving the cultural heritage housed in cemeteries. Either the bronze plates or vases and tomb doors taken from various cemeteries are being replaced by clumsy pieces of granite, with no commercial value, but standardized, putting an end to the references that individualize each tomb and disparaging the memory of those who rest there.

Tensile Behavior of High-Strength Stainless Steel Wire Rope (HSSSWR)-Reinforced ECC

Engineered cementitious composites (ECC) show the distinguished characteristics of high post-cracking resistance and ductility. High-strength stainless steel wire rope (HSSSWR) has been successfully used for restoring or strengthening of existing structures. By combining the advantages of these two materials, a new composite system formed by embedding HSSSWR into ECC was proposed and expected to be a promising engineering material for repair or strengthening of structures. To investigate the tensile failure mechanism and mechanical properties of HSSSWR-reinforced ECC, an experimental study on 27 HSSSWR-reinforced ECC plates was conducted considering the effects of the reinforcement ratio of longitudinal HSSSWRs, formula of ECC and width of the plate. Test results revealed that HSSSWR-reinforced ECC exhibit superior post-cracking resistance, deformation capacity and crack-width control capacity. Increasing the reinforcement ratio of longitudinal HSSSWRs can effectively enhance the tensile strength, crack-width control capacity, deformation capacity and tensile toughness of HSSSWR-reinforced ECC. Adding thickener in ECC can significantly improve the crack-width control capacity and deformation capacity of HSSSWR-reinforced ECC due to enhancing uniform distribution of polyvinyl alcohol fibers, but would slightly reduce the cracking stress and maximum tensile stress by bringing small bubbles in the matrix. The tensile properties of HSSSWR-reinforced ECC plates are almost not affected by varying the plate width. Besides, a tensile constitutive model was developed for charactering the stress–strain relationship of HSSSWR-reinforced ECC in tension. Based on mechanical theories and failure characteristics of HSSSWR-reinforced ECC, the model parameters were determined, and calculation equations of cracking stress and tensile strength were proposed. The accuracy of the developed model and calculation equations was verified by test results.