Wen Ling Tian

Study on Combining Performance of Young and Old Concrete with Mechanical Joint Element

The new way of using mechanical joint element (MJE) to cross the interface of new and old concrete to reinforce the combination is put forward. The splitting strength tests of young and old concrete were carried out to investigate the effects on splitting strength of MJE and different materials used to embed the MJE. The working mechanism of the MJE in split test is discussed emphatically. The shear tests of young and old concrete were carried out too. The effects on shear strength of MJE and interface agent are discussed. The mechanism of MJE in shear test is analyzed synchronously.

Research of Building Energy Efficiency Design and Engineering Quality Management System Based on Network

Based on the analysis of the trends of building energy consumption and the situation of standard of building energy efficiency, the thought of system development for building energy efficiency design and engineering quality management based on Network is proposed. Data control processes, modules and functions of system is introduced. This system is an opening system; it has better adaptable to change of standards.

Analysis on Punching Shear Behavior of the Raft Slab Reinforced with Steel Fibers

The thickness of the raft slab is determined by punching shear. The raft slab is commonly thick, which causes concrete volume is large. Mass concrete can bring disadvantage to the foundation. In order to increase the bearing capacity and reduce the thickness, it is suggested that the raft slab to be reinforced by steel fibers. There are five groups of specimens in this paper. S1 is the common reinforced concrete slab. S2 and S3 are concrete slabs reinforced by steel fibers broadcasted layer by layer when casting specimen. S4 and S5 are concrete slabs reinforced by steel fibers mixed homogeneously when making concrete. The punching shear tests of these slabs were done. The test results indicate that the punching shear capacity of the slab reinforced with steel fibers is higher than that of concrete slab, the stiffness and crack resistance of the steel fibers reinforced concrete slab are better than those of the common concrete slab and the punching shear of the slabs with different construction methods of steel fibers is similar. It analyses the punching shear behavior of the slab reinforced with steel fibers and suggests the ultimate bearing formula. The calculative values are coincided with the measured values well.

Study on Bond Properties of Textile Reinforced Concrete

Textile reinforced concrete (TRC) allows the light weight structures and offers a high effectiveness of the reinforcement by using continuous yarns. The study on the bond behavior between textile and concrete matrix is significant for the development of computational methods that analyze the textile reinforced concrete. The paper analyzes the bonding constitutive model of TRC and the bonding mechanism that the stress is transferred from fine concrete to textile, pointing out quadruple linear model can accurately reflect the bond behavior between fiber and concrete, illustrates the main influences on bond between the fine grained matrix and fabrics based on the pull-out test, the result reveals that with initial bond length increasing, the maximum pull force increases, and increasing concrete strength and improving workability of concrete matrix, epoxy resin impregnating and sand covering of textile as well as prestressing textile can increase the bond strength between textile and concrete. Finally the paper proposes that epoxy resin impregnating and 0.15 ~ 0.30mm sand covering of textile can be used as a practical method of improving bond properties in the engineering.

Experimental Study on Seismic Performance of the Reinforced Concrete Grid-Mesh Frame Wall

In order to validate the seismic performance of reinforced concrete grid-mesh frame wall , four grid frame walls in half size is made with different height-width ratios and different grid forms in the paper. Two of them are filling with cast-in-place plaster as filling material. According to the experimental results of these four walls subjected to horizontal reciprocating loads, we know that the grid-mesh frame walls breaking form are in stages and multiple modes, and the main influencing factors are height-width ratio and grid form, whats more, with cast-in-place plaster as fill material, could not only improve the level of the wall bearing capacity and stiffness, but also improve the ductility and seismic energy dissipation capacity.

Experimental Research on Ceramsite Concrete Beams

Six specimens, including 4 ceramsite concrete beams(one of beams mixed into the polypropylene fiber ) and 2 normal concrete beams, were tested to investigate the flexural behavior. The test results show that cracking load of ceramsite concrete beams is slightly smaller than the ordinary concrete beam and cracking load of ceramsite concrete beams has significantly improved after mixing into the polypropylene fibers. The ultimate load of ceramsite concrete beams are no less than ordinary concrete beam,and fibers have not effects on the increase of ultimate load. Load-deflection curves were compared,and the results show that stiffness of ceramsite concrete beam is less than ordinary concrete beam. Ductility of ceramsite concrete beam is poorer than ordinary concrete beam. Fibers improve the stiffness of ceramsite concrete beam. Cover thickness of concrete beam has little effect on the performance of ceramsite concrete beam.

The Shear-Lag Effect on Curved Box Girder Bridge Considering Prestress and Initial Curvature

According to the principle of minimum potential energy and energy differential methods and assuming the shear lag warp displacement function with consideration of prestressed steel, a set of differential equations are deduced with different boundary conditions in considering moment, torsion, shear lag coupling. And the numerical solution of the differential equations is gained by Galerlein method. In addition, explores the influence on shear lag with prestressed force or not, dead loading, live loading and prestressed forces of the prestessed steels the areas of them basing on the model experiment and finite element model. Comparisons of results for typical numerical examples are given to verify the accuracy and applicability of the present method.

Long-Term Bonding Strength between Flue Gas Desulfurization Gypsum and Polymer Cement Mortar

The uncertainty of long-term bonding strength of flue gas desulfurization building gypsum and cement based construction materials is the major issue impeding the application of flue gas desulfurization building gypsum in construction. A polymer cement mortar is suggested to get high bonding quality with flue gas desulfurization building gypsum. Long-term bonding observation has been carried out to verify the bonding performance of suggested polymer cement mortar with flue gas desulfurization gypsum. The results show that the bonding strength is up to 3.0MPa, and the bonding between them is durable.

Demonstration Project Analysis of Energy Saving Renovation for Existing Building

Building energy efficiency is quite important for the sustainable development of our community.Based on the analysis of the building environment,building envelope,energy consumption of existing buildings and the economic condition of the region in Tangshan,the energy - saving renovation measures of building envelope and heat supply system is decided. Then the energy consumption of the energy - saving renovated building is analysed to verify the renovation results. The measures proposed can be one solution of energy-saving renovation in north region.

The Analysing of Coupled Bending Tosion and Shear-Lag of Curved Box Girder Bridge Considering Prestress and Initial Curvature

Based on the theory of thin-walled curved bar and considered the impact of initial curvature and prestress on the vertical flexure, the shear lag warp displacement function is replenished on the basic deformation of the curved box girder flange plate, for which the longitudinal dispersive function is utilized. According to the energy functional differential methods, the coupled bending tosion and shear lag of elasticity governing differential equations of curved prestressed box girder are deduced with different boundary conditions in considering prestress and initial curvature. The numerical solution is gained by Galerlein method. The calculated value of this article coincides well with the value of the experiment and finite-element method. It builds the theory analysing basic of shear lag effect of curved box girder bridge considering prestress and initial curvature.