Advanced Materials Research Vols. 163-167

Abstract: Three-dimensional nonlinear finite element analysis on long-short piles composite foundation is finished by using the Drucker-Prager yield criterion and ANSYS procedure. The influences of length and modulus of long and short pile on long-short piles composite foundation loading characteristics are analysed through research on nine long piles and sixteen short piles. The results are given as follows. The composite foundation settlement decreases linearly with the length of long pile increases. The composite foundation settlement has hardly decreased with the length of short pile increases. These conclusions are of referential value for engineering.

Abstract: In order to optimize the zero block analysis method of continuous beam and continuous rigid frame bridge and provide better service for zero block design, a research for size of geometric model, pre-stressing simulation method, loading method and boundary conditions simulation was made. Some useful approaches for zero block calculation were presented through a lot of variable parameter analysis. A method considering the effect of reinforcement ratio was suggested to further judge calculation results of zero block three-dimensional finite element model (FEM). The results showed that the recommended zero block optimal calculation method has high practical value.

Abstract: Slump and compressive strength of the concrete with different steel slag powder content and different finenesses were discussed in this paper. It was indicated that: 1) High performance concrete with higher strength can be made using ground steel slag powder. 2) The greater content of steel slag powder, the more obvious was the effect of reducing slump losing. 3) About 40MPa concrete can be made using the steel slag powder whose specific surface was 510~600m2/kg under the condition that the content of steel slag powder was 50%~60%. 4) When the content of steel slag to be certain, the finenesses of steel slag powder had little effect on the performance of concrete.

Abstract: This paper discusses that the causes and the corresponding control measures of mass concrete crack in the construction stage. And through the analysis of engineering example, it describes the application of the control measures of mass concrete crack in the basement foundation slab of high-rise building in construction process, and analyses the construction effect of its.

Abstract: Steel-concrete composite beams are composed of concrete slabs and steel girders by shear connectos. Due to the shear lag effect, the longitudinal normal stress of cross section is nonuniform distribution,and it is difficult to analyse the effect of that by ordinary beam theory. A differential equation of equilibrium is constituted corresponding to the compatibility of deformation and the equilibrium of forces about steel-concrete composite beams under particular assumed condition. The method of variable-separating is applied to solve the differential equation with the simply supported boundary condition. An example of steel-concrete composite box girder is given to analyse the effect of shear lag on its stress and approve its applicability.

Abstract: This paper presents research on mechanical behavior of frame-supported transfer beams with or without opening in the high-rise buildings using commercial finite element software ANSYS. The result indicated that the hole only impacted the local stress distribution of transfer beam. From the overall view, stress distribution of frame-supported transfer beam with or without opening was almost same. But hole undermined the whole working performance of transfer beam and reduced transfer beam bearing capacity. Influence of the hole as the result of the stress concentration on transfer beam maked the spot became weak part. This weak spot needed to be strengthened in the practical struction members.

Abstract: The performance of one full scale four- edge fixed reinforced concrete slab under the condition of combined effects of loading and fire was investigated. The specimens design, the test plan, the test contents and the test methods were firstly introduced. Through the experiments, the distribution of temperature field along the depth of the slab and the temperature changes of the inner steel were obtained, as well as the deformation of out-plane and in-plane and the rotation on the edges. The changing of reaction forces on the bearings of the slab with the temperature was also observed. The results indicated that, under the condition of fire, the out-plan deformation of the slab was much bigger than that of the normal temperature; non-linear temperature filed was existed along the depth of the slab; remarkable redistribution of the reaction forces were occurred on the fixed bearings. The fail pattern of the slab under the condition of combined effects of loading and fire was different from the static loading under normal temperature. The slab was suffered reverse forces because of the heat effects; hence the plastic hinge lines with the shape of elliptic basin were appeared on the top of the slab.

Abstract: In this paper, twin tower buildings with large bases were studied. The FEM models with connecting and without connecting buildings were established separately. The dynamic characteristics of both models were studied. The influences of connection over the structure vibration mode and natural vibration period were discussed. The dynamic responses of models were also analyzed by time-domain buffeting analysis method. The influences of the connection over the top of the structure’s lateral displacements, and acceleration and the bottom of the structure’s overall shear forces were discussed also. The conclusion of this paper may provide scientific basis to the structure design.

Abstract: Under the heavy traffic, the stress state of asphalt pavement structure has such a complex change that it is difficult for conventional pavement structural response calculation model to deal with. Therefore, "Pavement structure dynamic mechanical response model under complex stress condition" is established in this paper. Kinds of cases are calculated according to the characteristics of heavy vehicle. Then the FWD deflection test and dynamic strain test are carried out. Finally, the rationality of pavement structural response model calculation model is proved by comparing the test results with the theoretical model calculation results.

Abstract: Several series of concrete aggregates with different content of steel slag, blast furnace slag, coal gangue and fly ash were prepared. The reasonable ratio of raw materials and process parameters to prepare the aggregates were determined by measuring the water absorption, crush indicators and apparent density of the aggregates. The mineral composition and morphology of the aggregates were analyzed by XRD, SEM and EDS. The results showed the aggregate with about 30% steel slag, 50% slag, 20% gangue, and calcined at 1300°C for 90 minutes had the best performance. The water absorption of the aggregate is about 1.55% which is lower than that of the natural aggregates (about 2.2% on average). Both the crushing index (about 11.39%) and the apparent density (2672 kg/m3) of the aggregate meet the requirements of national standards.