Advanced Materials Research Vols. 1049-1050

Abstract: In practical steel box girder, the fatigue cracks are inevitably existed in steel bridges after they are burdened with the overloading vehicles and larger numbers of automobiles. How to efficiently detect the fatigue cracks, especially the initial fatigue cracks, become one of the most important question to be solved for the steel box girder. HIROX testing system is based on three dimensional micro detection technique, which was successfully used into the domains of aeronautics and astronautics. Three dimensional micro detection scheme of fatigue cracks in steel box girder with HIROX testing system is studied in this paper. Through the data from the testing design, the important characteristic width and length of the fatigue crack can be achieved, which can be used for the grasping of the mechanism of the steel box girder.

Abstract: Controlling the rheological properties of cement asphalt (CA) mortar has been of great importance to its construction properties. In the present paper, the effects of sand, i.e. particle size and fineness module of sand, sand to paste ratio (R_s/p) and paste film thickness (PFT) on the rheological properties of CA mortar were studied with the use of a rheometer. The results show that the properties and content of sand have a strong influence on the rheology of CA mortar. The yield stress and apparent viscosity of CA mortar is decreased with the increasing of particle size and fineness module of sand and PFT, and the decreasing of R_s/p. The key factor of sand to determine the rheology of CA mortar is the PFT.

Abstract: High performance ferrocement laminate (HPFL) reinforcement method is used in this paper to make a finite element analysis on mechanical properties of five reinforced slab-column members. The analysis shows that the bearing capacity of reinforced slab columns and rigidity of midspan slab band have been improved accordingly. Furthermore, with different layout types (field type, groined type and, cross type) of steel mesh in reinforced layer, reinforcement effect and mechanical behavior of reinforced columns can be different. On the premise that punching shear resistance of original columns is strong enough, cross-type reinforcement is the best bending resistance reinforcement pattern of the best reinforcement effect with field-type reinforcement as the second. A reasonable selection of reinforcement pattern shall be made on the basis of the structure’s own mechanical characteristics while a reasonable reinforcement pattern can both ensure the effect of reinforced columns and cut the costs. Conclusions of the paper are supposed to provide some references for reinforcement design in practical engineering.

Abstract: The development of mining activities had destructed and occupied a large amount of land resource, the ecological recovery has become one of the urgent problems of current world especially in China. Mine reclamation can revivify the utilization function of mining land, protect the farming land and renovate the ecologic environment. Zhu Ma-dian has rich mineral resources, part of the mine resources dried up after many years of mining activities, the reclamation of the closed mine pits and abandoned mine land is very urgent. This paper briefly introduces the use city sewage sludge to reclamation of the closed mine pits and abandoned mine land and treat high slope.

Abstract: The tailings dam safety situation is not optimistic in our country, the accident of tailings dam do great harm to people's safety and state’s property. In this paper, based on methods Sweden arc method and Bishop method which were written in the latest tailings dam design specification. Firstly, the paper verifies the security of the tailings under the normal working condition. Secondly, the paper simulates the flood of dam body seepage field and sliding field contours on the assumption of multiple conditions, coming out the safety coefficient. Finally, the author put forward many control Suggestions and measures for the safe operation of the tailings.

Abstract: The agent with a function of controlling the release rate of the anti-icing modifier used in the asphalt mixture was researched in this paper. The purpose is to make the salt components’ release rate controllable and extend the usage life of the anti-icing modifier. Apply the “Rapid Determination of Chloride Ion Content Instrument” to assess the release rate of the different agents. Research and analyze the impact on the anti-icing modifier’s durability brought by the different agents.

Abstract: With the high-speed development of urbanization and the strengthening of new countryside construction, traditional houses of Tujia minority in western Hunan are facing a severe test. Nowadays, it has become a difficult problem that how to make the vanishing traditional houses not only get effective preservation but also can continue to use for residents. This paper takes the architectures of Huochang Tujia Township, Yuanling County in western Hunan as an example, through the analysis of the existing situation of the architectures of market town, puts forward some measures of preservation and renovation.

Abstract: In order to research on the influence law of fine soil strength affected by plasticity index, moisture content,compactness, the unconfined compressive resilient modulus of the soil is as the evaluation index of remolded soil strength. Three fine soils with different plasticity index are selected from field. Test scheme was obtained with the method of orthogonal design. By the static molding method,the soil sample was compacted from the prescriptive moisture content and compactness. The unconfined compressive resilient modulus of the soil sample were tested respectively. The experiments show that sort of influencing factors is plasticity index, moisture content, compactness. With the increase of plasticity index, remolded soil strength increases and increasing extent is significantly large. With the increase of moisture content, remolded soil strength decreases and increasing extent is larger. With the increase of compactness, soil subgrade strength increases, but increasing extent is significantly small.The exponential function is adopted for multiple nonlinear fitting. The relationship between the unconfined compressive resilient modulus and plasticity index, moisture content, compactness is obtained and shows a good correlation.

Abstract: This paper deals with the effect of calcium leaching on the microstructure and rupture strength of cement asphalt (CA) mortar. It is conducted by an accelerated experiment method with species obtained from construction site. Results show that the leaching process mainly contains a total leaching of CaOH2 (CH) and some other cement hydrations. The leaching is proved by the “portlandite dissolution front” on the cross-section of species using a reagent of phenolphthalein. As time goes, the species are continually leached, and then the loss of mass and porosity ratio are obviously increased. Fick’s law can describe the relationship between leaching depth and time very well. The loss of mass and increasing of porosity ratio respond to the shrinking of mechanical properties of CA mortar.

Abstract: To get the maximum coal in front of the working face of the 17# coal seam, we installed a longer beam which is 1.2m in length in the leading end of the original working face supports ZF3000/17/28, and know that working face supports’ setting load and working resistance are lower .We changed the original supports with shield supports ZY3800/15/33 that are adaptable in the geological condition and got the favorable affection.