Advanced Materials Research Vols. 712-715

Abstract: with the rapid development of high-rise building structure, composite structure given priority to concrete filled steel tube is widely used in high-rise structure construction, the mechanical characteristics of concrete filled steel tubular has made a lot of research at the moment, and in optimization of economic indicators still needs further in-depth. In this article, economic indicators mathematical model of rectangular concrete filled steel tubular axial compression member is built by the MATLAB language, in order to achieve the aim of economic indicators optimization and provide an important reference for the engineering design and theoretical basis, a reasonable set of cross section form with the highest ratio of axial compression components is found through the model analysis of engineering examples.

Abstract: This paper presents the probabilistic assessment to analyze the resistance of the unsymmetrical effects (accidental torsional effects, soil-structure interaction, and seismic action) to symmetrical high rise buildings. The Eurocode requires that the seismic resistance of structures must be checked to the accidental torsion effects. In order to cover uncertainties in the location of masses and in the spatial variation of the seismic motion, the calculated centre of mass at each floor shall be considered displaced from its nominal location in each direction by an accidental eccentricity due to the requirements of ENV 1998. Recent advances and the general accessibility of information technologies and computing techniques give rise to assumptions concerning the wider use of the probabilistic assessment of the reliability of structures through the use of simulation methods. The possibilities of the utilization the RSM method to analyze the extensive and robust tasks in FEM is presented in the case of the buildings with central core and columns system. The deterministic and probability analysis of the seismic resistance of the structure was calculated in the ANSYS program.

Abstract: The inadequacy of many existing roads due to rapid growth in traffic volume provides a motivation for exploring alternatives to existing methods of constructing and rehabilitating roads. The use of geosynthetics to stabilize and reinforce paved and unpaved roadways offers one such alternative. Many studies were conducted to evaluate the improvements associated with geogrid reinforcement of pavements. It is widely believed that geogrid reinforcement of roadways can extend the pavements service life and/or reduce the pavements structural thickness. This paper examines a method to compare traditional pavement structure designs, absent of geosynthetics, to pavement structure designs incorporating geosynthetics. At first, a specific unpaved road structure design is presented with recommended corresponding traditional road structure components. The road structure is then re-examined incorporating newly developed, reengineered geogrid. Finally, related costs with this particular design are outlined, analyzed and compared. In this case, cost savings achieved by using geogrid are substantial.

Abstract: This paper analyzed the application of the solar house and solar radiant floor heating in building energy conservation. It also introduced the situation of the solar energy utilization in foreign countries.

Abstract: Foundation excavations support and dewatering method have been full-grown after years of development. However, during the excavation of polluted soil in special sites, dewatering scheme should not simply based on the experience and form of excavation but should be combined with the characteristics of contaminated sites so as to choose a reasonable dewatering method which meets the construction requirement of soil excavation on one hand and prevents the spread of contamination on the other hand. This paper design and analysis the dewatering of soil excavation in contaminated sites combined with specific project example.

Abstract: The concrete-cored DCM pile is an kind of composite pile by inserting the inner concrete pile into the DCM column socket. In two test sites, plate load test is used to measure bearing capacity of concrete-cored DCM pile composite ground. Vertical stress of surrounding soil and DCM column socket are measured by pressure cells. The axial force of precast core pile can be obtained by steel stressmeters which welded on the reinforcing steel along depth. The field tests results show that, the bearing capacity of concrete-cored DCM pile composite ground is much larger than that of original soil. The development degree of concrete-cored DCM pile bearing capacity in composite foundation increases steadily during the loading process. Both concrete-cored DCM piles and surrounding soils play an important effect on the bearing capacity of composite foundation.

Abstract: Concrete was used for construction in many ancient structures. Concrete technology was known by the Ancient Romans and was widely used within the Roman Empire. After the Empire passed, use of concrete became scarce until the technology was re-pioneered in the mid-18th century. The widespread use of concrete in many Roman structures has ensured that many survive to the present day. The development of reinforced concrete marked the dawn of a new age. For it was the first heterogeneous building material, using steel, cement, sand, gravel, and water. This composition possessed much better properties than each of its individual components.

Abstract: In this paper, a method of aggregate surface modification using cement paste with RLP (Redispersable Latex Powder) was proposed aiming to improve properties of recycled aggregates and the resulting concrete. In this study, the cement pastes with different dosages of RLP on RA surface modification were used and the effects on the mechanical properties of the resulting concretes were studied. The experiments were carried in accordance with specifications and test methods in Building pebble and gravel (GB/T 14685-2001) and Ordinary concrete mechanics performance test method standard (GB/T 50081-2002). The test results showed that the properties of recycled aggregates were not as good as those of natural aggregates, thus resulting in poorer mechanical properties of the recycled aggregate concrete. By means of aggregate surface modification, the values of water absorption of the recycled aggregate were reduced and consequently the mechanical properties (i.e. compressive strength and elastic modulus) of the resulting recycled concrete were increased. This research provides some useful practical insights to improving mechanical properties of recycled aggregate concrete.

Abstract: The present status of reinforced concrete structure confined by FRP is introduced, and the recent technical researches of reinforced concrete beams and columns confined by BFRP are summarized. Based on those researches, the mechanical properties and calculation models are analyzed. At the same time, the seismic performance of reinforced concrete beams and columns confined by BFRP is also explored.

Abstract: This article deals with determination of bulk density of bitumen waterproofing sheets using different methods, namely calculation and experimental measurement. Volume density actually well reflects bitumen sheet composition. Composition of bitumen sheet is the factor that influences the hydro insulation function.