【正文】 ty very much. Another area of development of high performance concrete is a high performance lightweight concrete, as opposed to steel, ordinary concrete strength / weight ratio is very low, 濰坊學(xué)院本科畢業(yè)設(shè)計(jì)外文文獻(xiàn)及譯文 3 mixed with highstrength concrete superplasticizer is significantly enhanced the ratio。 Includes % of tolerance。 performance。 engineering。 1d, 3d, 28d pression strength are 35, 52 and 82 MPa respectively。 with a large number of tiny holes lightweight aggregate to replace part of the normal aggregate, will be able to further improve this ratio. As the aggregate quality of different density of 2020 Kg/m3, pressive strength at 70 ~ 80 MPa highperformance lightweight concrete in a number of countries have already mercialized and used in ponent production. In Australia, Canada, Japan, Norway and the United States, highperformance lightweight concrete has been used in fixed and floating drilling platform。s Two union Square Building 2 Buildings then 90 and 120MPa respectively intensity of highperformance concrete pillars. Application examples: a. highperformance concrete application of C80 highstrength and highperformance concrete in Shenyang Fangyuan Building, Onishi Electric Park, and many other highrise building in the application of concrete filled steel tubular columns. b. Shanghai Research in the field of high performance concrete in a large number of promising results obtained, of which representative results are: China39。 (2) extend the pavement service life。s airports cement concrete pavement construction and road pavement engineering is entering a new stage of development to meet the growing demand for aviation and transportation needs. Marine Concrete Structures Durability of hydraulic structures to enhance port study and propose technical and economic rational, easy to promote the use of a new marine engineering highperformance concrete Span bridges, undersea tunnels and offshore oil platforms, is an instance of this application. Such as: a, Shantou, Hong Kong outside the Deepwater Channel Regulation Project。 (3) Reinforcement and templates in any gap, with a good through capacity, does not produce blocking. According to the requirements of these three characteristics, vibrationfree preparation of selfpacting concrete principles and methods section are as follows: Fresh concrete phase is a particle suspended solids, the continuous medium is a cement paste, which is liquid and Concrete Aggregates, pared with solidphase. All the particles in suspension, mobility and particle balance between segregation is necessary. Free vibration of fresh selfpacting concrete in the absence of external force to be real concrete formwork to give full fill all the gaps and achieve the pact, more importantly, to both good fluidity and stability. In order to obtain high mobility, we must first reduce the friction between the particles. Incorporation of superplasticizer to reduce the surface tension of particles of course is necessary, but vibrationfree performance requirements of selfpacting of view, alone doped superplasticizer was also difficult to achieve, needs to mixed with a certain amount of ultrafine material. To obtain good stability, so that materials are not disintegrate, the liquid must have the appropriate rheology, can not produce bleeding and prevent particle segregation. To achieve this request, also be mixed with an appropriate amount of particle size fine filler and in some cases mixed with viscosity modifying agent (tackifier). In order to be able to flow through the reinforcement of concrete and templates in the gap without creating any obstruction, in addition to the design of engineering structures be selected according to the appropriate particle size and morphology of aggregates, the liquid volume is the amount of its rheological properties important parameters. The rheological properties is based on the Bingham rheological model used to evaluate the viseter, and 濰坊學(xué)院本科畢業(yè)設(shè)計(jì)外文文獻(xiàn)及譯文 7 should have a low yield stress and plastic viscosity appropriate. By rheological point of view, vibrationfree matrix of selfpacting concrete is a free flow of ultrafine paste, the paste is made of cement and posed of fine material, the liquid surrounding the solid particles with the thickness of the serosal layer increases with the increase, while the serosal layer thickness of solid particles in the paste has been filled before the gap between the formation, therefore, the thickness of the slurry affects the shapes by solid particles. For the paste, apart from the requirements of high liquidity, the need of sufficient high viscosity, must be a highviscosity Newtonian fluid, in order to prevent segregation. Vibrationfree selfpacting concrete preparation process as shown. Cement ↓ Ultrafin