[Slide] ball hinge support the basic requirements for concrete cement, sand, stone, water, Mixed agent mixed material quality and specifications must comply with the relevant technical specifications, according to a predetermined ratio with construction. Support cushion stone not appear dew angle, hollow, cellular, Ma surface phenomenon and any cracks. [Slide] specify the contents of a ball joint bearing "Highway Bridge Engineering Quality Inspection and Evaluation Standards" civil engineering (JTG F80 / 1-2004) Appendix D concrete compressive strength assessment are as follows: Recently, the highway bridge design, construction specifications have carried out amended to include concrete with strength grade nominal, and this standard and GB "concrete strength inspection and assessment" (GBJ 107-87) consistent. Strength rating C is a side 150mm cube specimen, according to standard methods for making and testing, compressive strength 28d age range of 95% guaranteed rate of the past relationship between the concrete grade M and the C = M-2, which units of Mpa [slide] ball joint bearing industry problem: more steel, GQF-f80-type expansion joints, the use of steel is a strategic national policy of resource use, development should be encouraged and strengthened. But the company did not return on short-term benefits, it is difficult to be widely used. [Slide] ball hinge support the concept behind the long-term economic plan, inadequate product refinement, low value-added steel base of support is far from strong. [Slide] ball bearing hinge largest construction market that is relatively backward, many stakeholders in the development of housing construction, design and use are in-depth, but rights, responsibilities and inadequate protection of private ownership. Finally, the rapid development of steel undertakings is conducive to the stable development of the national economy, we expect steel suppliers, steel companies and steel manufacturers together form industry alliances, and work together to enlarge and strengthen the steel industry, manufacturing strong, national will be powerful. [Slide ball bearing hinge install basic requirements [slide] ball joint bearing pad stone] and quality inspection and assessment stopper According to China "Highway Engineering Quality Inspection and Evaluation Standards" civil engineering (JTC F80 / 1-2004) the provisions of support cushion stone and basic requirements stopper, found the project to identify quality requirements and appearance, with clear inspection and assessment, which is the final project acceptance criteria. Currently steel industry problems [slip] the superiority of steel ball bearing hinge, recycling economy and sustainable development has been recognized by society and gradually expand the scope of the market, 80 expansion joint, but by the national industrial policy support and competent department of the attention is not enough, the current strength of the national development is very weak, poor innovation, the main problem restricting the development of the steel structure has the technical aspects: 1, slightly higher than the 10 percent the cost of a single structure of reinforced concrete structures, reduced foundation, sand car cost stone cement, transportation, time does not really stand out costs. 2, steel talent less, GQF-C80-type expansion joints, developers and designers willing to adopt proven convenient brick structure, reinforced concrete architecture. 3, steel corrosion, fire protection technology and products do not know enough, blind mandatory cost increases, the impact of application. 4, related to steel standards, regulations, norms imperfect, Revision Preparation lag, a serious shortage of research and development funds, market-oriented concepts to prepare standards, inevitably mixed.