钢壳沉管自密实混凝土工作性能评价方法的对比试验研究

自密实混凝土目前尚无统一的工作性能评价方法.通过在室内开展500～850 mm扩展度范围的自密实混凝土工作性能指标的对比试验,从填充性、间隙通过性和抗离析性能三个方面对自密实混凝土的性能评价方法进行了讨论.结果表明:采用坍落扩展度USF、扩展时间T500、L型仪测试通过率H2/H1和视觉稳定性指数AVSI的综合评价指标...

Comparative Test Study on Work Performance Evaluation Methods of Steel-Shell Submerged Tunnel Used Self-Compacting Concrete

There is no unified approach for evaluating the workability of self-compacting concrete. In this paper, comparison tests were carried out to self-compacting concrete with slump expansion of 500 mm to 850 mm by testing three workability indexes: filling ability, passing ability and anti-segregation ability. Evaluation method of concrete performance was then discussed. The results show that the comprehensive evaluation indexes of slump-flow (U_SF), slump time (T₅₀₀), L-type instrument passing rate (H₂/H₁) and visual stability index (A_VSI) provide good characterization to the workability of self-compacting concrete. U_SF and A_VSI provide good evaluation to filling ability to self-compacting concrete. L-type instrument or J-ring test provide good evaluation to passing ability of self-compacting concrete. The stability of on-site concrete preliminarily evaluates by visual stability test (VSI) first, and then by segregation rate sieve test (GTM sieve analysis method) when quantitative evaluation is needed. In addition to GTM sieve analysis method, pressure bleeding test should be added when necessary for the anti-segregation evaluation of concrete of vertical members such as side walls.