Studies Of Self-Compacting High-Strength Concrete And Earthquake Resistance Behavior Of Self-Compacting High-Strength Concrete Frame

Some respects of self-compacting high-strength concrete (SCHSC) made of Fujian province's local material have been studied in this thesis as follows:1. Studies on microstructure of the SCHSC. Three different mixed SCHSC and one normal high-strength concrete(NHSC) were observed by the Scanning Electron Microscope at different sites and different ages of 1 day, 3 days, 7 days, 28 days and 60 days. From the test, the effects due to no vibrating and admixture on the microstructure of SCHSC were studied. The study offers the test evidence to the study of the mechanical properties and the durability of SCHSC. Analyzing the Scanning Electron Microscope image we can obtain results as follows. First, because mixing content of in SCHSC is very high, the degree of hydration is lower than NHSC at early ages. Second, the characteristics microstructure of SCHSC is better than that of NHSC at late ages. Third, the distinction of the microstructure between aggregate interfaces and cement-stone of SCHSC is less than that of NHSC at the same age. The pore of SCHSC is smaller and more homogeneous than that of NHSC. Fourth, the contribution to concrete microstructure of the expanding agent is very little at early ages; however it is obvious at late ages to a certain extent. Fifth, for the contribution of the mixing content of fly ash is that the contribution to the degree of early age concrete hydration is obvious to some extent, and that the contribution to the shape of hydrate of concrete is obvious. Studies on the earthquake resistance behavior of SCHSC frame. In the test, two frames with the same size which is one-half of the reality frame's size and the same reinforcement were designed and made firstly. One frame is made of SCHSC named SF; the other is made of NHSC named NF. Secondly, the MTS loading system was used to put the two frames under low-cyclic loading. Testing the effect of self-compacting concrete's self-compacting construction characteristic and material properties to self-compacting concrete frame's earthquake resistance behavior. And the safety of using self-compacting concrete in earthquake zone was guaranteed. From the test some conclusion could be drawn as follows. Firstly, under the push loading, yield load and exteme load and failure load of SF is higher than that of NF, but the relative2. displacements of two frames is approximately equal. Secondly, the cause of two frames' failure is flexural deformations. Thirdly, the curve of the relations between frame load and frame displacement and the relations between frame load and frame displacement envelopes of SF is similar to that of NF. Finally, the coefficient of ductility of SF is higher than NF's, and the capacity of consuming energy of SF is similar to NF's.3. The field application of SCHSC. Self-compacting concrete of C55 grade was successfully applied to consolidate column of XiaMen south-lake bright pearl engineering, which could provide experience for the applying self-compacting concrete in engineering.