著者

梶田 秀幸 中田 善久 桝田 佳寛 笹倉 博行

出版者

日本建築学会

雑誌

日本建築学会構造系論文集 (ISSN:13404202)

巻号頁・発行日

vol.84, no.761, pp.905-915, 2019 (Released:2019-07-30)

参考文献数

19

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In this study, with high strength concrete ranging from slump 21 cm up to slump flow 60 cm as the applicable range; in order to shed light on the steady-state flow of fresh concrete in inclined flow test apparatus, we compared and examined the velocity at the tip of the flow determined the vicinity of the gate and the velocity at the tip of the flow of the inclined portion determined from near the end of the test apparatus. Then, based on the relationship between the apparent shear strain rate and the apparent shear stress determined from the velocity at the tip of the flow of near the end of the test apparatus in the inclined portion, we calculated the apparent yield value and the apparent plastic viscosity, and we examined it appropriateness by comparing with the yield value and the plastic viscosity calculated by Terada et al. In addition, we carried out a pumping experiment with an actual pipe length of about 35m, and in addition to confirming the appropriateness of the apparent yield value and the apparent plastic viscosity from the change in the quality of concrete before and after pumping, with regard to evaluation of pumpability of concrete from the relation of pressure loss inside the pipe, we compared and examined with the outcome of the studies conducted by Wami et al. and Terauchi et al. As a result, the following findings were obtained. (1) By measuring the velocity at the tip of the flow of near the end of the test apparatus in the flow portion of the inclined flow test apparatus, we measure the velocity at the tip of the flow where deformation and flow due to the weight of the concrete is close to the steady-state flow, and we could obtain appropriate apparent yield value and apparent plastic viscosity. (2) We proposed the test method of apparent rheological constants determined from the velocity at the tip of the flow of near the end of the test apparatus in the flow part of the inclined flow test apparatus. (3) As a result of investigating the changes in the quality of concrete before and after pumping, values of the apparent yield value and the apparent plastic viscosity obtained from the inclined flow test were appropriate, and the apparent plastic viscosity may evaluate the viscosity of the concrete. (4) As a result of investigating the relationship with pressure loss inside the pipe, it was found that the apparent plastic viscosity obtained from the inclined flow test shows the plastic viscosity of concrete, and it suggested that it may be possible to evaluate the pressure loss inside the pipe from the product of apparent plastic viscosity and actual discharge amount.