采用溪洛渡大坝实际原材料及配合比,在工程现场进行常态混凝土层间结合面的原位抗剪试验.结果表明:混凝土各层间结合工况的f'在1.44 ～0.97之间,c’在3.00～1.85 MPa之间,不含层面连续浇筑的本体混凝土f'为1.80,c’为3.145 MPa;最大法向应力σ为7.12MPa时,本体混凝土极限抗剪强度τ极限为15.96 MPa,各层间结合工况的τ极限在9.67 ～ 12.11MPa之间；除混凝土本体外,层间铺砂浆的τ极限限最高；层面露粗砂且铺砂浆的层面处理方式效果最佳,上层混凝土采用富浆配合比的层间结合效果也较好；层间结合试件的剪切破坏都发生在层面,剪切面普遍平坦,但本体试件剪切破坏面起伏大,大部分特大石被剪断,擦痕分散不匀.试验成果可为溪洛渡水电站大坝混凝土工程质量控制提供依据.%To provide basis for the concrete quality control for Xiluodu dam, we carried out in-situ shear test on normal concrete layers which are poured from the raw material with mix proportion identical to the actual concrete of Xiluodu dam. Results showed that friction factor f' and cohesion c' of the bond surface between concrete layers were respectively between 1. 44-0. 97 MPa and 3. 00-1. 85 MPa, while f' and c' of concrete itself were 1. 80 MPa and 3. 145 MPa respectively. When the maximum normal stress σmax was 7. 12 MPa, the ultimate shear strength Tmax of concrete itself was 15.96 MPa, and Tmax of the bond surface between concrete layers was between 9.67-12.11 MPa. Except from the concrete itself, concrete layers connected with paved mortar has the highest ultimate shear strength. The treatment of exposing coarse sand on the old concrete surface then paving mortar worked best, and the effect of using rich mortar for the upper concrete was favorable. Shear failure of the specimens with concrete layers occurred on the bond surface, and the shearing plane was generally flat. But the concrete itself had uneven failure surface and most of the largest aggregates were sheared off.
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