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北结合某自锚跨斜拉桥工程现浇预应力混凝土自锚跨箱梁的结构特点,采用正交设计试验开展了C50预应力高性能混凝土的制备研究,在胶凝材料用量490kg/m3、Ⅰ级粉煤灰掺量20%、砂率41%、水胶比0.31的设计参数下制备的混凝土工作性能良好,坍落度/扩展度2h基本无损失,初凝时间30h以上,7d抗压强度超过51MPa。混凝土实际浇筑效果良好,结构无明显裂缝,现场检测混凝土7d平均抗压强度达到50.7MPa,28d抗压强度评定合格。
North with a self-anchored cable-stayed bridge project cast-in-place prestressed concrete self-anchored box girder structural characteristics, the orthogonal design test carried out C50 prestressed high performance concrete preparation studies, the amount of cementitious material 490kg / m3, Grade I fly ash content of 20%, 41% sand rate, water-cement ratio of 0.31 under the design parameters of concrete prepared good performance, slump / expansion basically no loss for 2h, the initial setting time of more than 30h, 7d compression Intensity exceeds 51MPa. Concrete pouring effect is good, no obvious cracks in the structure, on-site detection of concrete 7d average compressive strength reached 50.7MPa, 28d compressive strength assessment.