Shrinkage of Precast, Prestressed Self-Consolidating Concrete
Shrinkage of Precast, Prestressed Self-Consolidating Concrete
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DOI：
10.14359/51663751
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发表时间：
2010-05
影响因子：
1.7
通讯作者：
K. Khayat;Wujian Long
中科院分区：
文献类型：
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作者：
K. Khayat;Wujian Long
正确评估收缩对预应力结构构件的设计至关重要。对预制预应力自密实混凝土（SCC）的自收缩和干燥收缩进行了试验研究。16个SCC，坍落度为680 ± 20 mm（26.7 ± 0.8 in.）进行了评估。这些混合物是用440至500 kg/m³（742至843 lb/yd³）的粘结剂，MS型水泥或HE水泥;和20%的F级粉煤灰; 0.34至0.40的水-胶凝材料比（w/cm）;粘度调节剂含量为0至100 mL/100 kg（0至1.53 fl oz/cwt）粘合剂，砂与总骨料的体积比为0.46至0.54。两种高性能混凝土（HPC），0.34和0.38 w/cm，坍落度为150 mm（5.9 in.）并进行了比较。自密实混凝土在300天的干燥收缩比高性能混凝土高5-30%，但具有相似的自生收缩。将收缩率与AASHTO 2004和2007、CEB-FIP 90、GL 2000和ACI 209 R提出的预测模型进行了比较。CEB-FIP 90和修改后的AASHTO 2004模型被发现提供了足够的预测收缩预制，预应力SCC。
Proper evaluation of shrinkage is critical for design of prestressed structural members. An experimental program was undertaken to evaluate autogenous and drying shrinkage of precast, prestressed self-consolidating concrete (SCC). 16 SCCs with a slump flow of 680 ± 20 mm (26.7 ± 0.8 in.) were evaluated. These mixtures were made with 440 to 500 kg/m³ (742 to 843 lb/yd³) of binder, Type MS cement or HE cement; and 20% Class F fly ash; 0.34 to 0.40 water-cementitious material ratio (w/cm); viscositymodifying admixture content of 0 to 100 mL/100 kg (0 to 1.53 fl oz/cwt) of binder, and 0.46 to 0.54 sand-to-total aggregate volume ratio. Two high-performance concretes (HPCs) with 0.34 and 0.38 w/cm and slump of 150 mm (5.9 in.) were also studied. The SCC developed 5-30% higher drying shrinkage at 300 days than the HPC but with similar autogenous shrinkage. The shrinkage was compared to prediction models proposed by AASHTO 2004 and 2007, CEB-FIP 90, GL 2000, and ACI 209R. The CEB-FIP 90 and a modified AASHTO 2004 model was found to provide an adequate prediction of shrinkage for precast, prestressed SCC.