Supplementary cementitious materials (SCMs) are widely used to reduce the cement content to achieve economic and environmental objectives. As a result, understanding the shrinkage of blended cement-based concrete is essential. In total, 21 concrete mixes were produced with type general purpose cement and with cement replacements of 30% by fly ash, 40% and 60% by ground granulated blast furnace slag (GGBFS). The concrete compressive strength ranged from 25 MPa to 100 MPa. Experimental results were also compared with the predictions by models. Additional tests on pastes with the same SCM content were conducted to investigate both autogenous and chemical shrinkage in relation to their time-dependent pore structure refinement. For concretes with strength below 50 MPa, no significant difference in autogenous shrinkage could be observed between the different blends up to 28 days. However, the autogenous shrinkage of GGBFS concrete increased significantly after 28 days, being about 50% higher than all other concretes at 100 days. This late increase in autogenous shrinkage between 28 and 100 days can be attributed to pore refinement processes. No clear difference was observed for GGBFS concretes with strength greater than 50 MPa. Autogenous shrinkage of fly ash concretes was overall equivalent to that of reference concretes.

中文翻译：

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粉煤灰与磨细粒化高炉矿渣混凝土的自收缩

辅助胶凝材料 (SCM) 被广泛用于降低水泥含量，以实现经济和环境目标。因此，了解混合水泥基混凝土的收缩至关重要。总共使用通用型水泥生产了 21 种混凝土混合物，其中 30% 的水泥被粉煤灰替代，40% 和 60% 的水泥被磨碎的粒状高炉矿渣 (GGBFS) 替代。混凝土的抗压强度范围为 25 MPa 至 100 MPa。还将实验结果与模型的预测进行了比较。对具有相同 SCM 含量的浆料进行了额外的测试，以研究与其时间相关的孔结构细化相关的自生收缩和化学收缩。对于强度低于 50 MPa 的混凝土，长达 28 天的不同混合物之间未观察到自收缩的显着差异。然而，GGBFS 混凝土的自收缩在 28 天后显着增加，在 100 天时比所有其他混凝土高约 50%。这种在 28 到 100 天之间自收缩的后期增加可归因于孔隙细化过程。对于强度大于 50 MPa 的 GGBFS 混凝土，没有观察到明显的差异。粉煤灰混凝土的自收缩总体上与参考混凝土相当。对于强度大于 50 MPa 的 GGBFS 混凝土，没有观察到明显的差异。粉煤灰混凝土的自收缩总体上与参考混凝土相当。对于强度大于 50 MPa 的 GGBFS 混凝土，没有观察到明显的差异。粉煤灰混凝土的自收缩总体上与参考混凝土相当。