矿物掺合料对再生混凝土早龄期拉伸徐变的影响
Influence of mineral admixture on tensile creep of recycled concrete at early ages

通过对1d龄期的再生混凝土拉伸徐变试件进行单轴拉伸，研究再生粗骨料、单掺粉煤灰和复掺粉煤灰加矿渣对再生混凝土早龄期各类拉伸徐变性能的影响. 结果表明：再生混凝土拉伸徐变性能与普通混凝土类似，呈现早期发展快、后期发展慢的规律；掺入70%再生粗骨料导致再生混凝土各类拉伸徐变增加，拉伸总徐变增幅为8.0%；单掺粉煤灰和复掺粉煤灰加矿渣均导致再生混凝土各类拉伸徐变增加，30%~60%粉煤灰掺量的再生混凝土拉伸总徐变增幅为8.5%~32.5%，30%~60%粉煤灰加矿渣复掺量的再生混凝土拉伸总徐变增幅为2.6%~21.7%；相较于单掺粉煤灰，复掺粉煤灰加矿渣的再生混凝土的拉伸徐变增幅较低.
Uniaxial tension of recycled concrete tensile creep specimens at the age of 1 d was conducted to investigate the influence of recycled coarse aggregate，addition of fly ash and combined addition of fly ash and slag on various types of tensile creep performance of recycled concrete at early age. Test results showed that the tensile creep performance of recycled concrete was similar to that of normal concrete with fast development at the early ages while slow development in the later period. Replacing 70% of natural aggregates with recycled ones increased all types of tensile creep for recycled concrete，the increase of tensile total creep was 8.0%. The addition of fly ash and combined addition of fly ash and slag both led to the rise of all types of tensile creep for recycled concrete，30% to 60% addition of fly ash increased the tensile total creep of recycled concrete by 8.5% to 32.5%，30% to 60% combined addition of fly ash and slag increased the tensile total creep of recycled concrete by 2.6% to 21.7%. Compared with the addition of fly ash，combined addition of fly ash and slag show relatively lower tensile creep for recycled concrete