The ageing coefficient is required in the age-adjusted effective modulus method to assess the effect of creep in concrete structures subjected to varied stress history. In this paper, experiments were carried out to calibrate the ageing coefficient for early age tensile creep of blended slag and low calcium fly ash geopolymer concrete. The development of total strains of geopolymer concrete under sustained tension, including instantaneous strain, creep strain and shrinkage strain was monitored by using the dog-bone shaped specimens. The specimens were loaded at the age of 2, 3, 4, 7, 14, 21 days, respectively. The strains of the unloaded companion specimens were monitored as well. The development of the creep coefficient $\phi (t,{\tau }_0)$ for geopolymer concrete was calculated based on the experimental results. By using the step-by-step numerical analysis, the ageing coefficient for early age tensile creep of geopolymer concrete was assessed. An ageing coefficient of 0.8 is recommended for structural design. The comparison between calculated and measured tensile strains from the restrained concrete ring test shows the validity of the proposed value of the ageing coefficient.

年龄调整后的有效模量法要求使用老化系数，以评估混凝土在不同应力历程下的蠕变效应。本文进行了一些实验，以校准掺混矿渣和低钙粉煤灰地质聚合物混凝土的早期拉伸蠕变的时效系数。用狗骨形试样监测了在持续拉伸下的地质聚合物混凝土总应变的发展，包括瞬时应变，蠕变应变和收缩应变。标本分别在2、3、4、7、14、21天龄加载。还监测了未装载的伴侣样品的应变。蠕变系数的发展$\phi （Ť，{\tau }_0）$根据实验结果计算了地聚合物的混凝土用量。通过逐步的数值分析，评估了地质聚合物混凝土早期拉伸蠕变的时效系数。建议结构设计的老化系数为0.8。通过约束混凝土环试验计算得出的拉伸应变与测得的拉伸应变之间的比较表明，建议的老化系数值是有效的。