早龄期加载对粉煤灰混凝土变形及强度的影响

研究了粉煤灰掺量、加载龄期和加载应力对粉煤灰混凝土早期变形及加载后强度变化的影响。研究结果表明：随着粉煤灰掺量增加，混凝土的变形量逐渐降低，当掺量为30%时，变形量减少了33.6%；随着加载龄期提前或加载应力增大，粉煤灰混凝土的早期变形量增大，其中，加载应力的影响尤其明显，60%加载应力（60%的标准养护条件下7 d轴心抗压强度）比20%加载应力下混凝土最终变形量增加了277.2%；混凝土初始加载时间提前或加载应力增大会导致加载后粉煤灰混凝土强度下降，加载应力比加载龄期对加载后粉煤灰混凝土强度的影响更明显。

Influence of load on deformation and strength of fly ash concrete at early age

The effect of content of fly ash, load age and stress on the deformation and strength was investigated at early age. The results indicated that creep of FA (fly ash) concrete decreased as content of fly ash increased and the maximum reduction was 33.6% when the content was 30%. Advancing load age and magnifying stress could increase the deformation. Effect of magnifying stress on deformation was drastically, as final creep of FA concrete loaded at stress ratio of 60% exceeded that of concrete loaded at stress ratio of 20% by 277.2%. Advancing load age and magnifying stress could decrease the axial compressive strength of FA concrete after being loaded. Effect of loading stress on the strength was more obvious than loading age.