中文摘要：

为了考察钢筋限制条件下外加剂和掺合料对混凝土早期收缩性能的影响，测量了掺加多种掺合料的钢筋混凝土早期收缩应变和应力的发展情况，应用钢环实验考察了混凝土的早期收缩开裂情况．结果表明，磨细矿渣和硅灰会显著增加混凝土的早期收缩；石灰石粉和粉煤灰能明显抑制混凝土的早期收缩，石灰石粉的效果最好；膨胀剂降低混凝土收缩的早期作用明显；钢环实验是一种较好的检验早期收缩开裂的实验方法．

英文摘要：

In order to investigate the influence of mineral admixtures on the early shrinkage of concrete under steel bar confinement, the early shrinkage strain and stress of reinforced concrete were measured. Steel ring testing method has been used to investigate the shrinkage crack of different concrete. The test results show that, slag and silica fume obviously increase the early shrinkage of concrete. Limestone powder and fly ash will obviously suppress the early shrinkage, and it shows that the effect of limestone powder is better. Expensive agent can obviously decrease the early shrinkage. It demonstrates that steel ring testing method was a good testing method for checking shrinkage cracking.