收缩、开裂是影响现代混凝土耐久性的主要因素，为评价掺合料对混凝土收缩、开裂的影响，通过圆环开裂试验、收缩试验来评定矿物掺和料对混凝土收缩开裂的性能。圆环开裂试验主要表征混凝土试件在约束条件下抵抗干燥收缩应力的能力，收缩试验则表征试件的体积变形，收缩是开裂的原因，也是影响开裂的最重要因素。结果表明矿渣掺量在一定范围内时可抑制混凝土的开裂，混凝土的自收缩随矿渣掺量的增大而增大，干缩随矿渣掺量的增大而减小。粉煤灰可有效抑制混凝土的开裂，随掺量的增大抑制作用越显著；粉煤灰掺量越大对自收缩的抑制作用越明显，混凝土的干缩略有增大。总的来看，粉煤灰较矿渣可更好地抑制混凝土的收缩与开裂。

Shrinkage and cracking are the primary factors influencing the durability of modern concrete. In order to evaluate the effect of the mineral admixtures on the concrete shrinkage and cracking properities, a lot of tests were conducted by the ring test method and shrinkage experiment. The ring test method mainly reflects the resistance to drying shrinkage stress under the restraining conditions. The shrinkage test mainly reflects the volume deformation. The experimental results show as follows: Slag could inhibit the cracking of concrete within the range of certain proportion. With the increase of slag proportion the selfshrinking of concrete increases, but the drying shrinkage of concrete decreases. Flyash could effectively inhibit the cracking of concrete, with the increase of flyash proportion the concrete cracking could be effectively inhibited. With the increase of? flyash ?proportion the selfshrinking of concrete decreases, but the drying shrinkage of concrete would increase. As a whole, the flyash could effectively control the concrete shrinkage and cracking.