研究了约束状况、失水条件及试件厚度等因素对水泥砂浆塑性收缩开裂性能的影响 ,结果表明 :( 1 )增加钢筋框中部约束或取消钢筋框均可减少砂浆塑性收缩开裂性能 ;底部凹凸状约束及面层铺设钢丝网可使砂浆塑性开裂有所减小 ,但不能消除塑性开裂现象 ;基本去除约束的准自由状态可使砂浆免除塑性收缩开裂 .( 2 )失水条件对砂浆塑性收缩开裂有明显影响 .灯与电风扇同时开启所形成的“风吹日晒”比单纯“风吹”、“日晒”更易于使砂浆塑性收缩开裂 ;加强抹面处理可使塑性收缩开裂减小 ;维持较长时间的洒水养护可消除塑性开裂现象 .( 3 )增加试件厚度可减少砂浆的塑性收缩开裂 ;混凝土的抗塑性收缩开裂能力比砂浆强 The effects of restraint conditions, water loss conditions and specimen thickness on the plastic shrinkage cracking of cement mortar were studied. The results show that: (1) The plastic shrinkage and cracking behavior of mortar can be reduced by adding restraints in the middle of steel box or eliminating the steel frame; The shape constraint and surface laying of steel mesh can reduce the plastic cracking of mortar, but it can not eliminate the phenomenon of plastic cracking. The quasi-free state of the constraint can make the mortar free from plastic shrinkage and cracking. (2) Cracking has a significant impact.When the lamp and the fan open at the same time formed by the “wind and sun” than the simple “wind”, “sun” more easily plastic shrinkage cracking mortar; strengthen the plastic surface treatment can reduce plastic shrinkage cracking; Maintaining sprinkler curing for a long time can eliminate the plastic cracking phenomenon. (3) Increasing the thickness of the specimen can reduce the plastic shrinkage and cracking of the mortar; the plastic shrinkage and cracking resistance of the concrete is stronger than that of the mortar