高效减水剂对水泥基材料收缩开裂的影响研究  

Influence of Superplasticizer on Shrinkage and Cracking Behavior of Cement-based Material

作　　者：常粉玲[1] 管宗甫[2] 

机构地区：[1]河南农业大学机电工程学院,郑州450002 [2]郑州大学材料科学与工程学院,郑州450001

出　　处：《中国包装科技博览（混凝土技术）》2012年第6期6-12,共7页China Science and Technology Review

摘　　要：在砂浆水灰比和混凝土水灰比相同的情况下，研究了高效减水剂对砂浆自收缩和干燥收缩的影响及采用平板刀口约束法研究了高效减水剂对混凝土抗裂性能的影响。结果表明：不同品种的高效减水剂对水泥基材料的收缩开裂性能影响不同。萘系和脂肪族减水剂增大砂浆的自收缩和干燥收缩，加剧混凝土的开裂风险；聚羧酸减水剂对砂浆的收缩具有一定的抑制作用，能降低混凝土的开裂风险。在水灰比0．42、掺量0．6％～1．5％范围内，聚羧酸减水剂的掺量对砂浆自收缩和干燥收缩影响不大，混凝土裂缝宽度和开裂面积随其掺量增加而递增。在同流动度（或同塌落度），砂浆自收缩随聚羧酸减水剂掺量的增加而递增，干燥收缩却随其掺量的增加而递减，混凝土裂缝宽度和开裂面积与其掺量呈负相关。At the same water to cement ratio of mortar and concrete, the influence of Superplasticizer on self-shrinkage and drying shrinkage of mortar were investigated and the impact of Superplasticizer on the anti-cracking property of concrete was investigated using flat-restraint method. The results showed that： different species of superplasticizer have varying impact on shrinkage-cracking property of cement-based cementitious material, BNS and aliphatic superplasticizer increase the autogeous shrinkage and drying shrinkage of mortar, increase the risk of cracking problem of concrete, whereas polycarboxylate superplasticizer showed inhibition in some extent for shrinkage of mortar and reduced the risk of cracking problem. At w/c ratio=0.42, dosage varies from 0.6% to 1.5%, the dosage of polycarboxylate superplasticizer exhibits less impact on the autogeous shrinkage and drying shrinkage of mortar, the width and area of concrete cracks increased with the increase of dosage. With the same fluidity （ or the same slump ）, the value of autogeous shrinkage increased with the increase of PCE dosage, while the value of drying shrinkage decreased with the increase of PCE dosage. A negative correlation was found between the width, area of concrete cracks and dosage.

关 键 词：高效减水剂 水泥混凝土 自收缩 干燥收缩 抗裂性能 

分 类 号：TU528.042[建筑科学—建筑技术科学]