内养生路面混凝土水分传输特性及力学性能

Water Transport Characteristics and Mechanical Properties of Internal Curing Pavement Concrete

关键词:  内养生路面混凝土  水分传输特性  相对湿度  水化  抗弯拉强度

Key words:  internal curing pavement concrete  water transport characteristic  relative humidity  hydration  flexural strength

摘要:

研究了内养生路面混凝土各形式水分在不同龄期的转化规律，探索了高吸水性聚合物（SAP）粒径及掺量对路面混凝土相对湿度、收缩性能及抗弯拉强度的影响，揭示了内养生对抗弯拉强度的影响机理.结果表明：小粒径SAP能够持续释放内养生水对混凝土进行较长时间的养生；内养生路面混凝土在3、7d的减缩率高达6885%和7398%；内养生能够有效削弱路面混凝土垂直方向的湿度梯度，提升材料均匀性；小粒径SAP在释水养生过程中可对混凝土残留孔洞起到良好的水化填充作用，并能增强骨料水泥石界面过渡区（ITZ）黏结强度.

Abstract:

The transformation rule of different forms of water of internal curing pavement concrete was researched at different ages, and the influences of SAP particle size and dosage on the relative humidity, shrinkage performance and flexural strength of pavement concrete were explored. The influence mechanism of internal curing on flexural strength was revealed. The results show that SAP with smaller particle size could release the water gradually for a longer period of time. The shrinkage reduction rate of internal curing pavement concrete on 3，7d was 6885% and 7398%, respectively. Internal curing technology could effectively reduce the vertical humidity gradient of pavement concrete and improve the homogeneity of material. SAP with smaller particle size plays a good hydration filling role on its residual holes, which could enhance the bonding strength of aggregate cement matrix interfacial transition zone(ITZ).