Effects of novel polymer-type shrinkage-reducing admixture on early age autogenous deformation of cement pastes
Effects of novel polymer-type shrinkage-reducing admixture on early age autogenous deformation of cement pastes
复制标题
DOI：
10.1016/j.cemconres.2017.08.007
复制
发表时间：
2017-10
影响因子：
11.4
通讯作者：
Wenqiang Zuo;Pan Feng;Peihua Zhong;Q. Tian;Gao Nanxiao;Yujiang Wang;Cheng Yu;C. Miao
中科院分区：
文献类型：
--
作者：
Wenqiang Zuo;Pan Feng;Peihua Zhong;Q. Tian;Gao Nanxiao;Yujiang Wang;Cheng Yu;C. Miao
本研究旨在探讨具有减水功能的新型聚合物减缩剂(SRA)的自收缩机理。为了进行比较，还使用了传统的聚醚型SRA。综合考察了自生变形、水化速率、内部相对湿度(RH)、电阻率、孔溶液中离子和SRAS浓度以及水泥浆体晶体含量的变化规律。与聚醚型SRA混合料在早期具有膨胀期不同，聚合物型SRA混合料的收缩演化相对缓慢和单调。结果表明，与聚醚型SRA相比，新型SRA对水泥水化的延迟和调节作用明显影响水泥浆体的微观结构发展和各项性能的演变。此外，自干燥状态引起的毛细压力和结晶压力引起的膨胀应力都有助于SRAS对水泥浆体自生变形的减缩行为。
This study aims to investigate the autogenous shrinkage-reducing mechanisms of the novel polymer-type shrinkage-reducing admixture (SRA) with water-reducing function. For comparison, the traditional polyether-type SRA was also used. The development of autogenous deformation, hydration rate, internal relative humidity (RH), electrical resistivity, ions and SRAs concentration in pore solutions and crystal content of cement pastes were comprehensively investigated. Unlike the polyether-type SRA mixture which has an expansion period at early age, a relatively slow and monotonous evolution of shrinkage was observed for the polymer-type SRA mixture. It is concluded that the delay and regulation effects on cement hydration of the novel SRA obviously influence the microstructure development and the evolutions of various performances of cement pastes comparing to the polyether-type SRA. Furthermore, both the self-desiccation status induced capillary pressure and the crystallization pressure induced expansion stress contribute to the shrinkage-reducing behaviors of SRAs on the autogenous deformation of the cement pastes.