内养护水泥基材料早龄期变形行为

发布时间：2018-02-16 18:10

本文关键词： 高吸水树脂自收缩零点毛细管压力　出处：《硅酸盐学报》2017年11期 　论文类型：期刊论文

【摘要】：利用高吸水树脂(SAP)作为内养护剂抑制水泥基材料的早期收缩开裂已受到广泛研究。然而,掺加SAP制备的内养护水泥基材料自加水24 h内的早期变形行为往往被忽略。由于从塑性到硬化阶段的早期变形较为剧烈,导致在此阶段内的自收缩零点选取对测试结果影响较大。研究了掺加3种不同种类的SAP浆体的全过程收缩变形、毛细管压力及水化放热速率。结果表明:泌水回吸等因素导致的膨胀变形先于SAP引起的膨胀变形出现,SAP的释水历程变化会导致更多的膨胀变形出现;采用维卡仪测试的初凝时间与早期密封条件下的变形速率稳定发展时刻对应较好,毛细管压力发展速率最大时刻与凝结及内应力平衡时刻相对应,更适合作为自收缩测试零点。
[Abstract]:The use of superabsorbent resin (SAP) as an internal curing agent to inhibit early shrinkage cracking of cement-based materials has been extensively studied. The early deformation behavior of cement-based materials with internal curing prepared by adding SAP is often neglected within 24 hours of self-adding water, because the early deformation from plastic to hardening stage is more severe. As a result, the selections of the autogenous 00:00 in this stage have a great influence on the test results. The shrinkage and deformation of SAP slurry mixed with three different kinds of slurry during the whole process are studied. Capillary pressure and hydration heat release rate. The results show that the swelling deformation caused by bleeding and reabsorbing is prior to the expansion deformation caused by SAP. The change of water release history of SAP will lead to more expansion deformation. The initial setting time measured by Vika instrument corresponds well to the stable development time of deformation rate under the condition of early sealing, and the maximum capillary pressure development time corresponds to condensation and internal stress equilibrium time, which is more suitable for self-shrinkage test at 00:00.
【作者单位】：江苏苏博特新材料股份有限公司高性能土木工程材料国家重点实验室;东南大学材料科学与工程学院;
【基金】：国家自然科学基金(51578268,51438003) “973”计划(2015CB655105)项目
【分类号】：TU528

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