| 摘要: |
| 为预测水泥砂浆塑性开裂并对其进行有效预防，采用平板法与八字模法在前期初步建立的水泥砂浆塑性开裂预警机制的基础上增加了预测方程的开裂影响因素（材料组成、约束度及分层度），并扩大了环境参数的范围，由此对水泥砂浆塑性开裂预警机制进行了拓展.结果表明：室内建立的未掺PVA纤维的素砂浆七元本构方程以及掺PVA纤维砂浆的九元本构方程可有效预测室内外水泥砂浆的开裂状况；将二者及其相应的开裂判据结合起来构成水泥砂浆塑性开裂预警机制，可在准确预测素砂浆开裂状况后，通过掺加适量PVA纤维来有效减少砂浆的开裂，从而为保证施工质量提供了新方法. |
| 关键词: 塑性收缩开裂 开裂影响因素 本构方程 预警机制 |
| DOI：10.3969/j.issn.1007-9629.2022.04.001 |
| 分类号:TU528.572 |
| 基金项目:“十三五”国家重点研发计划资助项目（2016YFB0303200） |
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| Expansion of Early Warning Mechanism for Plastic Shrinkage Cracking of Cement Mortar |
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MA Yiping1, WANG Qiongqiong1, FU Jie1, ZHU Wenhao2
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1.Key Laboratory of Advanced Civil Engineering Materials of Ministry of Education，Tongji University， Shanghai 201804， China;2.Shanghai Institute of Space Power-Sources， Shanghai 200245， China
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| Abstract: |
| In order to predict the plastic shrinkage cracking of cement mortar and prevent it effectively， the cracking factors of the prediction equation（composition， constrained degree and segregated degree） were added and the range of the environmental parameter was expanded by flat plate method and eight-character model method based on the initial establishment of early warning mechanism for plastic shrinkage cracking of cement mortar.Thus the early warning mechanism for plastic shrinkage cracking of cement mortar was expanded. The results show that the seven-element constitutive equation of plain cement mortar without fibers and the nine-element constitutive equation of cement mortar with polyvinyl alcohol（PVA） fibers are established which can effectively predict the cracking of cement mortar. In addition， through combining the constitutive equations and their cracking criteria， the early warning mechanism for plastic shrinkage cracking of mortar is established， which can effectively reduce cracking by adding suitable PVA fibers after predicting the cracking condition of plain mortar correctly and ensure a good construction quality. |
| Key words: plastic shrinkage cracking influencing cracking factor constitutive equation early warning mechanism |
