含孔洞和裂隙混合缺陷的干燥水泥砂浆导热系数相互作用直推预测模型

李云波; 李宗利; 姚希望; 肖帅鹏; 刘士达; 童涛涛

doi:10.13801/j.cnki.fhclxb.20210328.002

含孔洞和裂隙混合缺陷的干燥水泥砂浆导热系数相互作用直推预测模型

doi: 10.13801/j.cnki.fhclxb.20210328.002

李云波^1,,
李宗利^{1, 2, ,},
姚希望^1,,
肖帅鹏^1,,
刘士达^1,,
童涛涛^1,

1.
西北农林科技大学　水利与建筑工程学院，杨凌 712100
2.
西北农林科技大学　旱区农业水土工程教育部重点实验室，杨凌 712100

基金项目: 国家重点研发计划(2017YFC0405101)

详细信息

通讯作者:
李宗利，博士，教授，博士生导师，研究方向为混凝土力学性能及耐久性　E-mail：bene@nwsuaf.edu.cn

中图分类号: TU52；TV43
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- 被引次数: 0
出版历程
- 收稿日期: 2021-01-27
- 修回日期: 2021-03-10
- 录用日期: 2021-03-23
- 网络出版日期: 2021-03-29
- 刊出日期: 2022-01-15

Interaction direct deduction prediction model of thermal conductivity of dry cement mortar with mixed defects of cavities and cracks

LI Yunbo^1
,,
LI Zongli^{1, 2
, ,},
YAO Xiwang^1
,,
XIAO Shuaipeng^1
,,
LIU Shida^1
,,
TONG Taotao^1
,

1.
College of Water Resources and Architectural Engineering, Northwest A & F University, Yangling 712100, China
2.
Key Laboratory of Agricultural Soil and Water Engineering in Arid and Semiarid Areas of Ministry of Education, Northwest A&F University, Yangling 712100, China

摘要

摘要: 水泥砂浆在浇筑、养护和受荷载后易出现缺陷，会显著改变其热传导性能。将水泥砂浆中缺陷分为孔洞和裂隙两种基本类型，基于细观力学理论中的相互作用直推(IDD)估计法，建立了孔洞和裂隙单独存在或同时存在时干燥水泥砂浆等效导热系数预测模型；基于数值模拟结果反推法，提出裂隙随机分布影响函数，改进了IDD模型预测精度；与数值模拟结果进行对比验证其合理性。结果表明，推导出的预测模型充分体现了孔洞、裂隙不同含量及特征对水泥砂浆等效导热系数的影响，预测精度高；提出的裂隙随机分布影响函数具有较高精度和良好适用性；在缺陷率一定的情况下，孔洞对水泥砂浆等效导热系数的影响比裂隙更显著。该预测模型物理基础明确，形式简单，便于工程应用。
- 细观力学 /
- 缺陷 /
- 导热系数 /
- 预测模型 /
- 相互作用直推(IDD)理论 /
- 水泥砂浆
Abstract: Cement mortar is prone to product defects during of pouring, curing and loading, which will significantly change its heat conducting properties. The defects in cement mortar were divided into two basic types of cavities and cracks according to its external characteristics and effects. Based on the interaction direct deduction (IDD) estimation method of mesomechanics theory, the prediction models of equivalent thermal conductivity of dry cement mortar with both cavities and cracks alone or in combination were established. Based on the inverse method of numerical simulation results, the random distribution influence function of the cracks was proposed, which improved the prediction accuracy of the proposed model. The IDD calculation results were compared with the numerical simulation results to verify its rationality and accuracy. The results show that the prediction model fully reflects the influence of different contents and characteristics of cavities and cracks on the equivalent thermal conductivity of cement mortar. The model has high prediction accuracy. The proposed random distribution influence function of cracks has high accuracy and good applicability. In the case of a certain defect rate, the effect of cavities on the equivalent thermal conductivity of cement mortar is more significant than that of cracks. The prediction model has a clear physical basis and a simple form, which is convenient for engineering applications.
- mesomechanics /
- defect /
- thermal conductivity /
- prediction model /
- IDD theory /
- cement mortar

HTML全文

图 1 含孔洞和裂隙的水泥砂浆混合缺陷模型

Figure 1. Mixed defect model with cavities and cracks of cement mortar

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图 2 椭球夹杂示意图

Figure 2. Schematic diagram of ellipsoid inclusion

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图 3 干燥水泥砂浆网格划分图

Figure 3. Meshing diagram of dry cement mortar

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图 4 随机缺陷程序流程图

Figure 4. Flow chart of random defect program

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图 5 平行裂隙模型(ρ=0.05、θ=60°)

Figure 5. Parallel crack model (ρ=0.05, θ=60°)

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图 6 随机裂隙模型(ρ=0.05)

Figure 6. Random crack model (ρ=0.05)

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图 7 裂隙密度对水泥砂浆正交方向导热系数的影响

Figure 7. Influence of crack density on the thermal conductivity of cement mortar in the orthogonal direction

CIDD—Correct IDD solution; IDD—Interaction direct deduction solution; NS—Numerical simulation solution

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图 8 裂隙方向对水泥砂浆导热系数的影响

Figure 8. Influence of crack direction on thermal conductivity of cement mortar

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图 9 裂隙长度与数量对水泥砂浆导热系数的影响

Figure 9. Influence of crack length and quantity on thermal conductivity of cement mortar

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图 10 随机裂隙密度对水泥砂浆导热系数的影响

Figure 10. Effect of random crack density on thermal conductivity of cement mortar

L—Crack length

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图 11 随机孔洞模型(c=0.05)

Figure 11. Random cavity model (c=0.05)

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图 12 不同孔洞特征对水泥砂浆导热系数的影响

Figure 12. Influence of different cavity characteristics on thermal conductivity of cement mortar

d—Cavity diameter

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图 13 孔洞率对水泥砂浆导热系数的影响

Figure 13. Influence of porosity on thermal conductivity of cement mortar

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图 14 含孔洞和裂隙缺陷模型(ρ=0.04、c=0.06)

Figure 14. Defect model with cavities and cracks (ρ=0.04, c=0.06)

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图 15 孔洞率 c 与裂隙密度 ρ 之比对水泥砂浆导热系数影响

Figure 15. Effect of the ratio of porosity c to crack density ρ on thermal conductivity of cement mortar

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