论文总字数：23146字

摘 要

碱-集料反应（AAR）是影响水泥混凝土耐久性的主要因素之一。因AAR发生之后，混凝土结构很难修复，曾被喻为混凝土的“癌症”。石灰石微粉作为矿物掺合料对混凝土抗AAR性能无明显不利影响。白云石作为石灰石的伴生矿物，在石灰石微粉的使用过程中不可避免地引入白云石微粉。而部分含白云石的集料可与碱发生碱-碳酸盐反应(ACR)导致混凝土膨胀开裂。然而，白云石微粉对AAR以及对水化产物的影响尚不明确。本文以石灰石微粉作参照，首先研究了不同掺量的白云石微粉对水泥净浆膨胀性能的影响。在此基础上，采用改进中国快速砂棒法，研究了白云石微粉单掺及与偏高岭土复掺对活性硅质集料和含白云石的活性碳酸盐集料膨胀性能的影响，并采用XRD对水化产物进行了表征。结果显示：

（1）与石灰石微粉相比，含白云石微粉的水泥净浆膨胀率高于石灰石微粉体系。白云石微粉可促进浆体微膨胀，且掺量愈大促进作用愈明显；（2）单掺白云石微粉对水泥抗ASR性能的影响与单掺石灰石微粉相当。而复掺白云石微粉和偏高岭土对水泥抗ASR性能的影响与复掺石灰石微粉和偏高岭土相当。这表明白云石微粉并没有劣化水泥抗ASR性能；（3）单掺白云石微粉对水泥抗ACR性能的影响与单掺石灰石微粉相当。而复掺白云石微粉和偏高岭土对水泥抗ACR性能的影响与复掺石灰石微粉和偏高岭土相当。这表明白云石微粉并没有劣化水泥抗ACR性能；（4）白云石微粉在水泥体系中反应生成了水滑石和水镁石，这是导致含白云石微分浆体微膨胀的主要原因。

关键字：抗AAR性能 白云石微粉 石灰石微粉

Abstract

As one of the significant factors that affect the durability of concrete，concrete structure was severely damaged and can never be repaired when the reaction occur, alkali - aggregate reaction is known as "cancer" of concrete. Limestone as mineral admixtures has no significant adverse effect on the concrete anti-AAR. Dolomite and Limestone are associated Minerals. Aggregate, which contains dolomite, will cause Alkali - carbonate reaction. But it is not certain that whether dolomite powder can cause such a reaction. This issue designed different amounts of dolomite powder incorporated cement paste to study the impact on cement expansion and using CAMBT to study dolomite powder’s impact on ASR and ACR of cement, which contains silicon aggregate and dolomitic aggregate. The results have proved the following conclusions:

(1) Compared to the limestone powder concerned, dolomite’s role in promoting the expansion of cement paste is more effective. With the increase of incorporation, its role in promoting the expansion is more and more significant;

(2) Doped single, complex mixed dolomite have no significant deterioration of concrete anti AAR performance.

(3) Dolomite powder and metakaolin complex mixed concrete has similar ability with limestone powder and metakaolin cimplex mixed or metakaolin concrete in inhibiting AAR expansion.

(4) Dolomite reacts to hydrotalcite and brucite, which promote micro expansive cement. Dolomite has no significant effect on the performance of cement anti AAR.

Key words: Anti-AAR；dolomite powder；limestone powder

目 录

摘要 I

ABSTRACT II

目录 III

第一章 绪论 1

1.1 碱-集料反应 1

1.1.1 概述 1

1.1.2 ASR 3

1.1.3 ACR 4

1.2 国内外研究现状 6

1.2.1 偏高岭土抗AAR研究现状 6

1.2.2 石灰石微粉抗AAR研究现状 7

1.4.3 白云石微粉抗AAR性能研究现状 8

第二章原材料及实验方法 9

2.1原材料 9

2.2 实验仪器及设备 10

2.3 白云石微粉对水泥净浆膨胀性能的影响 10

2.3.1配料比 10

2.3.2实验方法 10

2.4 白云石微粉对AAR性能的影响 12

2.4.1 配料比 12

2.4.2 实验方法 12

第三章 实验结果及讨论 14

3.1 白云石微粉对水泥净浆膨胀的影响 14

3.2 白云石微粉抗AAR性能 15

3.2.1 白云石微粉抗ASR性能 15

3.2.2 白云石微粉抗ACR性能 18

3.3 水泥净浆化产物XRD分析 20

3.4 含白云石微粉浆体水化产物XRD分析 22

第四章 结论与展望 25

5.1 结论 25

5.2 展望 25

参考文献 26

致谢 29

1. 绪论

1.1 碱-集料反应

1.1.1 概述

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