天然轻骨料混凝土外掺粉煤灰力学性能及耐久性能试验研究

分类号 TU528.2 U D C 624 学校代码 10129 学 号 2010206002

天然轻骨料混凝土外掺粉煤灰力学性能及耐久性能试验研究 Experimental Research on Mechanics and Durability of

Natural Lightweight Aggregate Concrete by External Mixing

Fly Ash

申 请 人：韩俊涛

学科门类：工 学

学位专业: 结构工程

研究方向：建筑新材料

指导教师：申向东 教授

论文提交日期：二○一三年六月

摘 要

本文以天然浮石为粗骨料，利用工业废料粉煤灰，采用外掺法，配制了强度等级为LC50的天然轻骨料混凝土。针对不同掺量的粉煤灰，研究了天然轻骨料混凝土的基本力学性能和部分耐久性能。

试验通过掺加0%、20%、30%和40%体积的粉煤灰替代相同体积的砂，配制了4组轻骨料混凝土，研究了3d、14d、21d、28d、60d和90d的抗压强度与28d的轴心抗压强度和弹性模量；研究了25次、50次、75次、100次、125次、150次和200次盐溶液快速冻融的动弹性模量；研究了5次、15次、30次、45次、50次、55次和60次抗硫酸盐侵蚀的质量损失和抗压强度。

本文通过以上试验，结合试验数据，对抗压强度与龄期的关系、抗压强度与粉煤灰掺量的关系进行了分析，选出了抗压强度最优组；对快速冻融循环试验盐溶液试验组与清水对比组的相对动弹性模量进行了分析，探讨了盐冻耦合环境下轻骨料混凝土破坏机理；对在硫酸盐侵蚀环境下抗压强度与干湿循环次数关系、干湿循环相对质量损失进行了分析，建立了应力-应变曲线，研究了硫酸盐侵蚀对轻骨料混凝土的影响，探讨了粉煤灰在混凝土中抗硫酸盐侵蚀的作用机理。同时，利用SEM电镜试验，对部分试验进行了微观分析。通过试验研究，得出了较为满意的试验结果，为今后天然轻骨料混凝土的发展提供试验依据。

关键词：粉煤灰；外掺法；天然浮石；轻骨料混凝土；力学性能；耐久性能

Experimental Research on Mechanics and Durability of Natural Lightweight Aggregate Concrete by External Mixing Fly Ash

Abstract

In this article, based on natural pumice for coarse aggregate, through external addition method by mixing with fly ash from industrial waste, made up LC50 strength grade of natural lightweight aggregate concrete. According to the different proportion of fly ash, researched the basic mechanical properties and durability of it.

Experimental by adding 0%, 20%, 30% and 40% volume of fly ash to replace the same volume of sand, made up of 4 groups lightweight aggregate concrete(LAC). Study of concrete in the 3d, 14d, 21d, 28d, 60d and 90d compressive strength and 28d of the elastic modulus and axial compressive strength; study of concrete in salt solution rapid freeze-thaw cycle 25times, 50times, 75times, 100times, 125times, 150times and 200times of the dynamic modulus of elasticity; study of concrete resistance to sulphate attack 5 times, 15 times, 30 times, 45 times, 50 times, 55 times and 60 times of the mass loss and compressive strength.

Through the above tests and experimental data obtained, the analysis of the relationship between compressive strength and age and fly ash content are choosed optimal group; the analysis of salt solution test group and contrast group water relative dynamic modulus of elasticity, which used test method for rapid freezing and thawing. Discusses the failure mechanism of LWAC in the salt freezing coupled environment; the analysis of the relation for LWAC compressive strength and dry-wet cycle times, relative mass loss, establishment of the stress-strain curve and research the impact of sulphate attack of LWAC, discusses the influence of fly ash in concrete resistance to sulphate attack mechanism. Meanwhile, using SEM test analysis on the part of the test. With the test studies, obtained more satisfactory test results, provided the experimental basis for the development of natural lightweight aggregate concrete.

Key Word: Fly ash; External addition method; Natural pumice; Lightweight aggregate

concrete; Mechanical property; Durability

Directed by: prof. SHEN Xiangdong

Applicant for Master degree: HAN Juntao （structural engineering）

(College of Water Conservancy and Civil Engineering,Inner Mongolia Agricultural University,Huhhot 010018,China)

目 录

1 绪论 ...................................................................... 1

1.1 研究背景及课题提出 .................................................... 1

1.2 轻骨料混凝土研究概况 .................................................. 2

1.2.1 轻骨料分类 .......................................................... 2

1.2.2 轻骨料混凝土国外研究概况 ............................................ 2

1.2.3 轻骨料混凝土国内研究概况 ............................................ 4

1.3 粉煤灰研究概况 ........................................................ 5

1.3.1 粉煤灰分类 .......................................................... 5

1.3.2 粉煤灰在水泥基材中的作用 ............................................ 5

1.3.3 粉煤灰掺入方式 ...................................................... 6

1.4 论文研究意义 .......................................................... 6

1.5 论文研究内容 .......................................................... 6

2 试验材料、方案设计及试验方法 .............................................. 7

2.1 试验材料及其性能 ...................................................... 7

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