混凝土砂的压力强度和pH值的发展,在加快固化下结合了大量补充性混凝土材料
Sumra Yousuf1, Muhammad Rizwan2, Belal Alsubari3
1Department of Building and Architectural Engineering, Faculty of Engineering & Technology, Bahauddin Zakariya University, 60000, Multan, Pakistan.
Heliyon
|February 26, 2025
概括
基于水泥的材料 (CBMs) 的pH值对于混凝土的耐用性至关重要. 虽然飞灰和渣对pH的影响最小,但经过处理的棕油燃料灰显著降低了CBM的性,可能会影响长期耐用性.
科学领域:
- 土木和材料工程 土木和材料工程
- 建筑科学 建筑科学
- 混凝土技术 混凝土技术
背景情况:
- 混凝土的耐用性与基于水泥的材料 (CBM) 的pH值密切相关.
- 补充性水泥材料 (SCM) 可以降低CBM的pH值,因为pozolanic反应,引起了人们对高容量的SCM在混合水泥中的使用的担忧.
- 了解SCM对CBM pH的影响对于可持续建筑实践至关重要.
研究的目的:
- 在早期和晚期固化阶段调查结合50%补充水泥材料 (SCMs) 的水泥砂的pH演变.
- 为了比较普通波特兰水泥 (OPC) 与飞灰 (FA),磨砂颗粒高炉渣 (GGBS) 和处理的棕油燃料灰 (TPFA) 的pH行为.
- 评估SCM诱导的pH值变化对混凝土结构长期耐用性的影响.
主要方法:
- 用50%的OPC替换为FA,GGBS和TPFA的水泥砂的制备.
- 监测各种固化年龄的砂pH值.
- 使用热重力测量分析 (TGA) 和X射线衍射 (XRD) 来支持pH值的发现.
主要成果:
- 有FA和GGBS的砂在5个月后呈现轻微的pH值下降,保持在11.5的关键耐用性值以上.
- 与TPFA混合的砂显示了大约14%的显著pH值降低,这表明对性有很大影响.
- 该研究发现,除了Ca (OH) 2消耗之外的因素,如SCM的化学成分和反应性,影响CBM的pH.
结论:
- 飞灰和磨砂颗粒高炉渣显示了可接受的pH值水平,用于长期的混凝土耐用性,当使用50%的替代品时.
- 大量的经过处理的棕油燃料灰可能会损害混凝土的耐用性,因为水泥基材料的性显著降低.
- 混合水泥的化学特性和反应性在确定混合水泥系统的pH值和潜在耐用性方面发挥着至关重要的作用.
关键词:
() 2 () 2 () 2 () 2 () 2 () 2 () 2 () 2 () 2 () 2 () 2 () 2 () 2 () 2 () 2 () 2 () 3 () 2 () 2 () 2 () 2 () 3 () 2 () 2 () 3 () () () ) () ) () ) () ) () ) () ) () ) () ) () ) () () ) () () ) ()治疗治疗治疗治疗治疗砂:一个砂.补充的固材料 补充的固材料它们的pH值是pH值.更多相关视频
05:36Production and Analysis of Sporosarcina pasteurii Biocement Bricks Using Custom 3D-Printed Molds for Unconfined Compression Tests
Published on: March 7, 2025
173
06:27Expression of Cementitious Pore Solution and the Analysis of Its Chemical Composition and Resistivity Using X-ray Fluorescence
Published on: September 23, 2018
9.1K
相关概念视频
Strength of Cement
120
Strength tests for cement are not performed directly on neat cement paste due to difficulty in obtaining consistent, reliable specimens. Instead, cement is typically tested in the form of cement-sand mortar.
For compressive strength tests, ASTM C 109-05 standards prescribe a cement-sand mix ratio of 1:2.75 and a water/cement ratio of 0.485 for making 2-inch cubes. These cubes are mixed, cast, and cured in saturated lime water at 23°C until testing. Flexural strength testing, outlined in...
For compressive strength tests, ASTM C 109-05 standards prescribe a cement-sand mix ratio of 1:2.75 and a water/cement ratio of 0.485 for making 2-inch cubes. These cubes are mixed, cast, and cured in saturated lime water at 23°C until testing. Flexural strength testing, outlined in...
120
Testing Water Quality
102
When the quality of water for concrete preparation is uncertain, its impact on the setting time of cement and compressive strength of mortar is assessed by comparison with de-ionized or distilled water benchmarks. American Society for Testing and Materials (ASTM) C1602 requires the setting times to be within 90 minutes of the control, British Standard (BS) 3146:1980 allows a 30-minute variance in the initial setting, while British Standards European Norm (BS EN) 1008 specifies initial setting...
102
Mortar Properties
107
Mortar properties encompass a range of characteristics crucial for construction and masonry work, including workability, water retention, bond strength, durability, compressive strength, volume change, and appearance. Workability refers to mortar's ability to be easily applied and manipulated without sagging or falling off surfaces, which is important for efficient masonry unit placement and alignment. Water retention is essential to prevent the mortar from losing moisture too quickly to...
107
Soundness of Cement
134
The soundness of cement refers to the ability of cement paste to retain its volume after setting. Unsound cement can lead to expansion and structural damage due to the presence of free lime, magnesia, and calcium sulfate. Free lime hydrates very slowly, expanding and causing unsoundness, which is difficult to detect because it intercrystallizes with other compounds. Magnesia also reacts with water, forming crystals that can disrupt the cement's structure. Calcium sulfate can create...
134
Curing of Concrete
84
The hydration of cement takes place within the water-filled capillary pores. However, environmental elements can disrupt this process by evaporating water from the concrete surfaces. Sealed concrete with a water-cement ratio below 0.5 experiences self-desiccation, leading to water loss. The water loss in concrete is mitigated by curing. This technique involves keeping the concrete saturated to maintain the necessary temperature and moisture conditions, to optimally fill the spaces in the cement...
84
Strength and Heat of Hydration
201
The hydration of cement is an exothermic reaction in which heat is generated as cement hydrates. This heat of hydration is critical to cement's strength development. The rate at which this heat is generated affects the temperature rise, with a majority of the heat being released early in the hydration process, half within the first three days, and about 75% within the first week.
The heat of hydration for each cement compound is significant; for instance, tricalcium aluminate (C3A) and...
The heat of hydration for each cement compound is significant; for instance, tricalcium aluminate (C3A) and...
201
