用硫酸水泥和波特兰水泥混合物制成的下水道混凝土的性能:现场和实验室研究
Alice Titus Bakera1,2, Amr Aboulela3, Mark G Alexander1
1Department of Civil Engineering, University of Cape Town, Rondebosch 7701, South Africa.
Materials (Basel, Switzerland)
|March 27, 2025
概括
与硫酸盐耐波特兰水泥 (SRPC) 与飞灰 (FA) 相比,硫酸盐硫酸 (CSA) 水泥在下水道环境中表现优越. 在CSA混凝土中,没有质量损失,为下水道建设提供了一个有前途的替代方案.
科学领域:
- 材料科学 材料科学 材料科学
- 土木工程 土木工程是指土木工程.
- 环境工程 环境工程
背景情况:
- 污水环境对混凝土的耐用性构成重大挑战,原因是生物原酸的攻击.
- 与飞灰 (FA) 配合的抗硫酸盐波特兰水泥 (SRPC) 是常用的,但其长期性能令人担忧.
- 硫酸氨酸 (CSA) 水泥正在被探索作为一种潜在的替代粘合剂,以提高耐用性.
研究的目的:
- 为了评估CSA水泥和SRPC + FA粘合剂系统在模拟的"实时"下水道环境中的性能.
- 为了研究这些结合物的恶化机制在生物酸攻击下.
- 为了评估一种基于铁的添加剂 (Hard-Cem®,HC) 在提高混凝土抵抗力的有效性.
主要方法:
- 在下水道环境中暴露25个月的混凝土样本 (CSA,SRPC + FA,SRPC + FA + HC) 的比较性能评估.
- 利用视觉观测,质量和厚度变化测量以及微观结构分析.
- 使用生物酸混凝土 (BAC) 试验来模拟下水道条件并分析漏特性 (pH,Ca,Al).
主要成果:
- CSA混凝土表现出显著改善的性能,没有观察到质量损失.
- 在暴露期间,SRPC + FA混凝土经历了大约三分之一的厚度损失.
- 基于铁的添加剂 (HC) 提供了边际的好处,主要与耐磨/侵蚀性有关,而不是化学攻击.
结论:
- 硫酸 (CSA) 水泥是混凝土下水道建筑的可行的替代粘合剂,因为它的耐用性优越.
- 基于铁的添加剂在化学耐药性方面提供了有限的优势,但可能会增强物理耐用性.
- 需要进一步的研究来了解CSA水泥中高硫酸盐含量对长期性能的影响.
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
166
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
Types of Cement II
86
Portland blast-furnace cement is made by blending Portland cement clinker with granulated blast-furnace slag, which accounts for 25 to 65 percent of the cement's weight. Despite its similarities to ordinary Portland (Type I) cement in terms of fineness and setting times, its early strength is lower, though it achieves comparable strength later on. It's particularly suited for mass concrete structures and marine environments due to its lower heat of hydration and superior sulfate...
86
Pozzolans
92
Pozzolans are siliceous or aluminous materials blended with Portland cement. They interact with the calcium hydroxide produced during the hydration of Portland cement and contribute to improved strength and durability of concrete. The pozzolanic activity, a measure of a pozzolan's effectiveness, is typically assessed using the strength activity index, as defined in ASTM C 618-93, which calculates the ratio of the compressive strength of cement mixtures with and without pozzolan.
Fly ash is...
Fly ash is...
92
Strength of Cement
117
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...
117
Hydration of Cement
185
Hydration of cement is a chemical reaction between cement particles and water. This process occurs primarily through two mechanisms: through-solution and topochemical. In the through-solution process, anhydrous compounds dissolve into their constituents, hydrates form in the solution, and then precipitate from the supersaturated solution. The topochemical process involves solid-state reactions at the cement particle surface. The through-solution process dominates the topochemical process at the...
185
Testing Water Quality
98
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...
98
Types of Cement I
94
Portland cement comes in several types, each with distinct properties and applications based on their chemical composition and hydration characteristics:
Type I (Ordinary Portland Cement) is widely used for general construction where special properties are not required. It has moderate sulfate resistance and heat of hydration.
Type II (Modified Cement) offers moderate resistance to sulfate attack and a lower rate of heat development compared to Type I. It is suitable for structures in...
Type I (Ordinary Portland Cement) is widely used for general construction where special properties are not required. It has moderate sulfate resistance and heat of hydration.
Type II (Modified Cement) offers moderate resistance to sulfate attack and a lower rate of heat development compared to Type I. It is suitable for structures in...
94
