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Updated: Jun 10, 2025

Standard Test Method ASTM D 7998-19 for the Cohesive Strength Development of Wood Adhesives
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评估新方法强度退化从温度升高在亚亚巴特条件下混凝土水化评估的新方法

Adelino V Lopes1, Sergio M R Lopes2

  • 1INESC, Department of Civil Engineering, University of Coimbra, 3030-788 Coimbra, Portugal.

Materials (Basel, Switzerland)
|October 16, 2024
PubMed
概括

高水泥加温度会对混凝土强度产生负面影响. 这项研究开发了一种用于测量温度演变的增压法,发现由于水化热在水泥混凝土中升高,压力强度降低了20%.

关键词:
附带天气条件是附带天气条件.混凝土材料是一种固体材料.混凝土的强度是混凝土的强度.补水热是指水解热的热量.水过程中的水化过程.迫击炮的强度是迫击炮的强度.波特兰水泥公司

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Experimental Protocol to Determine the Chloride Threshold Value for Corrosion in Samples Taken from Reinforced Concrete Structures10:00

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Concreting at elevated temperatures accelerates the hydration process, leading to quicker setting but potentially reducing the long-term strength of the concrete structure. Additionally, low air humidity fosters rapid moisture loss from the concrete, resulting in reduced workability, pronounced plastic shrinkage, and a higher likelihood of crazing.
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Design Example: Managing Concrete Workability01:14

Design Example: Managing Concrete Workability

This example deals with managing the workability of concrete for a raft foundation project under hot weather conditions. Workability is crucial for ensuring the concrete is easy to place, compact, and finish. In this scenario, a slump test — a common method to measure the workability of fresh concrete — initially indicated low workability. This was attributed to the rapid water loss from the concrete mix, exacerbated by the high temperatures causing the course aggregates to heat up.
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Cold Weather Concreting01:27

Cold Weather Concreting

When freshly poured concrete is exposed to freezing temperatures before it has set, the water within the concrete can freeze. This expansion disrupts the setting process, delays chemical reactions necessary for hardening, and increases the volume of pores within the hardened concrete, which weakens its overall structure. If the concrete manages to reach an appreciable strength before it freezes, the damage can be somewhat mitigated.
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Mass Concreting01:22

Mass Concreting

Mass concreting refers to the process of placing large volumes of concrete, such as in gravity dams. The heat generated during the cement hydration process and differential cooling rates within the concrete mass can lead to a temperature gradient, which can result in thermal cracks in the concrete mass.
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