The Effect Of Composition And Aging On Mechanical And Physical Properties In The Manufacture Of Aerated Concrete (porous Concrete)

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The Effect of Composition and Aging on Mechanical and Physical Properties in the Manufacture of Aerated Concrete (Porous Concrete)

Introduction

Porous lightweight concrete, a rapidly growing material in the construction industry, offers innovative solutions for lighter and energy-efficient buildings. Recent research has revealed the impact of material composition and hardening process on the mechanical and physical properties of porous mild concrete. This study aims to investigate the effect of composition and aging on the properties of porous lightweight concrete, providing valuable insights for architects, engineers, and contractors.

Background

Porous lightweight concrete is a type of concrete that contains air pockets or voids, which reduce its density and increase its thermal insulation properties. The material is composed of cement, sand, fly ash, and CaCO3, with aluminum catalysts as the main ingredients. The composition and hardening process play a crucial role in determining the mechanical and physical properties of porous lightweight concrete.

Methodology

This study uses a mixture of cement, sand, fly ash, and CaCO3, with aluminum catalysts as the main ingredients. Two main variables are examined: variations in sand and fly ash composition, as well as drying methods, namely autoclave (1.5 bar pressure) and natural drying (conventional). Variations in sand and fly ash composition are tested in six ratios (60: 0, 50:10, 40:20, 30:30, 20:40, 10:50, and 0:60 % by weight).

The drying process uses a 1.5 bar pressure autoclave with a variety of 20, 40, and 60 minutes, while natural drying is carried out at room temperature with 7, 14, 21, and 28 days. After the drying process, the hardening process (aging) was carried out, followed by testing the characteristics of porous lightweight concrete including density, water absorption, compressive strength, broken strength, shrinkage, thermal conductivity, sound absorption, and microstructure analysis using SEM and XRD.

Results

The results showed that the composition of 50% sand and 10% fly ash in the natural drying process with a 14-day hardening time produced optimum conditions. In this condition, porous lightweight concrete has the following characteristics:

  • Density: 0.91 g/cm3
  • Water absorption: 54%
  • Pressure strength: 2.07 MPA
  • Strong broken: 1 MPA
  • Depreciation: 0.115%
  • Thermal conductivity: 0.237 W/M.K
  • Optimal sound absorption: 12.62% (at a frequency of 125 Hz)
  • Dominant phase: Quartz (Q) and Calcite (C)
  • Average pore size: 100-600 µm

The study also showed that the process of drying quickly with 1.5 bar pressure autoclave, with a hardening time of 40 minutes and a composition of 30% sand and 30% fly ash, reached the optimum condition. This condition produces porous light concrete characteristics:

  • Density: 0.87 g/cm3
  • Water absorption: 59.45%
  • Pressure strength: 4.33 MPA
  • Strong broken: 2.28 MPA
  • Depreciation: 0.012%
  • Thermal conductivity: 0.314 W/M.K
  • Optimal sound absorption: 39.17% (at a frequency of 125 Hz)
  • Dominant phase: Quartz (Q) and Tobermorite (T)
  • Average pore size: 1-200 µm

Discussion

The results of this study reveal that the composition and hardening process play an important role in determining the mechanical and physical properties of porous mild concrete. The use of fly ash as a substitute for some sand not only provides economic efficiency but can also improve material performance. Fast drying with autoclave can produce concrete with a higher compressive strength, while natural drying is more suitable for applications that require low thermal conductivity.

Conclusion

This study provides valuable information for architects, engineers, and contractors in choosing the optimal composition and hardening process for lightweight concrete porous in various applications, in order to produce buildings that are efficient, environmentally friendly, and sustainable. The results of this study can be used to develop new materials and technologies that can improve the performance and sustainability of buildings.

Recommendations

Based on the results of this study, the following recommendations can be made:

  • Use fly ash as a substitute for some sand to improve material performance and reduce costs.
  • Use fast drying with autoclave to produce concrete with higher compressive strength.
  • Use natural drying for applications that require low thermal conductivity.
  • Develop new materials and technologies that can improve the performance and sustainability of buildings.

Future Research Directions

Future research directions can include:

  • Investigating the effect of different types of fly ash on the properties of porous lightweight concrete.
  • Developing new materials and technologies that can improve the performance and sustainability of buildings.
  • Investigating the effect of different drying methods on the properties of porous lightweight concrete.

Limitations of the Study

The limitations of this study include:

  • The study only investigated the effect of composition and aging on the properties of porous lightweight concrete.
  • The study did not investigate the effect of other variables, such as temperature and humidity, on the properties of porous lightweight concrete.
  • The study only used a limited number of samples, which may not be representative of the entire population.

References

  • [1] [Reference 1]
  • [2] [Reference 2]
  • [3] [Reference 3]

Appendices

  • Appendix A: List of materials used in the study.
  • Appendix B: List of equipment used in the study.
  • Appendix C: List of samples used in the study.

Note: The references and appendices are not included in this response as they are not provided in the original text.
Frequently Asked Questions (FAQs) about the Effect of Composition and Aging on Mechanical and Physical Properties in the Manufacture of Aerated Concrete (Porous Concrete)

Q: What is porous lightweight concrete?

A: Porous lightweight concrete is a type of concrete that contains air pockets or voids, which reduce its density and increase its thermal insulation properties.

Q: What are the main ingredients of porous lightweight concrete?

A: The main ingredients of porous lightweight concrete are cement, sand, fly ash, and CaCO3, with aluminum catalysts.

Q: What is the effect of composition on the properties of porous lightweight concrete?

A: The composition of porous lightweight concrete has a significant impact on its properties, including density, water absorption, compressive strength, and thermal conductivity.

Q: What is the effect of aging on the properties of porous lightweight concrete?

A: Aging, or the hardening process, also has a significant impact on the properties of porous lightweight concrete, including density, water absorption, compressive strength, and thermal conductivity.

Q: What is the optimal composition and aging process for porous lightweight concrete?

A: The optimal composition and aging process for porous lightweight concrete is a combination of 50% sand and 10% fly ash in the natural drying process with a 14-day hardening time.

Q: What are the benefits of using fly ash in porous lightweight concrete?

A: Using fly ash in porous lightweight concrete can improve material performance and reduce costs.

Q: What are the benefits of using fast drying with autoclave in porous lightweight concrete?

A: Using fast drying with autoclave in porous lightweight concrete can produce concrete with higher compressive strength.

Q: What are the benefits of using natural drying in porous lightweight concrete?

A: Using natural drying in porous lightweight concrete is more suitable for applications that require low thermal conductivity.

Q: What are the potential applications of porous lightweight concrete?

A: Porous lightweight concrete has a wide range of potential applications, including building insulation, soundproofing, and thermal insulation.

Q: What are the limitations of this study?

A: The limitations of this study include the use of a limited number of samples and the lack of investigation into the effect of other variables, such as temperature and humidity, on the properties of porous lightweight concrete.

Q: What are the future research directions for this study?

A: Future research directions for this study include investigating the effect of different types of fly ash on the properties of porous lightweight concrete, developing new materials and technologies that can improve the performance and sustainability of buildings, and investigating the effect of different drying methods on the properties of porous lightweight concrete.

Q: What are the implications of this study for the construction industry?

A: The implications of this study for the construction industry are significant, as it provides valuable information for architects, engineers, and contractors in choosing the optimal composition and aging process for lightweight concrete porous in various applications.

Q: What are the potential benefits of using porous lightweight concrete in building construction?

A: The potential benefits of using porous lightweight concrete in building construction include improved energy efficiency, reduced greenhouse gas emissions, and increased sustainability.

Q: What are the potential challenges of using porous lightweight concrete in building construction?

A: The potential challenges of using porous lightweight concrete in building construction include the need for specialized equipment and training, the potential for reduced compressive strength, and the need for further research and development.

Q: What are the potential future developments in the field of porous lightweight concrete?

A: The potential future developments in the field of porous lightweight concrete include the development of new materials and technologies that can improve the performance and sustainability of buildings, the use of porous lightweight concrete in new and innovative applications, and the continued research and development of this material.

Note: The questions and answers are not exhaustive and are based on the original text provided.